- What's New
- Function Overview
- Product Bulletin
-
Service Overview
- GaussDB(DWS) Infographics
- What Is GaussDB(DWS)?
- Data Warehouse Types
- Data Warehouse Flavors
- Advantages
- Application Scenarios
- Functions
- Concepts
- Related Services
- Security
- GaussDB(DWS) Permissions Management
- GaussDB(DWS) Access
- Restrictions
- Technical Support
- Service Quotas
- GaussDB(DWS) Technical Specifications
-
Billing
- GaussDB(DWS) Billing Overview
- Billing Modes
- Item
- Billing Examples
- Billing Mode Change
- Renewal
- Bills
- Arrears
- Stopping Billing
- Cost Management
-
Billing FAQs
- How Can I Try Out GaussDB(DWS) for Free?
- Why Was I Deducted Fees After My GaussDB(DWS) Free Trial Expired?
- Why Can't I See a Cluster After I Subscribe to a Free GaussDB(DWS) Trial?
- Does Pay-per-Use Billing Stop When My Cluster Stops?
- Why Is the Purchase Button Unavailable When I Create a Cluster?
- How Do I Unfreeze a Cluster?
- Can I Freeze or Shut Down a GaussDB(DWS) Cluster to Stop Billing?
-
Getting Started
- Checkpoint Vehicle Analysis
- Supply Chain Requirement Analysis of a Company
- Operations Status Analysis of a Retail Department Store
- Creating a Time Series Table
- Best Practices of Hot and Cold Data Management
- Best Practices for Automatic Partition Management
- Creating a Cluster and Connecting to It
- Using CDM to Migrate MySQL Data to the GaussDB(DWS) Cluster
- Using DLI Flink Jobs to Write Kafka Data to GaussDB(DWS) in Real Time
- Basic SQL Operations
-
Database Quick Start
- Before You Start
- Creating and Managing Databases
- Planning a Storage Model
- Creating and Managing Tables
- Loading Sample Data
- Querying System Catalogs
- Creating and Managing Schemas
- Creating and Managing Partitioned Tables
- Creating and Managing Indexes
- Creating and Managing Views
- Creating and Managing Sequences
- Creating and Managing Scheduled Tasks
- Getting Started with Common Practices
-
User Guide
- Using GaussDB(DWS)
- Preparations
- Creating a GaussDB(DWS) Cluster
-
Connecting to a GaussDB(DWS) Cluster
- Overview
- Obtaining the Connection Address of a GaussDB(DWS) Cluster
- Using a Visualization Tool to Connect to a GaussDB(DWS) Cluster
- Using the CLI to Connect to a GaussDB(DWS) Cluster
-
Using a Third-Party Database Adapter for GaussDB(DWS) Cluster Connection
-
Using the JDBC and ODBC Drivers to Connect to a Cluster
- Development Specifications
- JDBC Version Description
- Downloading the JDBC or ODBC Driver
- Using JDBC to Connect to a Cluster
- Configuring JDBC to Connect to a Cluster (Load Balancing Mode)
- Configuring JDBC to Connect to a Cluster (IAM Authentication Mode)
- Third-party Connection Pool of the JDBC Configuration Database
- Using ODBC to Connect to a Cluster
- Using the Third-Party Function Library psycopg2 of Python to Connect to a Cluster
- Using the Python Library PyGreSQL to Connect to a Cluster
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Using the JDBC and ODBC Drivers to Connect to a Cluster
- Creating a GaussDB(DWS) Database and User
- Migrating Service Data to a GaussDB(DWS) Cluster
- GaussDB(DWS) Cluster Data Security and Encryption
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GaussDB(DWS) Cluster Management
- Viewing GaussDB(DWS) Cluster Details
- Checking the GaussDB(DWS) Cluster Status
- Viewing the GaussDB(DWS) Cluster Topology
- Managing GaussDB(DWS) Cluster Connections
- GaussDB(DWS) Resource Load Management
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Managing GaussDB(DWS) Logical Clusters
- Logical Cluster Overview
- Adding/Deleting a Logical Cluster
- Managing Logical Clusters
- Elastically Adding or Deleting a Logical Cluster
- Tutorial: Converting a Physical Cluster That Contains Data into a Logical Cluster
- Tutorial: Dividing a New Physical Cluster into Logical Clusters
- Tutorial: Setting a Read-Only Logical Cluster and Binding It to a User
- Modifying GUC Parameters of the GaussDB(DWS) Cluster
- Managing GaussDB(DWS) Tags
- Resetting the Password the GaussDB(DWS) Database Administrator
- Starting, Stopping, and Deleting a GaussDB(DWS) Cluster
- Managing Enterprise Projects
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GaussDB(DWS) Cluster O&M
- Viewing GaussDB(DWS) Cluster Monitoring Information on the Monitoring Panel (DMS)
- Viewing GaussDB(DWS) Cluster Monitoring Information on Cloud Eye
- Monitoring and Diagnosing Top SQL Statements in a GaussDB(DWS) Cluster
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Viewing GaussDB(DWS) Cluster Alarms
- Alarm Management
- Alarm Rules
- Alarm Subscriptions
-
Alarm Handling
- DWS_2000000001 Node CPU Usage Exceeds the Threshold
- DWS_2000000006 Node Data Disk Usage Exceeds the Threshold
- DWS_2000000009 Node Data Disk I/O Usage Exceeds the Threshold
- DWS_2000000012 Node Data Disk Latency Exceeds the Threshold
- DWS_2000000016 Data Spilled to Disks of the Query Statement Exceeds the Threshold
- DWS_2000000017 Number of Queuing Query Statements Exceeds the Threshold
- DWS_2000000018 Queue Congestion in the Default Cluster Resource Pool
- DWS_2000000020 Long SQL Probe Execution Duration in a Cluster
- DWS_2000000023 A Vacuum Full Operation That Holds a Lock for A Long Time Exists in the Cluster
- DWS_2000000027 Memory Usage of a GaussDB(DWS) Cluster Node Exceeds the Threshold
- DWS_2000000028 Dynamic Memory Usage of GaussDB(DWS) Cluster Nodes Exceeds the Threshold
- DWS_2000000029 Usage of a GaussDB(DWS) Cluster Resource Pool Exceeds the Threshold
- DWS_2000000030 Session Usage in a GaussDB(DWS) Cluster Exceeds the Threshold
- DWS_2000000031 Active Session Usage in a GaussDB(DWS) Cluster Exceeds the Threshold
- DWS_2000000032 Number of Database Deadlocks in a GaussDB(DWS) Cluster Exceeds the Threshold
- DWS_2000000033 GaussDB(DWS) Cluster Database Session Usage Exceeds the Threshold
- Viewing and Subscribing to GaussDB(DWS) Cluster Events
- Common O&M Commands of GaussDB(DWS)
- Backing Up and Restoring a GaussDB(DWS) Cluster
- Scaling GaussDB(DWS) Cluster Nodes
- Changing GaussDB(DWS) Cluster Specifications
- GaussDB(DWS) Cluster DR Management
- Upgrading a GaussDB(DWS) Cluster
- GaussDB(DWS) Cluster Log Management
- Handling Abnormal GaussDB(DWS) Clusters
- Reclaiming GaussDB(DWS) Space Using Vacuum
- Authorizing a GaussDB(DWS) Cluster O&M Account
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Best Practices
-
Import and Export
- Best Practices for DataImport
- GDS Practice Guide
- Migrating Data from OBS Buckets to a GaussDB(DWS) Cluster
- Using GDS to Import Table Data from a Remote Server to a GaussDB(DWS) Cluster
- Importing Table Data from MRS Hive to a GaussDB(DWS) Cluster
- Enabling Cross-Cluster Access of Hive Metastore Through an External Schema
- Importing Table Data from DLI to a GaussDB(DWS) Cluster
- Migrating Data Between GaussDB(DWS) Clusters Using Foreign Tables
- Exporting ORC Data from a GaussDB(DWS) Cluster to an MRS Cluster
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Data Migration
- Using CDM to Migrate Oracle Data to a GaussDB(DWS) Cluster
- Using CDM to Migrate MySQL Data to a GaussDB(DWS) Cluster
- Using DRS to Synchronize MySQL Table Data to a GaussDB(DWS) Cluster in Real Time
- Using a Flink Job of DLI to Synchronize Kafka Data to a GaussDB(DWS) Cluster in Real Time
- Using a Flink Job of DLI to Synchronize MySQL Data to a GaussDB(DWS) Cluster in Real Time
- Migrating Data Between GaussDB(DWS) Clusters Using GDS
- Data Analytics
- Decoupled Storage and Compute
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Data Development
- Cutting Costs by Switching Between Cold and Hot Data Storage in GaussDB(DWS)
- Cutting Partition Maintenance Costs for the E-commerce and IoT Industries by Leveraging GaussDB(DWS)'s Automatic Partition Management Feature
- Improving Development Efficiency by Leveraging GaussDB(DWS)'s View Decoupling and Rebuilding Function
- Best Practices for Using HStore Tables
- Best Practices of GIN Index
- Encrypting and Decrypting Data Columns
- Managing Data Permissions Through Views
- Database Management
-
Performance Tuning
-
Optimizing Table Structure Design to Enhance GaussDB(DWS) Query Performance
- Before Optimization: Learning Table Structure Design
- Step 1: Creating an Initial Table and Loading Sample Data
- Step 2: Testing System Performance of the Initial Table and Establishing a Baseline
- Step 3: Optimizing a Table
- Step 4: Creating Another Table and Loading Data
- Step 5: Testing System Performance in the New Table
- Step 6: Evaluating the Performance of the Optimized Table
- Appendix: Table Creation Syntax
- Analyzing SQL Statements That Are Being Executed to Handle GaussDB(DWS) Performance Issues
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Optimizing Table Structure Design to Enhance GaussDB(DWS) Query Performance
- Cluster Management
-
Import and Export
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Data Migration and Synchronization
- Data Migration to GaussDB(DWS)
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Importing Data
- Importing Data from OBS in Parallel
- Using GDS to Import Data from a Remote Server
- Importing Data from MRS to a Cluster
- Importing Data from One GaussDB(DWS) Cluster to Another
- GDS-based Cross-Cluster Interconnection
- Using Kettle to Import Data
- Using a gsql Meta-Command to Import Data
- Running the COPY FROM STDIN Statement to Import Data
- Full Database Migration
- Real-time Import
- Metadata Migration
- Exporting Data
- Other Operations
-
Developer Guide
-
Standard data warehouse (9.1.0.x)
- Before You Start
-
GaussDB(DWS) Development Design Proposal
- Overview
- GaussDB(DWS) Connection Management Specifications
- GaussDB(DWS) Object Design Specifications
- GaussDB(DWS) SQL Statement Development Specifications
- GaussDB(DWS) Stored Procedure Development Specifications
- Detailed Design Rules for GaussDB(DWS) Objects
-
Creating and Managing GaussDB(DWS) Database Objects
- Creating and Managing GaussDB(DWS) Databases
- Creating and Managing GaussDB(DWS) Schemas
- Creating and Managing GaussDB(DWS) Tables
- Selecting a GaussDB(DWS) Table Storage Model
- Creating and Managing GaussDB(DWS) Partitioned Tables
- Creating and Managing GaussDB(DWS) Indexes
- Creating and Using GaussDB(DWS) Sequences
- Creating and Managing GaussDB(DWS) Views
- Creating and Managing GaussDB(DWS) Scheduled Tasks
- Viewing GaussDB(DWS) System Catalogs
- Syntax Compatibility Differences Among Oracle, Teradata, and MySQL
- GaussDB(DWS) Database Security Management
- GaussDB(DWS) Data Query
- GaussDB(DWS) Sorting Rules
- GaussDB(DWS) User-Defined Functions
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GaussDB(DWS) Stored Procedure
- Overview
- Converting Data Types in GaussDB(DWS) Stored Procedures
- GaussDB(DWS) Stored Procedure Array and Record
- GaussDB(DWS) Stored Procedure Declaration Syntax
- Basic Statements of GaussDB(DWS) Stored Procedures
- Dynamic Statements of GaussDB(DWS) Stored Procedures
- GaussDB(DWS) Stored Procedure Control Statements
- Other Statements in a GaussDB(DWS) Stored Procedure
- GaussDB(DWS) Stored Procedure Cursor
- GaussDB(DWS) Stored Procedure Advanced Package
- GaussDB(DWS) Stored Procedure Debugging
- Using PostGIS Extension
- Using JDBC or ODBC for GaussDB(DWS) Secondary Development
- GaussDB(DWS) Resource Monitoring
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GaussDB(DWS) Performance Tuning
- Overview
- Performance Diagnosis
- System Optimization
-
SQL Tuning
- SQL Query Execution Process
- SQL Execution Plan
- Execution Plan Operator
- SQL Tuning Process
- Updating Statistics
- Reviewing and Modifying a Table Definition
- Advanced SQL Tuning
- Configuring Optimizer Parameters
- Hint-based Tuning
- Routinely Maintaining Tables
- Routinely Recreating an Index
- Automatic Retry upon SQL Statement Execution Errors
- Query Band Load Identification
-
SQL Tuning Examples
- Case: Selecting an Appropriate Distribution Column
- Case: Creating an Appropriate Index
- Case: Adding NOT NULL for JOIN Columns
- Case: Pushing Down Sort Operations to DNs
- Case: Configuring cost_param for Better Query Performance
- Case: Adjusting the Partial Clustering Key
- Case: Adjusting the Table Storage Mode in a Medium Table
- Case: Reconstructing Partition Tables
- Case: Adjusting the GUC Parameter best_agg_plan
- Case: Rewriting SQL Statements and Eliminating Prune Interference
- Case: Rewriting SQL Statements and Deleting in-clause
- Case: Setting Partial Cluster Keys
- Case: Converting from NOT IN to NOT EXISTS
-
GaussDB(DWS) System Catalogs and Views
- Overview of System Catalogs and System Views
-
System Catalogs
- GS_BLOCKLIST_QUERY
- GS_BLOCKLIST_SQL
- GS_OBSSCANINFO
- GS_RESPOOL_RESOURCE_HISTORY
- GS_WLM_INSTANCE_HISTORY
- GS_WLM_OPERATOR_INFO
- GS_WLM_SESSION_INFO
- GS_WLM_USER_RESOURCE_HISTORY
- PG_AGGREGATE
- PG_AM
- PG_AMOP
- PG_AMPROC
- PG_ATTRDEF
- PG_ATTRIBUTE
- PG_AUTHID
- PG_AUTH_HISTORY
- PG_AUTH_MEMBERS
- PG_BLOCKLISTS
- PG_CAST
- PG_CLASS
- PG_COLLATION
- PG_CONSTRAINT
- PG_CONVERSION
- PG_DATABASE
- PG_DB_ROLE_SETTING
- PG_DEFAULT_ACL
- PG_DEPEND
- PG_DESCRIPTION
- PG_ENUM
- PG_EXCEPT_RULE
- PG_EXTENSION
- PG_EXTENSION_DATA_SOURCE
- PG_FINE_DR_INFO
- PG_FOREIGN_DATA_WRAPPER
- PG_FOREIGN_SERVER
- PG_FOREIGN_TABLE
- PG_INDEX
- PG_INHERITS
- PG_JOB_INFO
- PG_JOBS
- PG_LANGUAGE
- PG_LARGEOBJECT
- PG_LARGEOBJECT_METADATA
- PG_MATVIEW
- PG_NAMESPACE
- PG_OBJECT
- PG_OBSSCANINFO
- PG_OPCLASS
- PG_OPERATOR
- PG_OPFAMILY
- PG_PARTITION
- PG_PLTEMPLATE
- PG_PROC
- PG_PUBLICATION
- PG_PUBLICATION_NAMESPACE
- PG_PUBLICATION_REL
- PG_RANGE
- PG_REDACTION_COLUMN
- PG_REDACTION_POLICY
- PG_RELFILENODE_SIZE
- PG_RLSPOLICY
- PG_RESOURCE_POOL
- PG_REWRITE
- PG_SECLABEL
- PG_SHDEPEND
- PG_SHDESCRIPTION
- PG_SHSECLABEL
- PG_STATISTIC
- PG_STATISTIC_EXT
- PG_STAT_OBJECT
- PG_SUBSCRIPTION
- PG_SYNONYM
- PG_TABLESPACE
- PG_TRIGGER
- PG_TS_CONFIG
- PG_TS_CONFIG_MAP
- PG_TS_DICT
- PG_TS_PARSER
- PG_TS_TEMPLATE
- PG_TYPE
- PG_USER_MAPPING
- PG_USER_STATUS
- PG_WORKLOAD_ACTION
- PGXC_CLASS
- PGXC_GROUP
- PGXC_NODE
- PLAN_TABLE_DATA
- SNAPSHOT
- TABLES_SNAP_TIMESTAMP
- System Catalogs for Performance View Snapshot
-
System Views
- ALL_ALL_TABLES
- ALL_CONSTRAINTS
- ALL_CONS_COLUMNS
- ALL_COL_COMMENTS
- ALL_DEPENDENCIES
- ALL_IND_COLUMNS
- ALL_IND_EXPRESSIONS
- ALL_INDEXES
- ALL_OBJECTS
- ALL_PROCEDURES
- ALL_SEQUENCES
- ALL_SOURCE
- ALL_SYNONYMS
- ALL_TAB_COLUMNS
- ALL_TAB_COMMENTS
- ALL_TABLES
- ALL_USERS
- ALL_VIEWS
- DBA_DATA_FILES
- DBA_USERS
- DBA_COL_COMMENTS
- DBA_CONSTRAINTS
- DBA_CONS_COLUMNS
- DBA_IND_COLUMNS
- DBA_IND_EXPRESSIONS
- DBA_IND_PARTITIONS
- DBA_INDEXES
- DBA_OBJECTS
- DBA_PART_INDEXES
- DBA_PART_TABLES
- DBA_PROCEDURES
- DBA_SEQUENCES
- DBA_SOURCE
- DBA_SYNONYMS
- DBA_TAB_COLUMNS
- DBA_TAB_COMMENTS
- DBA_TAB_PARTITIONS
- DBA_TABLES
- DBA_TABLESPACES
- DBA_TRIGGERS
- DBA_VIEWS
- DUAL
- GET_ALL_TSC_INFO
- GET_TSC_INFO
- GLOBAL_COLUMN_TABLE_IO_STAT
- GLOBAL_REDO_STAT
- GLOBAL_REL_IOSTAT
- GLOBAL_ROW_TABLE_IO_STAT
- GLOBAL_STAT_DATABASE
- GLOBAL_TABLE_CHANGE_STAT
- GLOBAL_TABLE_STAT
- GLOBAL_WORKLOAD_SQL_COUNT
- GLOBAL_WORKLOAD_SQL_ELAPSE_TIME
- GLOBAL_WORKLOAD_TRANSACTION
- GS_ALL_CONTROL_GROUP_INFO
- GS_BLOCKLIST_QUERY
- GS_BLOCKLIST_SQL
- GS_CLUSTER_RESOURCE_INFO
- GS_COLUMN_TABLE_IO_STAT
- GS_OBS_READ_TRAFFIC
- GS_OBS_WRITE_TRAFFIC
- GS_INSTR_UNIQUE_SQL
- GS_NODE_STAT_RESET_TIME
- GS_OBS_LATENCY
- GS_QUERY_MONITOR
- GS_QUERY_RESOURCE_INFO
- GS_REL_IOSTAT
- GS_RESPOOL_RUNTIME_INFO
- GS_RESPOOL_RESOURCE_INFO
- GS_RESPOOL_MONITOR
- GS_ROW_TABLE_IO_STAT
- GS_SESSION_CPU_STATISTICS
- GS_SESSION_MEMORY_STATISTICS
- GS_SQL_COUNT
- GS_STAT_DB_CU
- GS_STAT_SESSION_CU
- GS_TABLE_CHANGE_STAT
- GS_TABLE_STAT
- GS_TOTAL_NODEGROUP_MEMORY_DETAIL
- GS_USER_MONITOR
- GS_USER_TRANSACTION
- GS_VIEW_DEPENDENCY
- GS_VIEW_DEPENDENCY_PATH
- GS_VIEW_INVALID
- GS_WAIT_EVENTS
- GS_WLM_OPERAROR_INFO
- GS_WLM_OPERATOR_HISTORY
- GS_WLM_OPERATOR_STATISTICS
- GS_WLM_SESSION_INFO
- GS_WLM_SESSION_HISTORY
- GS_WLM_SESSION_STATISTICS
- GS_WLM_SQL_ALLOW
- GS_WORKLOAD_SQL_COUNT
- GS_WORKLOAD_SQL_ELAPSE_TIME
- GS_WORKLOAD_TRANSACTION
- MPP_TABLES
- PG_AVAILABLE_EXTENSION_VERSIONS
- PG_AVAILABLE_EXTENSIONS
- PG_BULKLOAD_STATISTICS
- PG_COMM_CLIENT_INFO
- PG_COMM_DELAY
- PG_COMM_STATUS
- PG_COMM_RECV_STREAM
- PG_COMM_SEND_STREAM
- PG_COMM_QUERY_SPEED
- PG_CONTROL_GROUP_CONFIG
- PG_CURSORS
- PG_EXT_STATS
- PG_GET_INVALID_BACKENDS
- PG_GET_SENDERS_CATCHUP_TIME
- PG_GROUP
- PG_INDEXES
- PG_JOB
- PG_JOB_PROC
- PG_JOB_SINGLE
- PG_LIFECYCLE_DATA_DISTRIBUTE
- PG_LOCKS
- PG_LWLOCKS
- PG_NODE_ENV
- PG_OS_THREADS
- PG_POOLER_STATUS
- PG_PREPARED_STATEMENTS
- PG_PREPARED_XACTS
- PG_PUBLICATION_TABLES
- PG_QUERYBAND_ACTION
- PG_REPLICATION_SLOTS
- PG_ROLES
- PG_RULES
- PG_RUNNING_XACTS
- PG_SECLABELS
- PG_SEQUENCES
- PG_SESSION_WLMSTAT
- PG_SESSION_IOSTAT
- PG_SETTINGS
- PG_SHADOW
- PG_SHARED_MEMORY_DETAIL
- PG_STATS
- PG_STAT_ACTIVITY
- PG_STAT_ALL_INDEXES
- PG_STAT_ALL_TABLES
- PG_STAT_BAD_BLOCK
- PG_STAT_BGWRITER
- PG_STAT_DATABASE
- PG_STAT_DATABASE_CONFLICTS
- PG_STAT_GET_MEM_MBYTES_RESERVED
- PG_STAT_USER_FUNCTIONS
- PG_STAT_USER_INDEXES
- PG_STAT_USER_TABLES
- PG_STAT_REPLICATION
- PG_STAT_SYS_INDEXES
- PG_STAT_SYS_TABLES
- PG_STAT_XACT_ALL_TABLES
- PG_STAT_XACT_SYS_TABLES
- PG_STAT_XACT_USER_FUNCTIONS
- PG_STAT_XACT_USER_TABLES
- PG_STATIO_ALL_INDEXES
- PG_STATIO_ALL_SEQUENCES
- PG_STATIO_ALL_TABLES
- PG_STATIO_SYS_INDEXES
- PG_STATIO_SYS_SEQUENCES
- PG_STATIO_SYS_TABLES
- PG_STATIO_USER_INDEXES
- PG_STATIO_USER_SEQUENCES
- PG_STATIO_USER_TABLES
- PG_THREAD_WAIT_STATUS
- PG_TABLES
- PG_TDE_INFO
- PG_TIMEZONE_ABBREVS
- PG_TIMEZONE_NAMES
- PG_TOTAL_MEMORY_DETAIL
- PG_TOTAL_SCHEMA_INFO
- PG_TOTAL_USER_RESOURCE_INFO
- PG_USER
- PG_USER_MAPPINGS
- PG_VIEWS
- PG_WLM_STATISTICS
- PGXC_AIO_RESOURCE_POOL_STATS
- PGXC_BULKLOAD_PROGRESS
- PGXC_BULKLOAD_INFO
- PGXC_BULKLOAD_STATISTICS
- PGXC_COLUMN_TABLE_IO_STAT
- PGXC_COMM_CLIENT_INFO
- PGXC_COMM_DELAY
- PGXC_COMM_RECV_STREAM
- PGXC_COMM_SEND_STREAM
- PGXC_COMM_STATUS
- PGXC_COMM_QUERY_SPEED
- PGXC_DEADLOCK
- PGXC_DISK_CACHE_STATS
- PGXC_DISK_CACHE_ALL_STATS
- PGXC_DISK_CACHE_PATH_INFO
- PGXC_GET_STAT_ALL_TABLES
- PGXC_GET_STAT_ALL_PARTITIONS
- PGXC_GET_TABLE_SKEWNESS
- PGXC_GTM_SNAPSHOT_STATUS
- PGXC_INSTANCE_TIME
- PGXC_LOCKWAIT_DETAIL
- PGXC_INSTR_UNIQUE_SQL
- PGXC_LOCK_CONFLICTS
- PGXC_LWLOCKS
- PGXC_MEMORY_DEBUG_INFO
- PGXC_NODE_ENV
- PGXC_NODE_STAT_RESET_TIME
- PGXC_OBS_IO_SCHEDULER_STATS
- PGXC_OBS_IO_SCHEDULER_PERIODIC_STATS
- PGXC_OS_RUN_INFO
- PGXC_OS_THREADS
- PGXC_POOLER_STATUS
- PGXC_PREPARED_XACTS
- PGXC_REDO_STAT
- PGXC_REL_IOSTAT
- PGXC_REPLICATION_SLOTS
- PGXC_RESPOOL_RUNTIME_INFO
- PGXC_RESPOOL_RESOURCE_INFO
- PGXC_RESPOOL_RESOURCE_HISTORY
- PGXC_ROW_TABLE_IO_STAT
- PGXC_RUNNING_XACTS
- PGXC_SETTINGS
- PGXC_SESSION_WLMSTAT
- PGXC_STAT_ACTIVITY
- PGXC_STAT_BAD_BLOCK
- PGXC_STAT_BGWRITER
- PGXC_STAT_DATABASE
- PGXC_STAT_OBJECT
- PGXC_STAT_REPLICATION
- PGXC_STAT_TABLE_DIRTY
- PGXC_STAT_WAL
- PGXC_SQL_COUNT
- PGXC_TABLE_CHANGE_STAT
- PGXC_TABLE_STAT
- PGXC_THREAD_WAIT_STATUS
- PGXC_TOTAL_MEMORY_DETAIL
- PGXC_TOTAL_SCHEMA_INFO
- PGXC_TOTAL_SCHEMA_INFO_ANALYZE
- PGXC_TOTAL_USER_RESOURCE_INFO
- PGXC_USER_TRANSACTION
- PGXC_VARIABLE_INFO
- PGXC_WAIT_DETAIL
- PGXC_WAIT_EVENTS
- PGXC_WLM_OPERATOR_HISTORY
- PGXC_WLM_OPERATOR_INFO
- PGXC_WLM_OPERATOR_STATISTICS
- PGXC_WLM_SESSION_INFO
- PGXC_WLM_SESSION_HISTORY
- PGXC_WLM_SESSION_STATISTICS
- PGXC_WLM_TABLE_DISTRIBUTION_SKEWNESS
- PGXC_WLM_USER_RESOURCE_HISTORY
- PGXC_WLM_WORKLOAD_RECORDS
- PGXC_WORKLOAD_SQL_COUNT
- PGXC_WORKLOAD_SQL_ELAPSE_TIME
- PGXC_WORKLOAD_TRANSACTION
- PLAN_TABLE
- PV_FILE_STAT
- PV_INSTANCE_TIME
- PV_MATVIEW_DETAIL
- PV_OS_RUN_INFO
- PV_SESSION_MEMORY
- PV_SESSION_MEMORY_DETAIL
- PV_SESSION_STAT
- PV_SESSION_TIME
- PV_TOTAL_MEMORY_DETAIL
- PV_REDO_STAT
- PV_RUNTIME_ATTSTATS
- PV_RUNTIME_RELSTATS
- REDACTION_COLUMNS
- REDACTION_POLICIES
- REMOTE_TABLE_STAT
- SHOW_TSC_INFO
- SHOW_ALL_TSC_INFO
- USER_COL_COMMENTS
- USER_CONSTRAINTS
- USER_CONS_COLUMNS
- USER_INDEXES
- USER_IND_COLUMNS
- USER_IND_EXPRESSIONS
- USER_IND_PARTITIONS
- USER_JOBS
- USER_OBJECTS
- USER_PART_INDEXES
- USER_PART_TABLES
- USER_PROCEDURES
- USER_SEQUENCES
- USER_SOURCE
- USER_SYNONYMS
- USER_TAB_COLUMNS
- USER_TAB_COMMENTS
- USER_TAB_PARTITIONS
- USER_TABLES
- USER_TRIGGERS
- USER_VIEWS
- V$SESSION
- V$SESSION_LONGOPS
-
GUC Parameters of the GaussDB(DWS) Database
- Viewing GUC Parameters
- Configuring GUC Parameters
- GUC Parameter Usage
- Connection and Authentication
- Resource Consumption
- Parallel Data Import
- Write Ahead Logs
- HA Replication
- Query Planning
- Error Reporting and Logging
- Alarm Detection
- Statistics During the Database Running
- Resource Management
- Automatic Cleanup
- Default Settings of Client Connection
- Lock Management
- Version and Platform Compatibility
- Fault Tolerance
- Connection Pool Parameters
- Cluster Transaction Parameters
- Developer Operations
- Auditing
- Transaction Monitoring
- GTM Parameters
- Miscellaneous Parameters
- GaussDB(DWS) Developer Terms
-
Standard data warehouse (8.1.3.x)
- Before You Start
-
GaussDB(DWS) Development Design Specifications
- Overview
- GaussDB(DWS) Connection Management Specifications
- GaussDB(DWS) Object Design Specifications
- GaussDB(DWS) SQL Statement Development Specifications
- GaussDB(DWS) Stored Procedure Development Specifications
- Detailed Design Rules for GaussDB(DWS) Objects
-
Creating and Managing GaussDB(DWS) Database Objects
- Creating and Managing GaussDB(DWS) Databases
- Creating and Managing GaussDB(DWS) Schemas
- Selecting a GaussDB(DWS) Table Storage Model
- Creating and Managing GaussDB(DWS) Tables
- Creating and Managing GaussDB(DWS) Partitioned Tables
- Creating and Managing GaussDB(DWS) Indexes
- Creating and Using GaussDB(DWS) Sequences
- Creating and Managing GaussDB(DWS) Views
- Creating and Managing GaussDB(DWS) Scheduled Tasks
- Viewing GaussDB(DWS) System Catalogs
- Syntax Compatibility Differences Among Oracle, Teradata, and MySQL
- GaussDB(DWS) Database Security Management
- GaussDB(DWS) Data Query
- GaussDB(DWS) Sorting Rules
- GaussDB(DWS) User-Defined Functions
-
GaussDB(DWS) Stored Procedure
- Overview
- Converting Data Types in GaussDB(DWS) Stored Procedures
- GaussDB(DWS) Stored Procedure Array and Record
- GaussDB(DWS) Stored Procedure Declaration Syntax
- Basic Statements of GaussDB(DWS) Stored Procedures
- Dynamic Statements of GaussDB(DWS) Stored Procedures
- GaussDB(DWS) Stored Procedure Control Statements
- Other Statements in a GaussDB(DWS) Stored Procedure
- GaussDB(DWS) Stored Procedure Cursor
- GaussDB(DWS) Stored Procedure Advanced Package
- GaussDB(DWS) Stored Procedure Debugging
- Using PostGIS Extension
- Using JDBC or ODBC for GaussDB(DWS) Secondary Development
- GaussDB(DWS) Resource Monitoring
-
GaussDB(DWS) Performance Tuning
- Overview
- Performance Diagnosis
- System Optimization
-
SQL Tuning
- SQL Query Execution Process
- SQL Execution Plan
- Execution Plan Operator
- SQL Tuning Process
- Updating Statistics
- Reviewing and Modifying a Table Definition
- Advanced SQL Tuning
- Hint-based Tuning
- Routinely Maintaining Tables
- Routinely Recreating an Index
- Automatic Retry upon SQL Statement Execution Errors
- query_band Load Identification
-
SQL Tuning Examples
- Case: Selecting an Appropriate Distribution Column
- Case: Creating an Appropriate Index
- Case: Adding NOT NULL for JOIN Columns
- Case: Pushing Down Sort Operations to DNs
- Case: Configuring cost_param for Better Query Performance
- Case: Adjusting the Partial Clustering Key
- Case: Adjusting the Table Storage Mode in a Medium Table
- Case: Reconstructing Partition Tables
- Case: Adjusting the GUC Parameter best_agg_plan
- Case: Rewriting SQL Statements and Eliminating Prune Interference
- Case: Rewriting SQL Statements and Deleting in-clause
- Case: Setting Partial Cluster Keys
- Case: Converting from NOT IN to NOT EXISTS
-
GaussDB(DWS) System Catalogs and Views
- Overview of System Catalogs and System Views
-
System Catalogs
- GS_OBSSCANINFO
- GS_RESPOOL_RESOURCE_HISTORY
- GS_WLM_INSTANCE_HISTORY
- GS_WLM_OPERATOR_INFO
- GS_WLM_SESSION_INFO
- GS_WLM_USER_RESOURCE_HISTORY
- PG_AGGREGATE
- PG_AM
- PG_AMOP
- PG_AMPROC
- PG_ATTRDEF
- PG_ATTRIBUTE
- PG_AUTHID
- PG_AUTH_HISTORY
- PG_AUTH_MEMBERS
- PG_CAST
- PG_CLASS
- PG_COLLATION
- PG_CONSTRAINT
- PG_CONVERSION
- PG_DATABASE
- PG_DB_ROLE_SETTING
- PG_DEFAULT_ACL
- PG_DEPEND
- PG_DESCRIPTION
- PG_ENUM
- PG_EXTENSION
- PG_EXTENSION_DATA_SOURCE
- PG_FOREIGN_DATA_WRAPPER
- PG_FOREIGN_SERVER
- PG_FOREIGN_TABLE
- PG_INDEX
- PG_INHERITS
- PG_JOBS
- PG_LANGUAGE
- PG_LARGEOBJECT
- PG_LARGEOBJECT_METADATA
- PG_NAMESPACE
- PG_OBJECT
- PG_OBSSCANINFO
- PG_OPCLASS
- PG_OPERATOR
- PG_OPFAMILY
- PG_PARTITION
- PG_PLTEMPLATE
- PG_PROC
- PG_RANGE
- PG_REDACTION_COLUMN
- PG_REDACTION_POLICY
- PG_RELFILENODE_SIZE
- PG_RLSPOLICY
- PG_RESOURCE_POOL
- PG_REWRITE
- PG_SECLABEL
- PG_SHDEPEND
- PG_SHDESCRIPTION
- PG_SHSECLABEL
- PG_STATISTIC
- PG_STATISTIC_EXT
- PG_SYNONYM
- PG_TABLESPACE
- PG_TRIGGER
- PG_TS_CONFIG
- PG_TS_CONFIG_MAP
- PG_TS_DICT
- PG_TS_PARSER
- PG_TS_TEMPLATE
- PG_TYPE
- PG_USER_MAPPING
- PG_USER_STATUS
- PG_WORKLOAD_ACTION
- PGXC_CLASS
- PGXC_GROUP
- PGXC_NODE
- PLAN_TABLE_DATA
- SNAPSHOT
- TABLES_SNAP_TIMESTAMP
- System Catalogs for Performance View Snapshot
-
System Views
- ALL_ALL_TABLES
- ALL_CONSTRAINTS
- ALL_CONS_COLUMNS
- ALL_COL_COMMENTS
- ALL_DEPENDENCIES
- ALL_IND_COLUMNS
- ALL_IND_EXPRESSIONS
- ALL_INDEXES
- ALL_OBJECTS
- ALL_PROCEDURES
- ALL_SEQUENCES
- ALL_SOURCE
- ALL_SYNONYMS
- ALL_TAB_COLUMNS
- ALL_TAB_COMMENTS
- ALL_TABLES
- ALL_USERS
- ALL_VIEWS
- DBA_DATA_FILES
- DBA_USERS
- DBA_COL_COMMENTS
- DBA_CONSTRAINTS
- DBA_CONS_COLUMNS
- DBA_IND_COLUMNS
- DBA_IND_EXPRESSIONS
- DBA_IND_PARTITIONS
- DBA_INDEXES
- DBA_OBJECTS
- DBA_PART_INDEXES
- DBA_PART_TABLES
- DBA_PROCEDURES
- DBA_SEQUENCES
- DBA_SOURCE
- DBA_SYNONYMS
- DBA_TAB_COLUMNS
- DBA_TAB_COMMENTS
- DBA_TAB_PARTITIONS
- DBA_TABLES
- DBA_TABLESPACES
- DBA_TRIGGERS
- DBA_VIEWS
- DUAL
- GLOBAL_COLUMN_TABLE_IO_STAT
- GLOBAL_REDO_STAT
- GLOBAL_REL_IOSTAT
- GLOBAL_ROW_TABLE_IO_STAT
- GLOBAL_STAT_DATABASE
- GLOBAL_TABLE_CHANGE_STAT
- GLOBAL_TABLE_STAT
- GLOBAL_WORKLOAD_SQL_COUNT
- GLOBAL_WORKLOAD_SQL_ELAPSE_TIME
- GLOBAL_WORKLOAD_TRANSACTION
- GS_ALL_CONTROL_GROUP_INFO
- GS_CLUSTER_RESOURCE_INFO
- GS_COLUMN_TABLE_IO_STAT
- GS_INSTR_UNIQUE_SQL
- GS_NODE_STAT_RESET_TIME
- GS_REL_IOSTAT
- GS_RESPOOL_RUNTIME_INFO
- GS_RESPOOL_RESOURCE_INFO
- GS_ROW_TABLE_IO_STAT
- GS_SESSION_CPU_STATISTICS
- GS_SESSION_MEMORY_STATISTICS
- GS_SQL_COUNT
- GS_STAT_DB_CU
- GS_STAT_SESSION_CU
- GS_TABLE_CHANGE_STAT
- GS_TABLE_STAT
- GS_TOTAL_NODEGROUP_MEMORY_DETAIL
- GS_USER_TRANSACTION
- GS_VIEW_DEPENDENCY
- GS_VIEW_DEPENDENCY_PATH
- GS_VIEW_INVALID
- GS_WAIT_EVENTS
- GS_WLM_OPERAROR_INFO
- GS_WLM_OPERATOR_HISTORY
- GS_WLM_OPERATOR_STATISTICS
- GS_WLM_SESSION_INFO
- GS_WLM_SESSION_HISTORY
- GS_WLM_SESSION_STATISTICS
- GS_WLM_SQL_ALLOW
- GS_WORKLOAD_SQL_COUNT
- GS_WORKLOAD_SQL_ELAPSE_TIME
- GS_WORKLOAD_TRANSACTION
- MPP_TABLES
- PG_AVAILABLE_EXTENSION_VERSIONS
- PG_AVAILABLE_EXTENSIONS
- PG_BULKLOAD_STATISTICS
- PG_COMM_CLIENT_INFO
- PG_COMM_DELAY
- PG_COMM_STATUS
- PG_COMM_RECV_STREAM
- PG_COMM_SEND_STREAM
- PG_COMM_QUERY_SPEED
- PG_CONTROL_GROUP_CONFIG
- PG_CURSORS
- PG_EXT_STATS
- PG_GET_INVALID_BACKENDS
- PG_GET_SENDERS_CATCHUP_TIME
- PG_GROUP
- PG_INDEXES
- PG_JOB
- PG_JOB_PROC
- PG_JOB_SINGLE
- PG_LIFECYCLE_DATA_DISTRIBUTE
- PG_LOCKS
- PG_NODE_ENV
- PG_OS_THREADS
- PG_POOLER_STATUS
- PG_PREPARED_STATEMENTS
- PG_PREPARED_XACTS
- PG_QUERYBAND_ACTION
- PG_REPLICATION_SLOTS
- PG_ROLES
- PG_RULES
- PG_RUNNING_XACTS
- PG_SECLABELS
- PG_SESSION_WLMSTAT
- PG_SESSION_IOSTAT
- PG_SETTINGS
- PG_SHADOW
- PG_SHARED_MEMORY_DETAIL
- PG_STATS
- PG_STAT_ACTIVITY
- PG_STAT_ALL_INDEXES
- PG_STAT_ALL_TABLES
- PG_STAT_BAD_BLOCK
- PG_STAT_BGWRITER
- PG_STAT_DATABASE
- PG_STAT_DATABASE_CONFLICTS
- PG_STAT_GET_MEM_MBYTES_RESERVED
- PG_STAT_USER_FUNCTIONS
- PG_STAT_USER_INDEXES
- PG_STAT_USER_TABLES
- PG_STAT_REPLICATION
- PG_STAT_SYS_INDEXES
- PG_STAT_SYS_TABLES
- PG_STAT_XACT_ALL_TABLES
- PG_STAT_XACT_SYS_TABLES
- PG_STAT_XACT_USER_FUNCTIONS
- PG_STAT_XACT_USER_TABLES
- PG_STATIO_ALL_INDEXES
- PG_STATIO_ALL_SEQUENCES
- PG_STATIO_ALL_TABLES
- PG_STATIO_SYS_INDEXES
- PG_STATIO_SYS_SEQUENCES
- PG_STATIO_SYS_TABLES
- PG_STATIO_USER_INDEXES
- PG_STATIO_USER_SEQUENCES
- PG_STATIO_USER_TABLES
- PG_THREAD_WAIT_STATUS
- PG_TABLES
- PG_TDE_INFO
- PG_TIMEZONE_ABBREVS
- PG_TIMEZONE_NAMES
- PG_TOTAL_MEMORY_DETAIL
- PG_TOTAL_SCHEMA_INFO
- PG_TOTAL_USER_RESOURCE_INFO
- PG_USER
- PG_USER_MAPPINGS
- PG_VIEWS
- PG_WLM_STATISTICS
- PGXC_BULKLOAD_PROGRESS
- PGXC_BULKLOAD_STATISTICS
- PGXC_COLUMN_TABLE_IO_STAT
- PGXC_COMM_CLIENT_INFO
- PGXC_COMM_DELAY
- PGXC_COMM_RECV_STREAM
- PGXC_COMM_SEND_STREAM
- PGXC_COMM_STATUS
- PGXC_COMM_QUERY_SPEED
- PGXC_DEADLOCK
- PGXC_GET_STAT_ALL_TABLES
- PGXC_GET_STAT_ALL_PARTITIONS
- PGXC_GET_TABLE_SKEWNESS
- PGXC_GTM_SNAPSHOT_STATUS
- PGXC_INSTANCE_TIME
- PGXC_LOCKWAIT_DETAIL
- PGXC_INSTR_UNIQUE_SQL
- PGXC_LOCK_CONFLICTS
- PGXC_NODE_ENV
- PGXC_NODE_STAT_RESET_TIME
- PGXC_OS_RUN_INFO
- PGXC_OS_THREADS
- PGXC_PREPARED_XACTS
- PGXC_REDO_STAT
- PGXC_REL_IOSTAT
- PGXC_REPLICATION_SLOTS
- PGXC_RESPOOL_RUNTIME_INFO
- PGXC_RESPOOL_RESOURCE_INFO
- PGXC_RESPOOL_RESOURCE_HISTORY
- PGXC_ROW_TABLE_IO_STAT
- PGXC_RUNNING_XACTS
- PGXC_SETTINGS
- PGXC_SESSION_WLMSTAT
- PGXC_STAT_ACTIVITY
- PGXC_STAT_BAD_BLOCK
- PGXC_STAT_BGWRITER
- PGXC_STAT_DATABASE
- PGXC_STAT_REPLICATION
- PGXC_STAT_TABLE_DIRTY
- PGXC_SQL_COUNT
- PGXC_TABLE_CHANGE_STAT
- PGXC_TABLE_STAT
- PGXC_THREAD_WAIT_STATUS
- PGXC_TOTAL_MEMORY_DETAIL
- PGXC_TOTAL_SCHEMA_INFO
- PGXC_TOTAL_SCHEMA_INFO_ANALYZE
- PGXC_USER_TRANSACTION
- PGXC_VARIABLE_INFO
- PGXC_WAIT_DETAIL
- PGXC_WAIT_EVENTS
- PGXC_WLM_OPERATOR_HISTORY
- PGXC_WLM_OPERATOR_INFO
- PGXC_WLM_OPERATOR_STATISTICS
- PGXC_WLM_SESSION_INFO
- PGXC_WLM_SESSION_HISTORY
- PGXC_WLM_SESSION_STATISTICS
- PGXC_WLM_WORKLOAD_RECORDS
- PGXC_WORKLOAD_SQL_COUNT
- PGXC_WORKLOAD_SQL_ELAPSE_TIME
- PGXC_WORKLOAD_TRANSACTION
- PLAN_TABLE
- PV_FILE_STAT
- PV_INSTANCE_TIME
- PV_OS_RUN_INFO
- PV_SESSION_MEMORY
- PV_SESSION_MEMORY_DETAIL
- PV_SESSION_STAT
- PV_SESSION_TIME
- PV_TOTAL_MEMORY_DETAIL
- PV_REDO_STAT
- REDACTION_COLUMNS
- REDACTION_POLICIES
- REMOTE_TABLE_STAT
- USER_COL_COMMENTS
- USER_CONSTRAINTS
- USER_CONS_COLUMNS
- USER_INDEXES
- USER_IND_COLUMNS
- USER_IND_EXPRESSIONS
- USER_IND_PARTITIONS
- USER_JOBS
- USER_OBJECTS
- USER_PART_INDEXES
- USER_PART_TABLES
- USER_PROCEDURES
- USER_SEQUENCES
- USER_SOURCE
- USER_SYNONYMS
- USER_TAB_COLUMNS
- USER_TAB_COMMENTS
- USER_TAB_PARTITIONS
- USER_TABLES
- USER_TRIGGERS
- USER_VIEWS
- V$SESSION
- V$SESSION_LONGOPS
-
GUC Parameters of the GaussDB(DWS) Database
- Viewing GUC Parameters
- Configuring GUC Parameters
- GUC Parameter Usage
- Connection and Authentication
- Resource Consumption
- Parallel Data Import
- Write Ahead Logs
- HA Replication
- Query Planning
- Error Reporting and Logging
- Alarm Detection
- Statistics During the Database Running
- Resource Management
- Automatic Cleanup
- Default Settings of Client Connection
- Lock Management
- Version and Platform Compatibility
- Fault Tolerance
- Connection Pool Parameters
- Cluster Transaction Parameters
- Developer Operations
- Auditing
- Transaction Monitoring
- GTM Parameters
- Miscellaneous Parameters
- GaussDB(DWS) Developer Terms
- Hybrid Data Warehouse (9.1.0.x)
- Hybrid Data Warehouse (8.1.3.x)
- Historical Versions
-
Standard data warehouse (9.1.0.x)
-
SQL Syntax Reference
-
SQL Syntax Reference (9.1.0.x)
- GaussDB(DWS) SQL Overview
- Differences Between GaussDB(DWS) and PostgreSQL
- Keyword
-
Data Types
- Numeric Types
- Monetary Types
- Boolean Type
- Character Types
- Binary Data Types
- Date/Time Types
- Geometric Types
- Array
- Enumeration Type
- Network Address Types
- Bit String Types
- Text Search Types
- UUID Type
- JSON Types
- RoaringBitmap
- HLL Data Types
- Object Identifier Types
- Pseudo-Types
- Range Types
- Composite Types
- Data Types Supported by Column-Store Tables
- XML
- Constant and Macro
-
Functions and Operators
- Character Processing Functions and Operators
- Binary String Functions and Operators
- Bit String Functions and Operators
- Numeric Functions and Operators
- Date and Time Processing Functions and Operators
- SEQUENCE Functions
- Array Functions and Operators
- Logical Operators
- Comparison Operators
- Pattern Matching Operators
- Aggregate Functions
- Window Functions
- Type Conversion Functions
- JSON/JSONB Functions and Operators
- Security Functions
- Conditional Expression Functions
- Range Functions and Operators
- Data Redaction Functions
- Bitmap Functions and Operators
- UUID Functions
- Text Search Functions and Operators
- HLL Functions and Operators
- Set Returning Functions
- Geometric Functions and Operators
- Network Address Functions and Operators
- System Information Functions
- System Administration Functions
- Backup and Restoration Control Functions
- Database Object Functions
- Residual File Management Functions
- Statistics Information Functions
- Trigger Functions
- XML Functions
- Call Stack Recording Functions
- Hudi System Functions
- Funnel and Retention Functions
- EXTERNAL SCHEMA System Functions
- Storage-Compute Decoupling Functions
- Expressions
- Type Conversion
- Full Text Search
- System Operation
- Transaction Management
-
DDL Syntax
- DDL Syntax Overview
- ALTER BLOCK RULE
- ALTER DATABASE
- ALTER EXCEPT RULE
- ALTER EXTERNAL SCHEMA
- ALTER FOREIGN TABLE (GDS Import and Export)
- ALTER FOREIGN TABLE (for HDFS or OBS)
- ALTER FOREIGN TABLE (SQL on other GaussDB(DWS))
- ALTER FUNCTION
- ALTER GROUP
- ALTER INDEX
- ALTER LARGE OBJECT
- ALTER MATERIALIZED VIEW
- ALTER PUBLICATION
- ALTER REDACTION POLICY
- ALTER RESOURCE POOL
- ALTER ROLE
- ALTER SUBSCRIPTION
- ALTER ROW LEVEL SECURITY POLICY
- ALTER SCHEMA
- ALTER SEQUENCE
- ALTER SERVER
- ALTER SESSION
- ALTER SYNONYM
- ALTER SYSTEM KILL SESSION
- ALTER TABLE
- ALTER TABLE PARTITION
- ALTER TEXT SEARCH CONFIGURATION
- ALTER TEXT SEARCH DICTIONARY
- ALTER TRIGGER
- ALTER TYPE
- ALTER USER
- ALTER VIEW
- CLEAN CONNECTION
- CLOSE
- CLUSTER
- COMMENT
- CREATE BARRIER
- CREATE BLOCK RULE
- CREATE DATABASE
- CREATE EXCEPT RULE
- CREATE EXTERNAL SCHEMA
- CREATE FOREIGN TABLE (for GDS Import and Export)
- CREATE FOREIGN TABLE (SQL on OBS or Hadoop)
- CREATE FOREIGN TABLE (for OBS Import and Export)
- CREATE FOREIGN TABLE (SQL on other GaussDB(DWS))
- CREATE FUNCTION
- CREATE GROUP
- CREATE INDEX
- CREATE MATERIALIZED VIEW
- CREATE PROCEDURE
- CREATE PUBLICATION
- CREATE REDACTION POLICY
- CREATE ROW LEVEL SECURITY POLICY
- CREATE RESOURCE POOL
- CREATE ROLE
- CREATE SCHEMA
- CREATE SEQUENCE
- CREATE SERVER
- CREATE SUBSCRIPTION
- CREATE SYNONYM
- CREATE TABLE
- CREATE TABLE AS
- CREATE TABLE PARTITION
- CREATE TEXT SEARCH CONFIGURATION
- CREATE TEXT SEARCH DICTIONARY
- CREATE TRIGGER
- CREATE TYPE
- CREATE USER
- CREATE VIEW
- CURSOR
- DISCARD
- DROP BLOCK RULE
- DROP DATABASE
- DROP EXCEPT RULE
- DROP FOREIGN TABLE
- DROP FUNCTION
- DROP GROUP
- DROP INDEX
- DROP MATERIALIZED VIEW
- DROP OWNED
- DROP PUBLICATION
- DROP REDACTION POLICY
- DROP ROW LEVEL SECURITY POLICY
- DROP PROCEDURE
- DROP RESOURCE POOL
- DROP ROLE
- DROP SCHEMA
- DROP SEQUENCE
- DROP SERVER
- DROP SUBSCRIPTION
- DROP SYNONYM
- DROP TABLE
- DROP TEXT SEARCH CONFIGURATION
- DROP TEXT SEARCH DICTIONARY
- DROP TRIGGER
- DROP TYPE
- DROP USER
- DROP VIEW
- FETCH
- MOVE
- REFRESH MATERIALIZED VIEW
- REINDEX
- RENAME TABLE
- RESET
- SET
- SET CONSTRAINTS
- SET ROLE
- SET SESSION AUTHORIZATION
- SHOW
- TRUNCATE
- VACUUM
- DML Syntax
- DCL Syntax
- DQL Syntax
- TCL Syntax
-
SQL Syntax Reference (8.1.3.x)
- GaussDB(DWS) SQL Overview
- Differences Between GaussDB(DWS) and PostgreSQL
- Keyword
-
Data Types
- Numeric Types
- Monetary Types
- Boolean Type
- Character Types
- Binary Data Types
- Date/Time Types
- Geometric Types
- Array
- Enumeration Type
- Network Address Types
- Bit String Types
- Text Search Types
- UUID Type
- JSON Types
- RoaringBitmap
- HLL Data Types
- Object Identifier Types
- Pseudo-Types
- Range Types
- Composite Types
- Data Types Supported by Column-Store Tables
- XML
- Constant and Macro
-
Functions and Operators
- Character Processing Functions and Operators
- Binary String Functions and Operators
- Bit String Functions and Operators
- Mathematical Functions and Operators
- Date and Time Processing Functions and Operators
- SEQUENCE Functions
- Array Functions and Operators
- Logical Operators
- Comparison Operators
- Pattern Matching Operators
- Aggregate Functions
- Window Functions
- Type Conversion Functions
- JSON/JSONB Functions and Operators
- Security Functions
- Conditional Expression Functions
- Range Functions and Operators
- Data Masking Functions
- Roaring Bitmap Functions and Operators
- UUID Functions
- Text Search Functions and Operators
- HLL Functions and Operators
- Set Returning Functions
- Geometric Functions and Operators
- Network Address Functions and Operators
- System Information Functions
- System Administration Functions
- Database Object Functions
- Residual File Management Functions
- Statistics Information Functions
- Trigger Functions
- XML Functions
- Call Stack Recording Functions
- Expressions
- Type Conversion
- Full Text Search
- System Operation
- Transaction Management
-
DDL Syntax
- DDL Syntax Overview
- ALTER DATABASE
- ALTER FOREIGN TABLE (GDS Import and Export)
- ALTER FOREIGN TABLE (for HDFS or OBS)
- ALTER FOREIGN TABLE (SQL on other GaussDB(DWS))
- ALTER FUNCTION
- ALTER GROUP
- ALTER INDEX
- ALTER LARGE OBJECT
- ALTER REDACTION POLICY
- ALTER RESOURCE POOL
- ALTER ROLE
- ALTER ROW LEVEL SECURITY POLICY
- ALTER SCHEMA
- ALTER SEQUENCE
- ALTER SERVER
- ALTER SESSION
- ALTER SYNONYM
- ALTER SYSTEM KILL SESSION
- ALTER TABLE
- ALTER TABLE PARTITION
- ALTER TEXT SEARCH CONFIGURATION
- ALTER TEXT SEARCH DICTIONARY
- ALTER TRIGGER
- ALTER TYPE
- ALTER USER
- ALTER VIEW
- CLEAN CONNECTION
- CLOSE
- CLUSTER
- COMMENT
- CREATE BARRIER
- CREATE DATABASE
- CREATE FOREIGN TABLE (for GDS Import and Export)
- CREATE FOREIGN TABLE (SQL on OBS or Hadoop)
- CREATE FOREIGN TABLE (for OBS Import and Export)
- CREATE FOREIGN TABLE (SQL on other GaussDB(DWS))
- CREATE FUNCTION
- CREATE GROUP
- CREATE INDEX
- CREATE REDACTION POLICY
- CREATE ROW LEVEL SECURITY POLICY
- CREATE PROCEDURE
- CREATE RESOURCE POOL
- CREATE ROLE
- CREATE SCHEMA
- CREATE SEQUENCE
- CREATE SERVER
- CREATE SYNONYM
- CREATE TABLE
- CREATE TABLE AS
- CREATE TABLE PARTITION
- CREATE TEXT SEARCH CONFIGURATION
- CREATE TEXT SEARCH DICTIONARY
- CREATE TRIGGER
- CREATE TYPE
- CREATE USER
- CREATE VIEW
- CURSOR
- DROP DATABASE
- DROP FOREIGN TABLE
- DROP FUNCTION
- DROP GROUP
- DROP INDEX
- DROP OWNED
- DROP REDACTION POLICY
- DROP ROW LEVEL SECURITY POLICY
- DROP PROCEDURE
- DROP RESOURCE POOL
- DROP ROLE
- DROP SCHEMA
- DROP SEQUENCE
- DROP SERVER
- DROP SYNONYM
- DROP TABLE
- DROP TEXT SEARCH CONFIGURATION
- DROP TEXT SEARCH DICTIONARY
- DROP TRIGGER
- DROP TYPE
- DROP USER
- DROP VIEW
- FETCH
- MOVE
- REINDEX
- RENAME TABLE
- RESET
- SET
- SET CONSTRAINTS
- SET ROLE
- SET SESSION AUTHORIZATION
- SHOW
- TRUNCATE
- VACUUM
- DML Syntax
- DCL Syntax
- DQL Syntax
- TCL Syntax
- Historical Versions
-
SQL Syntax Reference (9.1.0.x)
-
Performance Tuning
- Overview of Query Performance Optimization
- Query Execution Process
- SQL Execution Plan
-
SQL Optimization Guide
- Optimization Process
- Updating Statistics
- Reviewing and Modifying a Table Definition
- SQL Statement Rewriting Rules
- Typical SQL Optimization Methods
- Hint-based Tuning
- Routinely Maintaining Tables
- Routinely Recreating an Index
- Adjusting Key Parameters During SQL Tuning
- Configuring SMP
- Querying SQL Statements That Affect Performance Most
-
Optimization Cases
- Case: Selecting an Appropriate Distribution Column
- Case: Creating an Appropriate Index
- Case: Adding NOT NULL for JOIN Columns
- Case: Pushing Down Sort Operations to DNs
- Case: Configuring cost_param for Better Query Performance
- Case: Adjusting the Partial Clustering Key
- Case: Adjusting the Table Storage Mode in a Medium Table
- Case: Reconstructing Partition Tables
- Case: Adjusting the GUC Parameter best_agg_plan
- Case: Rewriting SQL Statements and Eliminating Prune Interference
- Case: Rewriting SQL Statements and Deleting in-clause
- Case: Setting Partial Cluster Keys
- Case: Converting from NOT IN to NOT EXISTS
- SQL Execution Troubleshooting
- query_band Load Identification
- Common Performance Parameter Optimization Design
-
Tool Guide
- Overview
- Downloading Related Tools
- gsql
-
Data Studio
- About Data Studio
- Downloading and Installing the Data Studio Client
- Configuring Data Studio
- Configuring SSL Connection
- Connection Management
- Database Management
-
SQL Terminal Management
- Opening Multiple SQL Terminal Tabs
- Managing the SQL Query Execution History
- Opening and Saving SQL Scripts
- Viewing Table Properties, PL/SQL Functions/Procedures on the SQL Terminal Page
- Terminating an Ongoing SQL Query
- Formatting of SQL Queries
- Selecting a DB Object in the SQL Terminal
- Viewing the Execution Plan and Costs
- Viewing the Query Execution Plan and Cost Graphically
- Working with SQL Terminals
- Exporting Query Results
- Managing SQL Terminal Connections
- Security Management
- Troubleshooting
- FAQs
- GDS
-
DSC
- About This Document
- Introduction to DSC
- Using DSC
-
Teradata Syntax Migration
- Supported Keywords and Features
- Constraints and Limitations
- Data Type
- Functions and Operators
- Migrating Tables
- Migrating Indexes
- Migrating Views
- COLLECT STATISTICS
- ACCESS LOCK
- DBC.COLUMNS
- DBC.TABLES
- DBC.INDICES
- SHOW STATS VALUES SEQUENCED
- COMMENT
- Data Manipulation Language (DML)
- Type Casting and Formatting
- BTEQ Utility Command
- Teradata Formats
- System Views
-
MySQL Syntax Migrating
- Supported Keywords and Features
- Data Types
- Functions and Expressions
-
Table (Optional Parameters and Operations)
- ALGORITHM
- ALTER TABLE RENAME
- AUTO_INCREMENT
- AVG_ROW_LENGTH
- BLOCK_SIZE
- CHARSET
- CHECKSUM
- CLUSTERED KEY
- COLLATE
- COMMENT
- CONNECTION
- DEFAULT
- DELAY_KEY_WRITE
- DISTRIBUTE BY
- DIRECTORY
- ENGINE
- FOREIGN_KEY_CHECKS
- IF NOT EXISTS
- INDEX_ALL
- INSERT_METHOD
- KEY_BLOCK_SIZE
- LOCK
- MAX_ROWS
- MIN_ROWS
- PACK_KEYS
- PARTITION BY
- PASSWORD
- ROW_FORMAT
- STATS_AUTO_RECALC
- STATS_PERSISTENT
- STATS_SAMPLE_PAGES
- UNION
- WITH AS
- CHANGE (Column Modification)
- CHECK Constraint
- DROP (Table Deletion)
- LIKE (Table Cloning)
- MODIFY (Modifying a Column)
- TRUNCATE (Table Deletion)
- ROUNDROBIN Table
- RENAME (Table Renaming)
- SET|DROP COLUMN DEFAULT VALUE
- Renaming a Column
- Row-Store/Column-Store Table Compression
- Adding/Deleting a Column
- Indexes
- Comment
- Databases
- Data Manipulation Language (DML)
- Transaction Management and Database Management
- SQL-Server Syntax Migration
-
Oracle Syntax Migration
- Schema Objects
- COMPRESS Phrase
- Bitmap Index
- Custom Tablespace
- Supplemental Log Data
- LONG RAW
- SYS_GUID
- DML
- Pseudo Columns
- OUTER JOIN
- OUTER QUERY (+)
- CONNECT BY
- System Functions
- PL/SQL
- PL/SQL Collections (Using User-Defined Types)
- PL/SQL Packages
- VARRAY
- Granting Execution Permissions
- Package Name List
- Data Type
- Netezza Syntax Migration
- FAQs
- Troubleshooting
- Glossary
- DataCheck
- DWS-Connector
- Server Tool
-
API Reference
- Before You Start
- API Overview
- Calling APIs
- Getting Started
-
API Description
- AZ
-
Cluster Management
- Creating a Cluster
- Creating a Cluster (V2)
- Creating a Logical Cluster
- Converting a Physical Cluster to a Logical Cluster
- Querying the Cluster List
- Querying the Logical Cluster List
- Querying Task Information About a Logical Cluster
- Querying Disk Information of a Logical Cluster
- Querying the Node List
- Querying Information About Available Ring Nodes in a Logical Cluster
- Querying Information About Ring Nodes in a Cluster Topology
- Querying Cluster Details
- Querying Node Types
- Deleting Clusters
- Deleting a Logical Cluster
- Editing a Logical Cluster
- Restarting a Logical Cluster
- Switching to a Logical Cluster
- Deleting a Node
- Scaling Out with Idle Nodes
- Resuming Redistribution
- Suspending Redistribution
- Restarting a Cluster
- Scaling Out a Cluster
- Resetting a Password
- Performing a Check Before Cluster Creation
- Scaling In a Cluster
- Delivering Redistribution
- Querying Redistribution Details
- Querying the DSS Storage Pool List
- Querying the Resource Statistics
- Performing Primary-Standby Restoration
- Removing the Read-only Status
- Adding Disk Capacity
- Modifying a Maintenance Window
- Querying Cluster CN Nodes
- Adding CN Nodes in Batches
- Deleting CN Nodes in Batches
- Querying a Cluster Parameter Group
- Querying Cluster Parameter Settings
- Modifying Parameter Settings of a Cluster
- Querying Snapshot Statistics
- Querying the Nodes to Be Removed for Scale-In
- Querying Parameter Modification Audit Records
- Saving Cluster Description
- Querying an Instance
-
Snapshot Management
- Creating a Snapshot
- Querying the Snapshot List
- Querying a Snapshot Policy
- Querying Snapshot Details
- Deleting a Manual Snapshot
- Deleting a Snapshot Policy
- Restoring a Cluster
- Checking the Name of the Table to Be Restored
- Restoring a Table
- Obtaining Available Regions of a Cross-Region Snapshot
- Configuring Cross-Region Backup
- Querying All Cross-Region Snapshot Configurations
- Deleting Cross-Region Backup Configurations
- Copying a Snapshot
- Querying the Cluster Snapshot List
- Adding a Snapshot Policy
- Event Management
- Data Source
- Audit logs
-
Resource Management
- Setting the Resource Management Switch
- Querying the Resource Management Status
- Querying Resource Statistics
- Creating a Resource Pool
- Deleting a Resource Pool
- Querying the Resource Pool List
- Obtaining Resource Pool Details
- Updating Configuration Information of a Resource Pool
- Associating a Resource Pool with a User
- Obtaining the List of Users Bound to a Resource Pool
- Unbinding a User from a Resource Pool
- Creating a Resource Management Plan
- Querying the Resource Management Plan List
- Starting a Resource Management Plan
- Viewing Plan Execution Logs
- Querying Details About a Resource Management Plan
- Stopping a Resource Management Plan
- Deleting a Resource Management Plan
- Adding a Resource Management Plan Stage
- Querying Details About a Resource Management Plan Stage
- Deleting a Resource Management Plan Stage
- Switch to Another Resource Management Plan Stage
- Querying Cluster Schema Space Information
- Updating the Space Limit of a Schema
- Alarm Management
- Connection Management
- Tag Management
- Quota Management
-
DR Management
- Creating a DR Task
- Enabling DR
- Querying the DR List
- Querying DR Details
- Querying DR Progress
- Querying the List of Available DR Clusters
- Updating DR Configurations
- Switching to the DR Cluster
- Switching to the DR Cluster Upon Production Cluster Exceptions
- Performing Cluster Restoration
- Disabling DR
- Checking the DR Name
- Deleting a DR Task
- Job Management
-
Host Monitoring
- Querying the Host Overview
- Querying Disk Information
- Obtaining the NIC Status
- Querying Performance Monitoring Metrics
- Querying Historical Monitoring Data
- Querying Table Skew or Dirty Page Rate Information
- Querying the SQL List
- Querying SQL Execution Information
- Querying the List of Metrics Used by a Cluster
- Obtains the collected data of a specified metric.
- Managing Database Permissions
- Log Management
- Upgrade Management
- Application Cases
- Introduction
- Appendix
- SDK Reference
-
FAQs
- Top FAQs
-
Product Consulting
- Why Should I Use GaussDB(DWS)?
- Should I Choose Public Cloud GaussDB(DWS) or RDS?
- What Are the Differences Between GaussDB(DWS) Users and Roles?
- How Do I Check the Creation Time of a GaussDB(DWS) Database User?
- Learn How to Select a GaussDB(DWS) Region and AZ
- Is Data Secure in GaussDB(DWS)?
- Can I Modify the Security Group of a GaussDB(DWS) Cluster?
- What Is a Database/Data Warehouse/Data Lake/Lakehouse?
- How Are Dirty Pages Generated in GaussDB(DWS)?
- How Do I Use VPC Sharing to Process GaussDB(DWS) Resources?
-
Database Connections
- How Applications Communicate with GaussDB(DWS)?
- Does GaussDB(DWS) Support Third-Party Clients and JDBC and ODBC Drivers?
- What Should I Do If I Cannot Connect to a GaussDB(DWS) Cluster?
- Why Was I Not Notified of Failure Unbinding the EIP When GaussDB(DWS) Is Connected Over the Internet?
- How Do I Configure a Whitelist to Protect GaussDB(DWS) Clusters Available Through a Public IP Address?
-
Data Migration
- What Are the Differences Between Data Formats Supported by OBS and GDS Foreign Tables in GaussDB(DWS)?
- How Does GaussDB(DWS) Store Data?
- How Much Service Data Can Be Stored in GaussDB(DWS)?
- How to Import and Export Data in GaussDB(DWS) Using \copy?
- How Do I Implement Fault Tolerance Import Between Different GaussDB(DWS) Encoding Libraries
- Which Are the Factors That Affect GaussDB(DWS) Import Performance?
-
Database Usage
- How Do I Adjust GaussDB(DWS) Distribution Columns?
- How Do I View and Set the Character Set Encoding Format of the GaussDB(DWS) Database?
- What Do I Do If Date Type Is Automatically Converted to the Timestamp Type During GaussDB(DWS) Table Creation?
- Do I Need to Run VACUUM FULL and ANALYZE on Common Tables Periodically in GaussDB(DWS)?
- How Do I Export the Structure of a GaussDB(DWS) Table?
- How Do I Delete Table Data Efficiently in GaussDB(DWS)?
- How Do I View GaussDB(DWS) Foreign Table Information?
- How Will Data Be Stored in a GaussDB(DWS) Table If No Distribution Column Is Specified During Its Creation?
- How Do I Replace the Null Results with 0 in a GaussDB(DWS) Join Query?
- How Do I Check Whether a GaussDB(DWS) Table Is Row-Stored or Column-Stored?
- How Do I Query the Information About GaussDB(DWS) Column-Store Tables?
- Why Sometimes the GaussDB(DWS) Query Indexes Become Invalid?
- How Do I Use a User-Defined GaussDB(DWS) Function to Rewrite the CRC32() Function?
- What Is a GaussDB(DWS) Schema Starting with pg_toast_temp* or pg_temp*?
- Solutions to Inconsistent GaussDB(DWS) Query Results
- Which System Catalogs in GaussDB(DWS) Cannot Be Subjected to the VACUUM FULL Operation?
- In Which Scenarios Would a GaussDB(DWS) Statement Be "idle in transaction"?
- How Does GaussDB(DWS) Implement Row-to-Column and Column-to-Row Conversion?
- What Are the Differences Between Unique Constraints and Unique Indexes in GaussDB(DWS)?
- What Are the Differences Between GaussDB(DWS) Functions and Stored Procedures?
- How Do I Delete Duplicate Table Data in GaussDB(DWS)?
-
Cluster Management
- How Can I Clear and Reclaim the Storage Space in GaussDB(DWS)?
- Why Did the Used Storage in GaussDB(DWS) Shrink After Scale-out?
- How Is the Disk Space or Capacity of GaussDB(DWS) Calculated?
- How Can I Set the Session Threshold for Cloud Eye When Adding an Alarm Rule on GaussDB(DWS)?
- How Do I Determine Whether a GaussDB(DWS) Cluster Uses the x86 or Arm Architecture?
- What Should I Do If the GaussDB(DWS) Scale-out Check Fails?
- When Should I Add CNs or Scale Out a Cluster in GaussDB(DWS)?
- When to Modify GaussDB(DWS) Classic and Elastic Specifications and When to Perform Scale-Out and Scale-In?
- How Do I Select Between Small-Scale Multi-Node and Large-Scale Three-Node Clusters with Equivalent CPU and Memory in GaussDB(DWS)?
- What Are the Differences Between Cloud SSDs and Local SSDs in GaussDB(DWS)?
- What Are the Differences Between Hot Data Storage and Cold Data Storage in GaussDB(DWS)?
- What Should I Do If the Scale-In Button of GaussDB(DWS) Is Unavailable?
-
Account Permissions
- How Does GaussDB(DWS) Implement Workload Isolation?
- How Do I Change the Password of a GaussDB(DWS) Database Account When the Password Expires?
- How Do I Grant Table Permissions to a Specified GaussDB(DWS) User?
- How Do I Grant the Permission of a Schema to a Specified GaussDB(DWS) User?
- How Do I Create a GaussDB(DWS) Database Read-Only User?
- How Do I Create Private Users and Tables in a GaussDB(DWS) Database?
- How Do I Revoke the CONNECT ON DATABASE Permission of a User on GaussDB(DWS)?
- How Do I View the Table Permissions of a GaussDB(DWS) User?
- What Is the Ruby User in the GaussDB(DWS) Database?
-
Database Performance
- Why Is SQL Execution Slow After Long GaussDB(DWS) Usage?
- Why Does GaussDB(DWS) Perform Worse Than a Single-Server Database in Extreme Scenarios?
- How Do I View SQL Execution Records of a Certain Period When GaussDB(DWS) Service Read and Write Are Blocked?
- What is Operator Spilling in GaussDB(DWS)?
- GaussDB(DWS) CPU Resource Management
- Why Is the Execution of Common GaussDB(DWS) User Slower Than That of User dbadmin?
- What Are the Factors Related to the Single-Table Query Performance in GaussDB(DWS)?
- Backup and Restoration
-
Troubleshooting
-
Database Connections
- What Do I Do If gsql: command not found Is Displayed When I Run gsql to Connect to the Database?
- Database Cannot Be Connected Using the gsql Client
- An Error Indicating Too Many Client Connections Is Reported When a User Connects to a GaussDB(DWS) Database
- Cluster IP Address Cannot Be Pinged/Accessed
- Error "An I/O error occurred while sending to the backend" Is Reported During Service Execution
- JDBC/ODBC
-
Data Import and Export
- "ERROR: invalid byte sequence for encoding 'UTF8': 0x00" Is Reported When Data Is Imported to GaussDB(DWS) Using COPY FROM
- Data Import and Export Faults with GDS
- Failed to Create a GDS Foreign Table and An Error Is Reported Indicating that ROUNDROBIN Is Not Supported
- When CDM Is Used to Import MySQL Data to GaussDB(DWS), the Column Length Exceeds the Threshold and Data Synchronization Fails
- "Access Denied" Is Displayed When the SQL Statement for Creating an OBS Foreign Table Is Executed
- Disk Usage Increases After Data Fails to Be Imported Using GDS
- Error Message "out of memory" Is Displayed When GDS Is Used to Import Data
- Error Message "connection failure error" Is Displayed During GDS Data Transmission
- Data to Be Imported Contains Chinese When the DataArts Studio Service Is Used to Create a GaussDB(DWS) Foreign Table
- Database Parameter Modification
-
Account/Permission/Password
- How Do I Unlock an Account?
- Account Still Locked After Password Resetting
- After the Permission for Querying Tables in a Schema Is Granted to a User, the User Still Cannot Query the Tables
- How Do I Revoke the Permission of a User If grant select on table t1 to public Has Been Executed on a Table
- An Error Message Is Displayed When a Common User Executes the Statement for Creating or Deleting a GDS or OBS Foreign Table, Indicating that the User Does Not Have the Permission or the Permission Is Insufficient
- After the all Permission Is Granted to the Schema of a User, the Error Message "ERROR: current user does not have privilege to role tom" Persists During Table Creation
- An Error Message Is Reported During Statement Execution, Indicating that the User Does Not Have the Required Permission
- A User Cannot Be Deleted Due to Its Dependencies
-
Cluster Performance
- Lock Wait Detection
- During SQL Execution, a Table Deadlock Occurs and An Error Stating LOCK_WAIT_TIMEOUT Is Reported
- Error "abort transaction due to concurrent update" Is Reported During SQL Execution
- Solution to High Disk Usage and Cluster Read-Only
- SQL Execution Is Slow with Low Performance and Sometimes Does Not End After a Long Period of Time
- Data Skew Causes Slow SQL Statement Execution and Operations Fail on Large Tables
- Table Size Does not Change After VACUUM FULL Is Executed on the Table
- VACUUM Is Executed After Table Data Deletion, But the Space Is Not Released
- Error "lock wait timeout" Is Reported When VACUUM FULL Is Executed
- VACUUM FULL Is Slow
- Table Bloating Causes Slow SQL Query and Failed Data Loading on the GUI
- Memory Overflow Occurs in a Cluster
- Statements with User-defined Functions Cannot Be Pushed Down
- Column-Store Tables Cannot Be Updated or Table Bloat Occurs
- Table Bloat Occurs After Data Is Inserted into a Column-Store Table for Multiple Times
- Writing Data to GaussDB(DWS) Is Slow and Client Data Is Stacked
- Low Query Efficiency
- Poor Query Performance Due to the Lack of Statistics
- Execution of SQL Statements Is Slow Due to Nested Loops in Execution Plans
- SQL Query Is Slow Because Partitions Are Not Pruned
- Optimizer Uses Nested Loop Due to the Small Estimated Number of Rows and the Performance Deteriorates
- SQL Statements Contain the in Constant and No Result Is Returned After SQL Statement Execution
- Performance of Single-Table Point Query Is Poor
- CCN Queuing Under Dynamic Load Management
- Performance Deterioration Due to Data Bloat
- Slow Performance Caused by Too Many Small CUs in Column Storage
- Reducing I/O Usage
- Tuning Systems with High CPU Usage
- Reducing Memory Usage
- Cluster Exceptions
-
Database Use
- An Error Is Reported When Data Is Inserted or Updated, Indicating that the Distribution Key Cannot Be Updated
- "Connection reset by peer" Is Displayed When a User Executes an SQL Statement
- "value too long for type character varying" Is Displayed When VARCHAR(n) Stores Chinese Characters
- Case Sensitivity in SQL Statements
- cannot drop table test because other objects depend on it Is Displayed When a Table Is Deleted
- Failed to Execute MERGE INTO UPDATE for Multiple Tables
- JDBC Error Occurs Due to session_timeout Settings
- DROP TABLE Fails to Be Executed
- Execution Results of the string_agg Function Are Inconsistent
- Error "could not open relation with OID xxxx" Is Reported During Table Size Query
- DROP TABLE IF EXISTS Syntax Misuse
- Different Data Is Displayed for the Same Table Queried By Multiple Users
- When a User Specifies Only an Index Name to Modify the Index, A Message Indicating That the Index Does Not Exist Is Displayed
- An Error Is Displayed Indicating Schema Already Exists When Executing CREATE SCHEMA Statement
- Failed to Delete a Database and an Error Is Reported Indicating that a Session Is Connected to the Database
- Byte Type Is Returned After a Table Column of the Character Type Is Read in Java
- "ERROR:start value of partition 'XX' NOT EQUAL up-boundary of last partition." Is Displayed When Operations Related to Table Partitions Are Performed
- Reindexing Fails
- A View Failed to Be Queried
- Global SQL Query
- How Do I Determine Whether UPDATE or DELETE Has Been Executed on a Table?
- "Can't fit xid into page" Is Reported
- "unable to get a stable set of rows in the source table" Is Reported
- DWS Metadata Inconsistency - Abnormal Partition Index
- An Error Is Reported When the TRUNCATE Command Is Executed on the System Table gs_wlm_session_info
- "inserted partition key does not map to any table partition" Is Reported When Data Is Inserted into a Partitioned Table
- Error upper boundary of adding partition MUST overtop last existing partition Is Reported When a New Partition Is Added to a Range Partitioned Table
- Error Reported During Table Query: "missing chunk number %d for toast value %u in pg_toast_XXXX"
- When Inserting Data Into a Table, An Error Is Reported: "duplicate key value violates unique constraint "%s""
- Error could not determine which collation to use for string hashing Reported During Service Execution
- When the ODBC Driver of GaussDB(DWS) Is Used, Content of Fields of the Character Type in the SQL Query Result Is Truncated
- Execution Plan Scan Hints Do Not Take Effect
- Error "invalid input syntax for xxx" Is Reported During Data Type Conversion
- Error UNION types %s and %s cannot be matched Is Reported
- "ERROR: Non-deterministic UPDATE" Is Reported During Update
- Error Reported During Data Insertion: null value in column ' %s' violates not-null constraint
- Error "unable to get a stable set of rows in the source table"
- Query Results Are Inconsistent in Oracle, Teradata, and MySQL Compatibility Modes
-
Database Connections
- Videos
- Performance White Paper
-
Technical White Paper
- GaussDB(DWS)
- Platforms and Technical Specifications Supported by GaussDB(DWS)
-
GaussDB(DWS) Core Technologies
- Shared-Nothing Architecture
- Data Distribution in a Distributed System
- Fully Parallel Query
- Vectorized Executor and Hybrid Row-Column Storage Engine
- Resource Monitoring and Management
- Distributed Transactions
- Online Scale-Out
- SQL on Anywhere
- Cluster Management and HA
- SQL Self-Diagnosis
- Transparent Data Encryption
- Data Masking
- Data Backup and Disaster Recovery
- GaussDB(DWS) Tools
- External APIs
-
Error Code Reference
-
8.2.0 and earlier versions
- Management Console Error Code
-
Data Warehouse Service Error Codes
- Description of SQL Error Codes
- Third-Party Library Error Codes
- GAUSS-00001 -- GAUSS-00100
- GAUSS-00101 -- GAUSS-00200
- GAUSS-00201 -- GAUSS-00300
- GAUSS-00301 -- GAUSS-00400
- GAUSS-00401 -- GAUSS-00500
- GAUSS-00501 -- GAUSS-00600
- GAUSS-00601 -- GAUSS-00700
- GAUSS-00701 -- GAUSS-00800
- GAUSS-00801 -- GAUSS-00900
- GAUSS-00901 -- GAUSS-01000
- GAUSS-01001 -- GAUSS-01100
- GAUSS-01101 -- GAUSS-01200
- GAUSS-01201 -- GAUSS-01300
- GAUSS-01301 -- GAUSS-01400
- GAUSS-01401 -- GAUSS-01500
- GAUSS-01501 -- GAUSS-01600
- GAUSS-01601 -- GAUSS-01700
- GAUSS-01701 -- GAUSS-01800
- GAUSS-01801 -- GAUSS-01900
- GAUSS-01901 -- GAUSS-02000
- GAUSS-02001 -- GAUSS-02100
- GAUSS-02101 -- GAUSS-02200
- GAUSS-02201 -- GAUSS-02300
- GAUSS-02301 -- GAUSS-02400
- GAUSS-02401 -- GAUSS-02500
- GAUSS-02501 -- GAUSS-02600
- GAUSS-02601 -- GAUSS-02700
- GAUSS-02701 -- GAUSS-02800
- GAUSS-02801 -- GAUSS-02900
- GAUSS-02901 -- GAUSS-03000
- GAUSS-03001 -- GAUSS-03100
- GAUSS-03101 -- GAUSS-03200
- GAUSS-03201 -- GAUSS-03300
- GAUSS-03301 -- GAUSS-03400
- GAUSS-03401 -- GAUSS-03500
- GAUSS-03501 -- GAUSS-03600
- GAUSS-03601 -- GAUSS-03700
- GAUSS-03701 -- GAUSS-03800
- GAUSS-03801 -- GAUSS-03900
- GAUSS-03901 -- GAUSS-04000
- GAUSS-04001 -- GAUSS-04100
- GAUSS-04101 -- GAUSS-04200
- GAUSS-04201 -- GAUSS-04300
- GAUSS-04301 -- GAUSS-04400
- GAUSS-04401 -- GAUSS-04500
- GAUSS-04501 -- GAUSS-04600
- GAUSS-04601 -- GAUSS-04700
- GAUSS-04701 -- GAUSS-04800
- GAUSS-04901 -- GAUSS-04999
- GAUSS-05101 -- GAUSS-05200
- GAUSS-05201 -- GAUSS-05800
- GAUSS-05801 -- GAUSS-05900
- GAUSS-05901 -- GAUSS-05999
- GAUSS-06101 -- GAUSS-06200
- GAUSS-50000 -- GAUSS-50999
- GAUSS-51000 -- GAUSS-51999
- GAUSS-52000 -- GAUSS-52999
- GAUSS-53000 -- GAUSS-53999
- OE000
- 8.2.1 or later versions
-
8.2.0 and earlier versions
- Glossary
-
More Documents
-
User Guide
- Service Overview
- Getting Started
- Process for Using GaussDB(DWS)
- Preparations
- Cluster Configuration
-
Cluster Connection
- Methods of Connecting to a Cluster
- Obtaining the Cluster Connection Address
- Using the gsql CLI Client to Connect to a Cluster
- Using the Data Studio GUI Client to Connect to a Cluster
- Using the JDBC and ODBC Drivers to Connect to a Cluster
- Using the Python Library psycopg2 to Connect to a Cluster
- Using the Python Library PyGreSQL to Connect to a Cluster
- Managing Database Connections
-
Clusters
- Checking the Cluster Status
- Viewing Basic Cluster Information
- Managing Access Domain Names
- Cluster Scale-out
- Performing a Primary/Standby Switchback
- Cluster Upgrade
- Password Reset
- Cluster Restart
- Modifying Database Parameters
- MRS Data Sources
- Managing Logical Clusters
- Managing Tags
- Deleting Clusters
- Managing Parameter Templates
- Managing Clusters That Fail to Be Created
- Cluster HA
- Monitoring and Alarms
- Cluster Security Management
- Audit Logs
-
FAQs
-
General Problems
- Why Are Data Warehouses Necessary?
- What Are the Differences Between a Data Warehouse and the Hadoop Big Data Platform?
- Why Should I Use GaussDB(DWS)?
- When Should I Use GaussDB(DWS) and MRS?
- What Are the Differences Between GaussDB(DWS) and Hive in Functions?
- What Is the User Quota?
- What Are the Differences Between Users and Roles?
- How Do I Check the Creation Time of a Database User?
- Regions and AZs
- Is My Data Secure in GaussDB(DWS)?
- How Is GaussDB(DWS) Secured?
- Can I Modify the Security Group of a GaussDB(DWS) Cluster?
- What Is a Database/Data Warehouse/Data Lake/Lakehouse?
-
Cluster Management
- What Do I Do If Creating a GaussDB(DWS) Cluster Failed?
- How Can I Clear and Reclaim the Storage Space?
- Why Did the Used Storage Shrink After Scale-out?
- How Do I View Node Metrics (CPU, Memory, and Disk Usage)?
- Does GaussDB(DWS) Support a Single Node for a Learning Environment?
- How Is the Disk Space or Capacity of GaussDB(DWS) Calculated?
- What Are the gaussdb and postgres Databases of GaussDB(DWS)?
- How Do I Set the Maximum Number of Sessions When Adding an Alarm Rule on Cloud Eye?
- When Should I Add CNs or Scale out a cluster?
- What Are the Differences Between Hot Data Storage and Cold Data Storage?
-
Database Connections
- How Applications Communicate with GaussDB(DWS)?
- Does GaussDB(DWS) Support Third-Party Clients and JDBC and ODBC Drivers?
- Can I Connect to GaussDB(DWS) Cluster Nodes Using SSH?
- What Should I Do If I Cannot Connect to a Data Warehouse Cluster?
- Why Was I Not Notified of Failure Unbinding the EIP When GaussDB(DWS) Is Connected Over the Internet?
- How Do I Configure a Whitelist to Protect Clusters Available Through a Public IP Address?
-
Data Import and Export
- What Are the Differences Between Data Formats Supported by OBS and GDS Foreign Tables?
- How Do I Import Incremental Data Using an OBS Foreign Table?
- How Can I Import Data to GaussDB(DWS)?
- How Much Service Data Can a Data Warehouse Store?
- How Do I Use \Copy to Import and Export Data?
- Can I Export GaussDB(DWS) Data from/to OBS Across Regions?
- How Do I Import GaussDB(DWS)/Oracle/MySQL/SQL Server Data to GaussDB(DWS) (Whole Database Migration)?
- Can I Import Data over the Public/External Network Using GDS?
- Which Are the Factors That Affect GaussDB(DWS) Import Performance?
-
Account, Password, and Permissions
- How Does GaussDB(DWS) Implement Workload Isolation?
- How Do I Change the Password of a Database Account When the Password Expires?
- How Do I Grant Table Permissions to a User?
- How Do I Grant Schema Permissions to a User?
- How Do I Create a Database Read-only User?
- How Do I Create Private Database Users and Tables?
- How Do I Revoke the CONNECT ON DATABASE Permission from a User?
- How Do I View the Table Permissions of a User?
- Who Is User Ruby?
-
Database Usage
- How Do I Change Distribution Columns?
- How Do I View and Set the Database Character Encoding?
- What Do I Do If Date Type Is Automatically Converted to the Timestamp Type During Table Creation?
- Do I Need to Run VACUUM FULL and ANALYZE on Common Tables Periodically?
- Do I Need to Set a Distribution Key After Setting a Primary Key?
- Is GaussDB(DWS) Compatible with PostgreSQL Stored Procedures?
- What Are Partitioned Tables, Partitions, and Partition Keys?
- How Can I Export the Table Structure?
- How Can I Export All Tables and Views from a Database?
- How Can I Delete Table Data Efficiently?
- How Do I View Foreign Table Information?
- If No Distribution Column Is Specified, How Will Data Be Stored?
- How Do I Replace the Null Result with 0?
- How Do I Check Whether a Table Is Row-Stored or Column-Stored?
- How Do I Query the Information About GaussDB(DWS) Column-Store Tables?
- Why Sometimes the GaussDB(DWS) Query Indexes Become Invalid?
- How Do I Use a User-Defined Function to Rewrite the CRC32() Function?
- What Are the Schemas Starting with pg_toast_temp* or pg_temp*?
- Solutions to Inconsistent GaussDB(DWS) Query Results
- Which System Catalogs That the VACUUM FULL Operation Cannot Be Performed on?
- In Which Scenarios Would a Statement Be "idle in transaction"?
- Database Performance
- Snapshot Backup and Restoration
-
General Problems
- Change History
- API Reference (ME-Abu Dhabi Region)
-
Developer Guide (ME-Abu Dhabi Region)
- Welcome
- System Overview
-
Data Migration
- Data Migration to GaussDB(DWS)
- Data Import
- Full Database Migration
- Meta-command Migration
- Data Export
- Appendices
- Syntax Compatibility Differences Among Oracle, Teradata, and MySQL
- Database Security Management
- Development and Design Proposal
-
Guide: JDBC- or ODBC-Based Development
- Development Specifications
- Downloading Drivers
-
JDBC-Based Development
- JDBC Package and Driver Class
- Development Process
- Loading a Driver
- Connecting to a Database
- Executing SQL Statements
- Processing Data in a Result Set
- Closing the Connection
- Example: Common Operations
- Example: Retrying SQL Queries for Applications
- Example: Importing and Exporting Data Through Local Files
- Example: Migrating Data from MySQL to GaussDB(DWS)
-
JDBC Interface Reference
- java.sql.Connection
- java.sql.CallableStatement
- java.sql.DatabaseMetaData
- java.sql.Driver
- java.sql.PreparedStatement
- java.sql.ResultSet
- java.sql.ResultSetMetaData
- java.sql.Statement
- javax.sql.ConnectionPoolDataSource
- javax.sql.DataSource
- javax.sql.PooledConnection
- javax.naming.Context
- javax.naming.spi.InitialContextFactory
- CopyManager
- ODBC-Based Development
- PostGIS Extension
- Resource Load Management
-
Query Performance Optimization
- Optimization Overview
- Overview of Query Performance Optimization
- Query Analysis
- System Optimization
-
Query Improvement
- Query Execution Process
- Introduction to the SQL Execution Plan
- Optimization Process
- Updating Statistics
- Reviewing and Modifying a Table Definition
- Typical SQL Optimization Methods
- Experience in Rewriting SQL Statements
- Adjusting Key Parameters During SQL Tuning
- Hint-based Tuning
- Routinely Maintaining Tables
- Routinely Recreating an Index
- Configuring the SMP
-
Optimization Cases
- Case: Selecting an Appropriate Distribution Column
- Case: Creating an Appropriate Index
- Case: Adding NOT NULL for JOIN Columns
- Case: Pushing Down Sort Operations to DNs
- Case: Configuring cost_param for Better Query Performance
- Case: Adjusting the Distribution Key
- Case: Adjusting the Partial Clustering Key
- Case: Adjusting the Table Storage Mode in a Medium Table
- Case: Adjusting the Local Clustering Column
- Case: Reconstructing Partition Tables
- Case: Adjusting the GUC Parameter best_agg_plan
- Case: Rewriting SQL and Deleting Subqueries (Case 1)
- Case: Rewriting SQL and Deleting Subqueries (Case 2)
- Case: Rewriting SQL Statements and Eliminating Prune Interference
- Case: Rewriting SQL Statements and Deleting in-clause
- Case: Setting Partial Cluster Keys
- SQL Execution Troubleshooting
- Common Performance Parameter Optimization Design
- User-Defined Functions
- Stored Procedures
-
System Catalogs and System Views
- Overview of System Catalogs and System Views
-
System Catalogs
- GS_OBSSCANINFO
- GS_WLM_INSTANCE_HISTORY
- GS_WLM_OPERATOR_INFO
- GS_WLM_SESSION_INFO
- GS_WLM_USER_RESOURCE_HISTORY
- PG_AGGREGATE
- PG_AM
- PG_AMOP
- PG_AMPROC
- PG_ATTRDEF
- PG_ATTRIBUTE
- PG_AUTHID
- PG_AUTH_HISTORY
- PG_AUTH_MEMBERS
- PG_CAST
- PG_CLASS
- PG_COLLATION
- PG_CONSTRAINT
- PG_CONVERSION
- PG_DATABASE
- PG_DB_ROLE_SETTING
- PG_DEFAULT_ACL
- PG_DEPEND
- PG_DESCRIPTION
- PG_ENUM
- PG_EXTENSION
- PG_EXTENSION_DATA_SOURCE
- PG_FOREIGN_DATA_WRAPPER
- PG_FOREIGN_SERVER
- PG_FOREIGN_TABLE
- PG_INDEX
- PG_INHERITS
- PG_JOBS
- PG_LANGUAGE
- PG_LARGEOBJECT
- PG_LARGEOBJECT_METADATA
- PG_NAMESPACE
- PG_OBJECT
- PG_OBSSCANINFO
- PG_OPCLASS
- PG_OPERATOR
- PG_OPFAMILY
- PG_PARTITION
- PG_PLTEMPLATE
- PG_PROC
- PG_RANGE
- PG_REDACTION_COLUMN
- PG_REDACTION_POLICY
- PG_RLSPOLICY
- PG_RESOURCE_POOL
- PG_REWRITE
- PG_SECLABEL
- PG_SHDEPEND
- PG_SHDESCRIPTION
- PG_SHSECLABEL
- PG_STATISTIC
- PG_STATISTIC_EXT
- PG_SYNONYM
- PG_TABLESPACE
- PG_TRIGGER
- PG_TS_CONFIG
- PG_TS_CONFIG_MAP
- PG_TS_DICT
- PG_TS_PARSER
- PG_TS_TEMPLATE
- PG_TYPE
- PG_USER_MAPPING
- PG_USER_STATUS
- PG_WORKLOAD_ACTION
- PGXC_CLASS
- PGXC_GROUP
- PGXC_NODE
-
System Views
- ALL_ALL_TABLES
- ALL_CONSTRAINTS
- ALL_CONS_COLUMNS
- ALL_COL_COMMENTS
- ALL_DEPENDENCIES
- ALL_IND_COLUMNS
- ALL_IND_EXPRESSIONS
- ALL_INDEXES
- ALL_OBJECTS
- ALL_PROCEDURES
- ALL_SEQUENCES
- ALL_SOURCE
- ALL_SYNONYMS
- ALL_TAB_COLUMNS
- ALL_TAB_COMMENTS
- ALL_TABLES
- ALL_USERS
- ALL_VIEWS
- DBA_DATA_FILES
- DBA_USERS
- DBA_COL_COMMENTS
- DBA_CONSTRAINTS
- DBA_CONS_COLUMNS
- DBA_IND_COLUMNS
- DBA_IND_EXPRESSIONS
- DBA_IND_PARTITIONS
- DBA_INDEXES
- DBA_OBJECTS
- DBA_PART_INDEXES
- DBA_PART_TABLES
- DBA_PROCEDURES
- DBA_SEQUENCES
- DBA_SOURCE
- DBA_SYNONYMS
- DBA_TAB_COLUMNS
- DBA_TAB_COMMENTS
- DBA_TAB_PARTITIONS
- DBA_TABLES
- DBA_TABLESPACES
- DBA_TRIGGERS
- DBA_VIEWS
- DUAL
- GLOBAL_REDO_STAT
- GLOBAL_REL_IOSTAT
- GLOBAL_STAT_DATABASE
- GLOBAL_WORKLOAD_SQL_COUNT
- GLOBAL_WORKLOAD_SQL_ELAPSE_TIME
- GLOBAL_WORKLOAD_TRANSACTION
- GS_ALL_CONTROL_GROUP_INFO
- GS_CLUSTER_RESOURCE_INFO
- GS_INSTR_UNIQUE_SQL
- GS_REL_IOSTAT
- GS_NODE_STAT_RESET_TIME
- GS_SESSION_CPU_STATISTICS
- GS_SESSION_MEMORY_STATISTICS
- GS_SQL_COUNT
- GS_WAIT_EVENTS
- GS_WLM_OPERAROR_INFO
- GS_WLM_OPERATOR_HISTORY
- GS_WLM_OPERATOR_STATISTICS
- GS_WLM_SESSION_INFO
- GS_WLM_SESSION_HISTORY
- GS_WLM_SESSION_STATISTICS
- GS_WLM_SQL_ALLOW
- GS_WORKLOAD_SQL_COUNT
- GS_WORKLOAD_SQL_ELAPSE_TIME
- GS_WORKLOAD_TRANSACTION
- GS_STAT_DB_CU
- GS_STAT_SESSION_CU
- GS_TOTAL_NODEGROUP_MEMORY_DETAIL
- GS_USER_TRANSACTION
- GS_VIEW_DEPENDENCY
- GS_VIEW_DEPENDENCY_PATH
- GS_VIEW_INVALID
- PG_AVAILABLE_EXTENSION_VERSIONS
- PG_AVAILABLE_EXTENSIONS
- PG_BULKLOAD_STATISTICS
- PG_COMM_CLIENT_INFO
- PG_COMM_DELAY
- PG_COMM_STATUS
- PG_COMM_RECV_STREAM
- PG_COMM_SEND_STREAM
- PG_CONTROL_GROUP_CONFIG
- PG_CURSORS
- PG_EXT_STATS
- PG_GET_INVALID_BACKENDS
- PG_GET_SENDERS_CATCHUP_TIME
- PG_GROUP
- PG_INDEXES
- PG_JOB
- PG_JOB_PROC
- PG_JOB_SINGLE
- PG_LIFECYCLE_DATA_DISTRIBUTE
- PG_LOCKS
- PG_NODE_ENV
- PG_OS_THREADS
- PG_POOLER_STATUS
- PG_PREPARED_STATEMENTS
- PG_PREPARED_XACTS
- PG_QUERYBAND_ACTION
- PG_REPLICATION_SLOTS
- PG_ROLES
- PG_RULES
- PG_RUNNING_XACTS
- PG_SECLABELS
- PG_SESSION_WLMSTAT
- PG_SESSION_IOSTAT
- PG_SETTINGS
- PG_SHADOW
- PG_SHARED_MEMORY_DETAIL
- PG_STATS
- PG_STAT_ACTIVITY
- PG_STAT_ALL_INDEXES
- PG_STAT_ALL_TABLES
- PG_STAT_BAD_BLOCK
- PG_STAT_BGWRITER
- PG_STAT_DATABASE
- PG_STAT_DATABASE_CONFLICTS
- PG_STAT_GET_MEM_MBYTES_RESERVED
- PG_STAT_USER_FUNCTIONS
- PG_STAT_USER_INDEXES
- PG_STAT_USER_TABLES
- PG_STAT_REPLICATION
- PG_STAT_SYS_INDEXES
- PG_STAT_SYS_TABLES
- PG_STAT_XACT_ALL_TABLES
- PG_STAT_XACT_SYS_TABLES
- PG_STAT_XACT_USER_FUNCTIONS
- PG_STAT_XACT_USER_TABLES
- PG_STATIO_ALL_INDEXES
- PG_STATIO_ALL_SEQUENCES
- PG_STATIO_ALL_TABLES
- PG_STATIO_SYS_INDEXES
- PG_STATIO_SYS_SEQUENCES
- PG_STATIO_SYS_TABLES
- PG_STATIO_USER_INDEXES
- PG_STATIO_USER_SEQUENCES
- PG_STATIO_USER_TABLES
- PG_THREAD_WAIT_STATUS
- PG_TABLES
- PG_TIMEZONE_ABBREVS
- PG_TIMEZONE_NAMES
- PG_TOTAL_MEMORY_DETAIL
- PG_TOTAL_SCHEMA_INFO
- PG_TOTAL_USER_RESOURCE_INFO
- PG_USER
- PG_USER_MAPPINGS
- PG_VIEWS
- PG_WLM_STATISTICS
- PGXC_BULKLOAD_PROGRESS
- PGXC_BULKLOAD_STATISTICS
- PGXC_COMM_CLIENT_INFO
- PGXC_COMM_DELAY
- PGXC_COMM_RECV_STREAM
- PGXC_COMM_SEND_STREAM
- PGXC_COMM_STATUS
- PGXC_DEADLOCK
- PGXC_GET_STAT_ALL_TABLES
- PGXC_GET_STAT_ALL_PARTITIONS
- PGXC_GET_TABLE_SKEWNESS
- PGXC_GTM_SNAPSHOT_STATUS
- PGXC_INSTANCE_TIME
- PGXC_INSTR_UNIQUE_SQL
- PGXC_LOCK_CONFLICTS
- PGXC_NODE_ENV
- PGXC_NODE_STAT_RESET_TIME
- PGXC_OS_RUN_INFO
- PGXC_OS_THREADS
- PGXC_PREPARED_XACTS
- PGXC_REDO_STAT
- PGXC_REL_IOSTAT
- PGXC_REPLICATION_SLOTS
- PGXC_RUNNING_XACTS
- PGXC_SETTINGS
- PGXC_STAT_ACTIVITY
- PGXC_STAT_BAD_BLOCK
- PGXC_STAT_BGWRITER
- PGXC_STAT_DATABASE
- PGXC_STAT_REPLICATION
- PGXC_SQL_COUNT
- PGXC_THREAD_WAIT_STATUS
- PGXC_TOTAL_MEMORY_DETAIL
- PGXC_TOTAL_SCHEMA_INFO
- PGXC_TOTAL_SCHEMA_INFO_ANALYZE
- PGXC_USER_TRANSACTION
- PGXC_VARIABLE_INFO
- PGXC_WAIT_EVENTS
- PGXC_WLM_OPERATOR_HISTORY
- PGXC_WLM_OPERATOR_INFO
- PGXC_WLM_OPERATOR_STATISTICS
- PGXC_WLM_SESSION_INFO
- PGXC_WLM_SESSION_HISTORY
- PGXC_WLM_SESSION_STATISTICS
- PGXC_WLM_WORKLOAD_RECORDS
- PGXC_WORKLOAD_SQL_COUNT
- PGXC_WORKLOAD_SQL_ELAPSE_TIME
- PGXC_WORKLOAD_TRANSACTION
- PLAN_TABLE
- PLAN_TABLE_DATA
- PV_FILE_STAT
- PV_INSTANCE_TIME
- PV_OS_RUN_INFO
- PV_SESSION_MEMORY
- PV_SESSION_MEMORY_DETAIL
- PV_SESSION_STAT
- PV_SESSION_TIME
- PV_TOTAL_MEMORY_DETAIL
- PV_REDO_STAT
- REDACTION_COLUMNS
- REDACTION_POLICIES
- USER_COL_COMMENTS
- USER_CONSTRAINTS
- USER_CONS_COLUMNS
- USER_INDEXES
- USER_IND_COLUMNS
- USER_IND_EXPRESSIONS
- USER_IND_PARTITIONS
- USER_JOBS
- USER_OBJECTS
- USER_PART_INDEXES
- USER_PART_TABLES
- USER_PROCEDURES
- USER_SEQUENCES
- USER_SOURCE
- USER_SYNONYMS
- USER_TAB_COLUMNS
- USER_TAB_COMMENTS
- USER_TAB_PARTITIONS
- USER_TABLES
- USER_TRIGGERS
- USER_VIEWS
- V$SESSION
- V$SESSION_LONGOPS
-
GUC Parameters
- Viewing GUC Parameters
- Configuring GUC Parameters
- GUC Parameter Usage
- Connection and Authentication
- Resource Consumption
- Parallel Data Import
- Write Ahead Logs
- HA Replication
- Query Planning
- Error Reporting and Logging
- Alarm Detection
- Statistics During the Database Running
- Workload Management
- Automatic Cleanup
- Default Settings of Client Connection
- Lock Management
- Version and Platform Compatibility
- Fault Tolerance
- Connection Pool Parameters
- Cluster Transaction Parameters
- Developer Operations
- Auditing
- Transaction Monitoring
- Miscellaneous Parameters
- Glossary
-
SQL Syntax Reference (ME-Abu Dhabi Region)
- GaussDB(DWS) SQL
- Differences Between GaussDB(DWS) and PostgreSQL
- Keyword
- Data Types
- Constant and Macro
-
Functions and Operators
- Logical Operators
- Comparison Operators
- Character Processing Functions and Operators
- Binary String Functions and Operators
- Bit String Functions and Operators
- Pattern Matching Operators
- Mathematical Functions and Operators
- Date and Time Processing Functions and Operators
- Type Conversion Functions
- Geometric Functions and Operators
- Network Address Functions and Operators
- Text Search Functions and Operators
- UUID Functions
- JSON Functions
- HLL Functions and Operators
- SEQUENCE Functions
- Array Functions and Operators
- Range Functions and Operators
- Aggregate Functions
- Window Functions
- Security Functions
- Set Returning Functions
- Conditional Expression Functions
- System Information Functions
-
System Administration Functions
- Configuration Settings Functions
- Universal File Access Functions
- Server Signaling Functions
- Backup and Restoration Control Functions
- Snapshot Synchronization Functions
- Database Object Functions
- Advisory Lock Functions
- Residual File Management Functions
- Replication Functions
- Other Functions
- Resource Management Functions
- Data Redaction Functions
- Statistics Information Functions
- Trigger Functions
- XML Functions
- Call Stack Recording Functions
- Expressions
- Type Conversion
- Full Text Search
- System Operation
- Controlling Transactions
-
DDL Syntax
- DDL Syntax Overview
- ALTER DATABASE
- ALTER FOREIGN TABLE (for GDS)
- ALTER FOREIGN TABLE (for HDFS or OBS)
- ALTER FUNCTION
- ALTER GROUP
- ALTER INDEX
- ALTER LARGE OBJECT
- ALTER REDACTION POLICY
- ALTER RESOURCE POOL
- ALTER ROLE
- ALTER ROW LEVEL SECURITY POLICY
- ALTER SCHEMA
- ALTER SEQUENCE
- ALTER SERVER
- ALTER SESSION
- ALTER SYNONYM
- ALTER SYSTEM KILL SESSION
- ALTER TABLE
- ALTER TABLE PARTITION
- ALTER TEXT SEARCH CONFIGURATION
- ALTER TEXT SEARCH DICTIONARY
- ALTER TRIGGER
- ALTER TYPE
- ALTER USER
- ALTER VIEW
- CLEAN CONNECTION
- CLOSE
- CLUSTER
- COMMENT
- CREATE BARRIER
- CREATE DATABASE
- CREATE FOREIGN TABLE (for GDS Import and Export)
- CREATE FOREIGN TABLE (for OBS Import and Export)
- CREATE FOREIGN TABLE (SQL on Hadoop or OBS)
- CREATE FUNCTION
- CREATE GROUP
- CREATE INDEX
- CREATE REDACTION POLICY
- CREATE ROW LEVEL SECURITY POLICY
- CREATE PROCEDURE
- CREATE RESOURCE POOL
- CREATE ROLE
- CREATE SCHEMA
- CREATE SEQUENCE
- CREATE SERVER
- CREATE SYNONYM
- CREATE TABLE
- CREATE TABLE AS
- CREATE TABLE PARTITION
- CREATE TABLESPACE
- CREATE TEXT SEARCH CONFIGURATION
- CREATE TEXT SEARCH DICTIONARY
- CREATE TRIGGER
- CREATE TYPE
- CREATE USER
- CREATE VIEW
- CURSOR
- DROP DATABASE
- DROP FOREIGN TABLE
- DROP FUNCTION
- DROP GROUP
- DROP INDEX
- DROP OWNED
- DROP REDACTION POLICY
- DROP ROW LEVEL SECURITY POLICY
- DROP PROCEDURE
- DROP RESOURCE POOL
- DROP ROLE
- DROP SCHEMA
- DROP SEQUENCE
- DROP SERVER
- DROP SYNONYM
- DROP TABLE
- DROP TABLESPACE
- DROP TEXT SEARCH CONFIGURATION
- DROP TEXT SEARCH DICTIONARY
- DROP TRIGGER
- DROP TYPE
- DROP USER
- DROP VIEW
- FETCH
- MOVE
- REINDEX
- RESET
- SET
- SET CONSTRAINTS
- SET ROLE
- SET SESSION AUTHORIZATION
- SHOW
- TRUNCATE
- VACUUM
- DML Syntax
- DCL Syntax
- DQL Syntax
- TCL Syntax
- GIN Indexes
-
Tool Guide (ME-Abu Dhabi Region)
- Overview
- Downloading Client Tools
- gsql - CLI Client
-
Data Studio - Integrated Database Development Tool
- About Data Studio
- Installing and Configuring Data Studio
- Quick Start
- Data Studio GUI
- Data Studio Menus
- Data Studio Toolbar
- Data Studio Right-Click Menus
- Connection Profiles
- Databases
- Schemas
- Creating a Function/Procedure
- Editing a Function/Procedure
- Granting/Revoking a Permission (Function/Procedure)
- Debugging a PL/SQL Function
- Working with Functions/Procedures
- GaussDB(DWS) Tables
- Sequences
- Views
-
SQL Terminal
- Opening Multiple SQL Terminal Tabs
- Managing the History of Executed SQL Queries
- Opening and Saving SQL Scripts
- Viewing Object Properties in the SQL Terminal
- Canceling the Execution of SQL Queries
- Formatting of SQL Queries
- Selecting a DB Object in the SQL Terminal
- Viewing the Execution Plan and Costs
- Viewing the Query Execution Plan and Cost Graphically
- Using SQL Terminals
- Exporting Query Results
- Managing SQL Terminal Connections
- Batch Operation
- Personalizing Data Studio
- Performance Specifications
- Security Management
- Troubleshooting
- FAQs
- GDS: Parallel Data Loader
-
DSC: SQL Syntax Migration Tool
- Overview
- Supported Keywords and Features
- Constraints and Limitations
- System Requirements
- Installing DSC
- Configuring DSC
- Using DSC
- Teradata Syntax Migration
-
Oracle Syntax Migration
- Overview
- Schema Objects
- COMPRESS Phrase
- Bitmap Index
- Custom Tablespace
- Supplemental Log Data
- LONG RAW
- DML
- Pseudo Columns
- OUTER JOIN
- OUTER QUERY (+)
- CONNECT BY
- System Functions
- PL/SQL
- PL/SQL Collections (Using User-Defined Types)
- PL/SQL Packages
- VARRAY
- Granting Execution Permissions
- Package Name List
- Data Type
- Chinese Character Support
- Netezza Syntax Migration
- MySQL Syntax Migration
- DB2 Syntax Migration
- Command Reference
- Log Reference
- Troubleshooting
- FAQs
- Security Management
- Server Tool
- Error Code Reference (ME-Abu Dhabi Region)
-
User Guide (Paris Region)
- Service Overview
- Getting Started
- Process for Using GaussDB(DWS)
- Preparations
- Creating or Deleting a Cluster
-
Cluster Connection
- Methods of Connecting to a Cluster
- Obtaining the Cluster Connection Address
- Using the Data Studio GUI Client to Connect to a Cluster
- Using the gsql CLI Client to Connect to a Cluster
- Using the JDBC and ODBC Drivers to Connect to a Cluster
- Using the Third-Party Function Library psycopg2 of Python to Connect to a Cluster
- Using the Python Library PyGreSQL to Connect to a Cluster
- Managing Database Connections
- Monitoring and Alarms
- Specifications Change and Scaling
- Backup and Disaster Recovery
- Intelligent O&M
-
Cluster Management
- Modifying Database Parameters
- Checking the Cluster Status
- Viewing Cluster Details
- Managing Access Domain Names
- Cluster Topology
- Managing Tags
- Managing Enterprise Projects
- Managing Clusters That Fail to Be Created
- Removing the Read-only Status
- Performing a Primary/Standby Switchback
- Cluster Restart
- Resetting a Password
- Cluster Upgrade
- Associating and Disassociating ELB
- Managing CNs
- Cluster Log Management
- Database User Management
- Audit Logs
- Cluster Security Management
- Resource Management
- Data Source Management
-
Managing Logical Clusters
- Logical Cluster Overview
- Adding Logical Clusters
- Editing Logical Clusters
- Managing Resources (in a Logical Cluster)
- Restarting Logical Clusters
- Scaling Out Logical Clusters
- Deleting Logical Clusters
- Tutorial: Converting a Physical Cluster That Contains Data into a Logical Cluster
- Tutorial: Dividing a New Physical Cluster into Logical Clusters
-
FAQs
-
General Problems
- Why Do I Need to Use a Data Warehouse?
- What Are the Differences Between Users and Roles?
- When Should I Use GaussDB(DWS) and MRS?
- How Do I Check the Creation Time of a Database User?
- Regions and AZs
- Is My Data Secure in GaussDB(DWS)?
- How Is GaussDB(DWS) Secured?
- Can I Modify the Security Group of a GaussDB(DWS) Cluster?
- How Are Dirty Pages Generated in GaussDB(DWS)?
-
Database Usage
- How Do I Change Distribution Columns?
- How Do I View and Set the Database Character Encoding?
- What Do I Do If Date Type Is Automatically Converted to the Timestamp Type During Table Creation?
- Do I Need to Run VACUUM FULL and ANALYZE on Common Tables Periodically?
- Do I Need to Set a Distribution Key After Setting a Primary Key?
- Is GaussDB(DWS) Compatible with PostgreSQL Stored Procedures?
- What Are Partitioned Tables, Partitions, and Partition Keys?
- How Can I Export the Table Structure?
- How Do I Delete Table Data Efficiently?
- How Do I View Foreign Table Information?
- If No Distribution Column Is Specified, How Will Data Be Stored?
- How Do I Replace the Null Result with 0?
- How Do I Check Whether a Table Is Row-Stored or Column-Stored?
- How Do I Query the Information About GaussDB(DWS) Column-Store Tables?
- Why Sometimes the GaussDB(DWS) Query Indexes Become Invalid?
- How Do I Use a User-Defined Function to Rewrite the CRC32() Function?
- What Are the Schemas Starting with pg_toast_temp* or pg_temp*?
- Solutions to Inconsistent GaussDB(DWS) Query Results
- Which System Catalogs That the VACUUM FULL Operation Cannot Be Performed on?
- In Which Scenarios Would a Statement Be "idle in transaction"?
- How Does GaussDB(DWS) Implement Row-to-Column and Column-to-Row Conversion?
- What Are the Differences Between Unique Constraints and Unique Indexes?
- What Are the Differences Between Functions and Stored Procedures?
- How Do I Delete Duplicate Table Data?
-
Cluster Management
- What Do I Do If Creating a GaussDB(DWS) Cluster Failed?
- How Can I Clear and Reclaim the Storage Space?
- Why Did the Used Storage Shrink After Scale-out?
- How Do I View Node Metrics (CPU, Memory, and Disk Usage)?
- How Is the Disk Space or Capacity of GaussDB(DWS) Calculated?
- What Are the gaussdb and postgres Databases of GaussDB(DWS)?
- How Do I Set the Maximum Number of Sessions When Adding an Alarm Rule on Cloud Eye?
- When Should I Add CNs or Scale out a cluster?
- How Should I Select from a Small-Flavor Many-Node Cluster and a Large-Flavor Three-Node Cluster with Same CPU Cores and Memory?
- What Are the Differences Between Hot Data Storage and Cold Data Storage?
- What Do I do if the Scale-in Button Is Dimmed?
-
Database Connections
- How Applications Communicate with GaussDB(DWS)?
- Does GaussDB(DWS) Support Third-Party Clients and JDBC and ODBC Drivers?
- Can I Connect to GaussDB(DWS) Cluster Nodes Using SSH?
- What Should I Do If I Cannot Connect to a GaussDB(DWS) Cluster?
- Why Was I Not Notified of Failure Unbinding the EIP When GaussDB(DWS) Is Connected Over the Internet?
- How Do I Configure a Whitelist to Protect Clusters Available Through a Public IP Address?
-
Data Import and Export
- What Are the Differences Between Data Formats Supported by OBS and GDS Foreign Tables?
- How Do I Import Incremental Data Using an OBS Foreign Table?
- How Can I Import Data to GaussDB(DWS)?
- How Much Service Data Can a Data Warehouse Store?
- How Do I Use \Copy to Import and Export Data?
- How Do I Implement Fault Tolerance Import Between Different Encoding Libraries
- Can I Import and Export Data to and from OBS Across Regions?
- Can I Import Data over the Public/External Network Using GDS?
- Which Are the Factors That Affect GaussDB(DWS) Import Performance?
-
Account, Password, and Permission
- How Does GaussDB(DWS) Implement Workload Isolation?
- How Do I Change the Password of a Database Account When the Password Expires?
- How Do I Grant Table Permissions to a User?
- How Do I Grant Schema Permissions to a User?
- How Do I Create a Database Read-only User?
- How Do I Create Private Database Users and Tables?
- How Do I Revoke the CONNECT ON DATABASE Permission from a User?
- How Do I View the Table Permissions of a User?
- Who Is User Ruby?
-
Database Performance
- Why Is SQL Execution Slow After Long GaussDB(DWS) Usage?
- Why Does GaussDB(DWS) Perform Worse Than a Single-Server Database in Extreme Scenarios?
- How Can I View SQL Execution Records in a Certain Period When Read and Write Requests Are Blocked?
- What Do I Do If My Cluster Is Unavailable Because of Insufficient Space?
- GaussDB(DWS) CPU Resource Management
- Why the Tasks Executed by an Ordinary User Are Slower Than That Executed by the dbadmin User?
- What Are the Factors Related to the Single-Table Query Performance in GaussDB(DWS)?
- Snapshot Backup and Restoration
-
General Problems
- API Reference (Paris Region)
-
Developer Guide (Paris Region)
- Welcome
- System Overview
-
Data Migration
- Data Migration to GaussDB(DWS)
-
Data Import
- Importing Data from OBS in Parallel
- Using GDS to Import Data from a Remote Server
- Importing Data from MRS to a Cluster
- Importing Data from One GaussDB(DWS) Cluster to Another
- Using a gsql Meta-Command to Import Data
- Running the COPY FROM STDIN Statement to Import Data
- Full Database Migration
- Meta-command Migration
- Data Export
- Other Operations
- Syntax Compatibility Differences Among Oracle, Teradata, and MySQL
- Database Security Management
- Development and Design Proposal
-
Guide: JDBC- or ODBC-Based Development
- Development Specifications
- Downloading Drivers
-
JDBC-Based Development
- JDBC Package and Driver Class
- Development Process
- Loading a Driver
- Connecting to a Database
- Executing SQL Statements
- Processing Data in a Result Set
- Closing the Connection
- Example: Common Operations
- Example: Retrying SQL Queries for Applications
- Example: Importing and Exporting Data Through Local Files
- Example: Migrating Data from MySQL to GaussDB(DWS)
-
JDBC Interface Reference
- java.sql.Connection
- java.sql.CallableStatement
- java.sql.DatabaseMetaData
- java.sql.Driver
- java.sql.PreparedStatement
- java.sql.ResultSet
- java.sql.ResultSetMetaData
- java.sql.Statement
- javax.sql.ConnectionPoolDataSource
- javax.sql.DataSource
- javax.sql.PooledConnection
- javax.naming.Context
- javax.naming.spi.InitialContextFactory
- CopyManager
- ODBC-Based Development
- PostGIS Extension
- Resource Load Management
- Resource Monitoring
-
Query Performance Optimization
- Overview of Query Performance Optimization
- Query Analysis
- Query Improvement
-
Optimization Cases
- Case: Selecting an Appropriate Distribution Column
- Case: Creating an Appropriate Index
- Case: Adding NOT NULL for JOIN Columns
- Case: Pushing Down Sort Operations to DNs
- Case: Configuring cost_param for Better Query Performance
- Case: Adjusting the Distribution Key
- Case: Adjusting the Partial Clustering Key
- Case: Adjusting the Table Storage Mode in a Medium Table
- Case: Adjusting the Local Clustering Column
- Case: Reconstructing Partition Tables
- Case: Adjusting the GUC Parameter best_agg_plan
- Case: Rewriting SQL and Deleting Subqueries (Case 1)
- Case: Rewriting SQL and Deleting Subqueries (Case 2)
- Case: Rewriting SQL Statements and Eliminating Prune Interference
- Case: Rewriting SQL Statements and Deleting in-clause
- Case: Setting Partial Cluster Keys
- SQL Execution Troubleshooting
- Common Performance Parameter Optimization Design
- User-Defined Functions
- Stored Procedures
-
System Catalogs and System Views
- Overview of System Catalogs and System Views
-
System Catalogs
- GS_OBSSCANINFO
- GS_WLM_INSTANCE_HISTORY
- GS_WLM_OPERATOR_INFO
- GS_WLM_SESSION_INFO
- GS_WLM_USER_RESOURCE_HISTORY
- PG_AGGREGATE
- PG_AM
- PG_AMOP
- PG_AMPROC
- PG_ATTRDEF
- PG_ATTRIBUTE
- PG_AUTHID
- PG_AUTH_HISTORY
- PG_AUTH_MEMBERS
- PG_CAST
- PG_CLASS
- PG_COLLATION
- PG_CONSTRAINT
- PG_CONVERSION
- PG_DATABASE
- PG_DB_ROLE_SETTING
- PG_DEFAULT_ACL
- PG_DEPEND
- PG_DESCRIPTION
- PG_ENUM
- PG_EXTENSION
- PG_EXTENSION_DATA_SOURCE
- PG_FOREIGN_DATA_WRAPPER
- PG_FOREIGN_SERVER
- PG_FOREIGN_TABLE
- PG_INDEX
- PG_INHERITS
- PG_JOBS
- PG_LANGUAGE
- PG_LARGEOBJECT
- PG_LARGEOBJECT_METADATA
- PG_NAMESPACE
- PG_OBJECT
- PG_OBSSCANINFO
- PG_OPCLASS
- PG_OPERATOR
- PG_OPFAMILY
- PG_PARTITION
- PG_PLTEMPLATE
- PG_PROC
- PG_RANGE
- PG_REDACTION_COLUMN
- PG_REDACTION_POLICY
- PG_RLSPOLICY
- PG_RESOURCE_POOL
- PG_REWRITE
- PG_SECLABEL
- PG_SHDEPEND
- PG_SHDESCRIPTION
- PG_SHSECLABEL
- PG_STATISTIC
- PG_STATISTIC_EXT
- PG_SYNONYM
- PG_TABLESPACE
- PG_TRIGGER
- PG_TS_CONFIG
- PG_TS_CONFIG_MAP
- PG_TS_DICT
- PG_TS_PARSER
- PG_TS_TEMPLATE
- PG_TYPE
- PG_USER_MAPPING
- PG_USER_STATUS
- PG_WORKLOAD_ACTION
- PGXC_CLASS
- PGXC_GROUP
- PGXC_NODE
-
System Views
- ALL_ALL_TABLES
- ALL_CONSTRAINTS
- ALL_CONS_COLUMNS
- ALL_COL_COMMENTS
- ALL_DEPENDENCIES
- ALL_IND_COLUMNS
- ALL_IND_EXPRESSIONS
- ALL_INDEXES
- ALL_OBJECTS
- ALL_PROCEDURES
- ALL_SEQUENCES
- ALL_SOURCE
- ALL_SYNONYMS
- ALL_TAB_COLUMNS
- ALL_TAB_COMMENTS
- ALL_TABLES
- ALL_USERS
- ALL_VIEWS
- DBA_DATA_FILES
- DBA_USERS
- DBA_COL_COMMENTS
- DBA_CONSTRAINTS
- DBA_CONS_COLUMNS
- DBA_IND_COLUMNS
- DBA_IND_EXPRESSIONS
- DBA_IND_PARTITIONS
- DBA_INDEXES
- DBA_OBJECTS
- DBA_PART_INDEXES
- DBA_PART_TABLES
- DBA_PROCEDURES
- DBA_SEQUENCES
- DBA_SOURCE
- DBA_SYNONYMS
- DBA_TAB_COLUMNS
- DBA_TAB_COMMENTS
- DBA_TAB_PARTITIONS
- DBA_TABLES
- DBA_TABLESPACES
- DBA_TRIGGERS
- DBA_VIEWS
- DUAL
- GLOBAL_REDO_STAT
- GLOBAL_REL_IOSTAT
- GLOBAL_STAT_DATABASE
- GLOBAL_WORKLOAD_SQL_COUNT
- GLOBAL_WORKLOAD_SQL_ELAPSE_TIME
- GLOBAL_WORKLOAD_TRANSACTION
- GS_ALL_CONTROL_GROUP_INFO
- GS_CLUSTER_RESOURCE_INFO
- GS_INSTR_UNIQUE_SQL
- GS_REL_IOSTAT
- GS_NODE_STAT_RESET_TIME
- GS_SESSION_CPU_STATISTICS
- GS_SESSION_MEMORY_STATISTICS
- GS_SQL_COUNT
- GS_WAIT_EVENTS
- GS_WLM_OPERAROR_INFO
- GS_WLM_OPERATOR_HISTORY
- GS_WLM_OPERATOR_STATISTICS
- GS_WLM_SESSION_INFO
- GS_WLM_SESSION_HISTORY
- GS_WLM_SESSION_STATISTICS
- GS_WLM_SQL_ALLOW
- GS_WORKLOAD_SQL_COUNT
- GS_WORKLOAD_SQL_ELAPSE_TIME
- GS_WORKLOAD_TRANSACTION
- GS_STAT_DB_CU
- GS_STAT_SESSION_CU
- GS_TOTAL_NODEGROUP_MEMORY_DETAIL
- GS_USER_TRANSACTION
- GS_VIEW_DEPENDENCY
- GS_VIEW_DEPENDENCY_PATH
- GS_VIEW_INVALID
- PG_AVAILABLE_EXTENSION_VERSIONS
- PG_AVAILABLE_EXTENSIONS
- PG_BULKLOAD_STATISTICS
- PG_COMM_CLIENT_INFO
- PG_COMM_DELAY
- PG_COMM_STATUS
- PG_COMM_RECV_STREAM
- PG_COMM_SEND_STREAM
- PG_CONTROL_GROUP_CONFIG
- PG_CURSORS
- PG_EXT_STATS
- PG_GET_INVALID_BACKENDS
- PG_GET_SENDERS_CATCHUP_TIME
- PG_GROUP
- PG_INDEXES
- PG_JOB
- PG_JOB_PROC
- PG_JOB_SINGLE
- PG_LIFECYCLE_DATA_DISTRIBUTE
- PG_LOCKS
- PG_NODE_ENV
- PG_OS_THREADS
- PG_POOLER_STATUS
- PG_PREPARED_STATEMENTS
- PG_PREPARED_XACTS
- PG_QUERYBAND_ACTION
- PG_REPLICATION_SLOTS
- PG_ROLES
- PG_RULES
- PG_RUNNING_XACTS
- PG_SECLABELS
- PG_SESSION_WLMSTAT
- PG_SESSION_IOSTAT
- PG_SETTINGS
- PG_SHADOW
- PG_SHARED_MEMORY_DETAIL
- PG_STATS
- PG_STAT_ACTIVITY
- PG_STAT_ALL_INDEXES
- PG_STAT_ALL_TABLES
- PG_STAT_BAD_BLOCK
- PG_STAT_BGWRITER
- PG_STAT_DATABASE
- PG_STAT_DATABASE_CONFLICTS
- PG_STAT_GET_MEM_MBYTES_RESERVED
- PG_STAT_USER_FUNCTIONS
- PG_STAT_USER_INDEXES
- PG_STAT_USER_TABLES
- PG_STAT_REPLICATION
- PG_STAT_SYS_INDEXES
- PG_STAT_SYS_TABLES
- PG_STAT_XACT_ALL_TABLES
- PG_STAT_XACT_SYS_TABLES
- PG_STAT_XACT_USER_FUNCTIONS
- PG_STAT_XACT_USER_TABLES
- PG_STATIO_ALL_INDEXES
- PG_STATIO_ALL_SEQUENCES
- PG_STATIO_ALL_TABLES
- PG_STATIO_SYS_INDEXES
- PG_STATIO_SYS_SEQUENCES
- PG_STATIO_SYS_TABLES
- PG_STATIO_USER_INDEXES
- PG_STATIO_USER_SEQUENCES
- PG_STATIO_USER_TABLES
- PG_THREAD_WAIT_STATUS
- PG_TABLES
- PG_TIMEZONE_ABBREVS
- PG_TIMEZONE_NAMES
- PG_TOTAL_MEMORY_DETAIL
- PG_TOTAL_SCHEMA_INFO
- PG_TOTAL_USER_RESOURCE_INFO
- PG_USER
- PG_USER_MAPPINGS
- PG_VIEWS
- PG_WLM_STATISTICS
- PGXC_BULKLOAD_PROGRESS
- PGXC_BULKLOAD_STATISTICS
- PGXC_COMM_CLIENT_INFO
- PGXC_COMM_DELAY
- PGXC_COMM_RECV_STREAM
- PGXC_COMM_SEND_STREAM
- PGXC_COMM_STATUS
- PGXC_DEADLOCK
- PGXC_GET_STAT_ALL_TABLES
- PGXC_GET_STAT_ALL_PARTITIONS
- PGXC_GET_TABLE_SKEWNESS
- PGXC_GTM_SNAPSHOT_STATUS
- PGXC_INSTANCE_TIME
- PGXC_INSTR_UNIQUE_SQL
- PGXC_LOCK_CONFLICTS
- PGXC_NODE_ENV
- PGXC_NODE_STAT_RESET_TIME
- PGXC_OS_RUN_INFO
- PGXC_OS_THREADS
- PGXC_PREPARED_XACTS
- PGXC_REDO_STAT
- PGXC_REL_IOSTAT
- PGXC_REPLICATION_SLOTS
- PGXC_RUNNING_XACTS
- PGXC_SETTINGS
- PGXC_STAT_ACTIVITY
- PGXC_STAT_BAD_BLOCK
- PGXC_STAT_BGWRITER
- PGXC_STAT_DATABASE
- PGXC_STAT_REPLICATION
- PGXC_SQL_COUNT
- PGXC_THREAD_WAIT_STATUS
- PGXC_TOTAL_MEMORY_DETAIL
- PGXC_TOTAL_SCHEMA_INFO
- PGXC_TOTAL_SCHEMA_INFO_ANALYZE
- PGXC_USER_TRANSACTION
- PGXC_VARIABLE_INFO
- PGXC_WAIT_EVENTS
- PGXC_WLM_OPERATOR_HISTORY
- PGXC_WLM_OPERATOR_INFO
- PGXC_WLM_OPERATOR_STATISTICS
- PGXC_WLM_SESSION_INFO
- PGXC_WLM_SESSION_HISTORY
- PGXC_WLM_SESSION_STATISTICS
- PGXC_WLM_WORKLOAD_RECORDS
- PGXC_WORKLOAD_SQL_COUNT
- PGXC_WORKLOAD_SQL_ELAPSE_TIME
- PGXC_WORKLOAD_TRANSACTION
- PLAN_TABLE
- PLAN_TABLE_DATA
- PV_FILE_STAT
- PV_INSTANCE_TIME
- PV_OS_RUN_INFO
- PV_SESSION_MEMORY
- PV_SESSION_MEMORY_DETAIL
- PV_SESSION_STAT
- PV_SESSION_TIME
- PV_TOTAL_MEMORY_DETAIL
- PV_REDO_STAT
- REDACTION_COLUMNS
- REDACTION_POLICIES
- USER_COL_COMMENTS
- USER_CONSTRAINTS
- USER_CONS_COLUMNS
- USER_INDEXES
- USER_IND_COLUMNS
- USER_IND_EXPRESSIONS
- USER_IND_PARTITIONS
- USER_JOBS
- USER_OBJECTS
- USER_PART_INDEXES
- USER_PART_TABLES
- USER_PROCEDURES
- USER_SEQUENCES
- USER_SOURCE
- USER_SYNONYMS
- USER_TAB_COLUMNS
- USER_TAB_COMMENTS
- USER_TAB_PARTITIONS
- USER_TABLES
- USER_TRIGGERS
- USER_VIEWS
- V$SESSION
- V$SESSION_LONGOPS
-
GUC Parameters
- Viewing GUC Parameters
- Configuring GUC Parameters
- GUC Parameter Usage
- Connection and Authentication
- Resource Consumption
- Parallel Data Import
- Write Ahead Logs
- HA Replication
- Query Planning
- Error Reporting and Logging
- Alarm Detection
- Statistics During the Database Running
- Workload Management
- Automatic Cleanup
- Default Settings of Client Connection
- Lock Management
- Version and Platform Compatibility
- Fault Tolerance
- Connection Pool Parameters
- Cluster Transaction Parameters
- Developer Operations
- Auditing
- Transaction Monitoring
- Miscellaneous Parameters
- Glossary
-
SQL Syntax Reference (Paris Region)
- GaussDB(DWS) SQL
- Differences Between GaussDB(DWS) and PostgreSQL
- Keyword
- Data Types
- Constant and Macro
-
Functions and Operators
- Logical Operators
- Comparison Operators
- Character Processing Functions and Operators
- Binary String Functions and Operators
- Bit String Functions and Operators
- Pattern Matching Operators
- Mathematical Functions and Operators
- Date and Time Processing Functions and Operators
- Type Conversion Functions
- Geometric Functions and Operators
- Network Address Functions and Operators
- Text Search Functions and Operators
- UUID Functions
- JSON Functions
- HLL Functions and Operators
- SEQUENCE Functions
- Array Functions and Operators
- Range Functions and Operators
- Aggregate Functions
- Window Functions
- Security Functions
- Set Returning Functions
- Conditional Expression Functions
- System Information Functions
-
System Administration Functions
- Configuration Settings Functions
- Universal File Access Functions
- Server Signaling Functions
- Backup and Restoration Control Functions
- Snapshot Synchronization Functions
- Database Object Functions
- Advisory Lock Functions
- Residual File Management Functions
- Replication Functions
- Other Functions
- Resource Management Functions
- Data Redaction Functions
- Statistics Information Functions
- Trigger Functions
- XML Functions
- Call Stack Recording Functions
- Expressions
- Type Conversion
- Full Text Search
- System Operation
- Controlling Transactions
-
DDL Syntax
- DDL Syntax Overview
- ALTER DATABASE
- ALTER FOREIGN TABLE (for GDS)
- ALTER FOREIGN TABLE (for HDFS or OBS)
- ALTER FUNCTION
- ALTER GROUP
- ALTER INDEX
- ALTER LARGE OBJECT
- ALTER REDACTION POLICY
- ALTER RESOURCE POOL
- ALTER ROLE
- ALTER ROW LEVEL SECURITY POLICY
- ALTER SCHEMA
- ALTER SEQUENCE
- ALTER SERVER
- ALTER SESSION
- ALTER SYNONYM
- ALTER SYSTEM KILL SESSION
- ALTER TABLE
- ALTER TABLE PARTITION
- ALTER TEXT SEARCH CONFIGURATION
- ALTER TEXT SEARCH DICTIONARY
- ALTER TRIGGER
- ALTER TYPE
- ALTER USER
- ALTER VIEW
- CLEAN CONNECTION
- CLOSE
- CLUSTER
- COMMENT
- CREATE BARRIER
- CREATE DATABASE
- CREATE FOREIGN TABLE (for GDS Import and Export)
- CREATE FOREIGN TABLE (SQL on OBS or Hadoop )
- CREATE FOREIGN TABLE (for OBS Import and Export)
- CREATE FUNCTION
- CREATE GROUP
- CREATE INDEX
- CREATE REDACTION POLICY
- CREATE ROW LEVEL SECURITY POLICY
- CREATE PROCEDURE
- CREATE RESOURCE POOL
- CREATE ROLE
- CREATE SCHEMA
- CREATE SEQUENCE
- CREATE SERVER
- CREATE SYNONYM
- CREATE TABLE
- CREATE TABLE AS
- CREATE TABLE PARTITION
- CREATE TABLESPACE
- CREATE TEXT SEARCH CONFIGURATION
- CREATE TEXT SEARCH DICTIONARY
- CREATE TRIGGER
- CREATE TYPE
- CREATE USER
- CREATE VIEW
- CURSOR
- DROP DATABASE
- DROP FOREIGN TABLE
- DROP FUNCTION
- DROP GROUP
- DROP INDEX
- DROP OWNED
- DROP REDACTION POLICY
- DROP ROW LEVEL SECURITY POLICY
- DROP PROCEDURE
- DROP RESOURCE POOL
- DROP ROLE
- DROP SCHEMA
- DROP SEQUENCE
- DROP SERVER
- DROP SYNONYM
- DROP TABLE
- DROP TABLESPACE
- DROP TEXT SEARCH CONFIGURATION
- DROP TEXT SEARCH DICTIONARY
- DROP TRIGGER
- DROP TYPE
- DROP USER
- DROP VIEW
- FETCH
- MOVE
- REINDEX
- RESET
- SET
- SET CONSTRAINTS
- SET ROLE
- SET SESSION AUTHORIZATION
- SHOW
- TRUNCATE
- VACUUM
- DML Syntax
- DCL Syntax
- DQL Syntax
- TCL Syntax
- GIN Indexes
-
Tool Guide (Paris Region)
- Overview
- Downloading Client Tools
- gsql - CLI Client
-
Data Studio - Integrated Database Development Tool
- About Data Studio
- Installing and Configuring Data Studio
- Quick Start
- Data Studio GUI
- Data Studio Menus
- Data Studio Toolbar
- Data Studio Right-Click Menus
- Connection Profiles
- Databases
- Schemas
- Creating a Function/Procedure
- Editing a Function/Procedure
- Granting/Revoking a Permission (Function/Procedure)
- Debugging a PL/SQL Function
- Working with Functions/Procedures
- GaussDB(DWS) Tables
- Sequences
- Views
-
SQL Terminal
- Opening Multiple SQL Terminal Tabs
- Managing the History of Executed SQL Queries
- Opening and Saving SQL Scripts
- Viewing Object Properties in the SQL Terminal
- Canceling the Execution of SQL Queries
- Formatting of SQL Queries
- Selecting a DB Object in the SQL Terminal
- Viewing the Execution Plan and Costs
- Viewing the Query Execution Plan and Cost Graphically
- Using SQL Terminals
- Exporting Query Results
- Managing SQL Terminal Connections
- Batch Operation
- Personalizing Data Studio
- Performance Specifications
- Security Management
- Troubleshooting
- FAQs
- GDS: Parallel Data Loader
-
DSC: SQL Syntax Migration Tool
- Overview
- Supported Keywords and Features
- Constraints and Limitations
- System Requirements
- Installing DSC
- Configuring DSC
- Using DSC
- Teradata Syntax Migration
-
Oracle Syntax Migration
- Overview
- Schema Objects
- COMPRESS Phrase
- Bitmap Index
- Custom Tablespace
- Supplemental Log Data
- LONG RAW
- DML
- Pseudo Columns
- OUTER JOIN
- OUTER QUERY (+)
- CONNECT BY
- System Functions
- PL/SQL
- PL/SQL Collections (Using User-Defined Types)
- PL/SQL Packages
- VARRAY
- Granting Execution Permissions
- Package Name List
- Data Type
- Chinese Character Support
- Netezza Syntax Migration
- MySQL Syntax Migration
- DB2 Syntax Migration
- Command Reference
- Log Reference
- Troubleshooting
- FAQs
- Security Management
- Server Tool
- Change History
- Error Code Reference (Paris Region)
-
User Guide (Kuala Lumpur Region)
- Service Overview
- Getting Started
- Process for Using GaussDB(DWS)
- Preparations
- Cluster Configuration
-
Cluster Connection
- Methods of Connecting to a Cluster
- Obtaining the Cluster Connection Address
- Using the gsql CLI Client to Connect to a Cluster
- Using the Data Studio GUI Client to Connect to a Cluster
- Using the JDBC and ODBC Drivers to Connect to a Cluster
- Using the Python Library psycopg2 to Connect to a Cluster
- Using the Python Library PyGreSQL to Connect to a Cluster
- Managing Database Connections
-
Clusters
- Checking the Cluster Status
- Viewing Basic Cluster Information
- Managing Access Domain Names
- Nodes
- Cluster Scale-out
- Cluster Redistribution
- Performing a Primary/Standby Switchback
- Cluster Upgrade
- Password Reset
- Cluster Restart
- Modifying Database Parameters
- MRS Data Sources
- Managing Cluster Workloads
- Managing Logical Clusters
- Managing Tags
- Deleting Clusters
- Managing Parameter Templates
- Managing Clusters That Fail to Be Created
- Read-only Status
- Cluster HA
- Monitoring and Alarms
- Cluster Security Management
- Audit Logs
-
FAQs
-
General Problems
- Why Are Data Warehouses Necessary?
- What Are the Differences Between a Data Warehouse and the Hadoop Big Data Platform?
- Why Should I Use GaussDB(DWS)?
- When Should I Use GaussDB(DWS) and MRS?
- What Are the Differences Between GaussDB(DWS) and Hive in Functions?
- What Is the User Quota?
- What Are the Differences Between Users and Roles?
- How Do I Check the Creation Time of a Database User?
- Regions and AZs
- Is My Data Secure in GaussDB(DWS)?
- How Is GaussDB(DWS) Secured?
- Can I Modify the Security Group of a GaussDB(DWS) Cluster?
- What Is a Database/Data Warehouse/Data Lake/Lakehouse?
-
Cluster Management
- What Do I Do If Creating a GaussDB(DWS) Cluster Failed?
- How Can I Clear and Reclaim the Storage Space?
- Why Did the Used Storage Shrink After Scale-out?
- How Do I View Node Metrics (CPU, Memory, and Disk Usage)?
- Does GaussDB(DWS) Support a Single Node for a Learning Environment?
- How Is the Disk Space or Capacity of GaussDB(DWS) Calculated?
- What Are the gaussdb and postgres Databases of GaussDB(DWS)?
- How Do I Set the Maximum Number of Sessions When Adding an Alarm Rule on Cloud Eye?
- When Should I Add CNs or Scale out a cluster?
- What Are the Differences Between Hot Data Storage and Cold Data Storage?
-
Database Connections
- How Applications Communicate with GaussDB(DWS)?
- Does GaussDB(DWS) Support Third-Party Clients and JDBC and ODBC Drivers?
- Can I Connect to GaussDB(DWS) Cluster Nodes Using SSH?
- What Should I Do If I Cannot Connect to a Data Warehouse Cluster?
- Why Was I Not Notified of Failure Unbinding the EIP When GaussDB(DWS) Is Connected Over the Internet?
- How Do I Configure a Whitelist to Protect Clusters Available Through a Public IP Address?
-
Data Import and Export
- What Are the Differences Between Data Formats Supported by OBS and GDS Foreign Tables?
- How Do I Import Incremental Data Using an OBS Foreign Table?
- How Can I Import Data to GaussDB(DWS)?
- How Much Service Data Can a Data Warehouse Store?
- How Do I Use \Copy to Import and Export Data?
- Can I Export GaussDB(DWS) Data from/to OBS Across Regions?
- How Do I Import GaussDB(DWS)/Oracle/MySQL/SQL Server Data to GaussDB(DWS) (Whole Database Migration)?
- Can I Import Data over the Public/External Network Using GDS?
- Which Are the Factors That Affect GaussDB(DWS) Import Performance?
-
Account, Password, and Permissions
- How Does GaussDB(DWS) Implement Workload Isolation?
- How Do I Change the Password of a Database Account When the Password Expires?
- How Do I Grant Table Permissions to a User?
- How Do I Grant Schema Permissions to a User?
- How Do I Create a Database Read-only User?
- How Do I Create Private Database Users and Tables?
- How Do I Revoke the CONNECT ON DATABASE Permission from a User?
- How Do I View the Table Permissions of a User?
- Who Is User Ruby?
-
Database Usage
- How Do I Change Distribution Columns?
- How Do I View and Set the Database Character Encoding?
- What Do I Do If Date Type Is Automatically Converted to the Timestamp Type During Table Creation?
- Do I Need to Run VACUUM FULL and ANALYZE on Common Tables Periodically?
- Do I Need to Set a Distribution Key After Setting a Primary Key?
- Is GaussDB(DWS) Compatible with PostgreSQL Stored Procedures?
- What Are Partitioned Tables, Partitions, and Partition Keys?
- How Can I Export the Table Structure?
- How Can I Export All Tables and Views from a Database?
- How Can I Delete Table Data Efficiently?
- How Do I View Foreign Table Information?
- If No Distribution Column Is Specified, How Will Data Be Stored?
- How Do I Replace the Null Result with 0?
- How Do I Check Whether a Table Is Row-Stored or Column-Stored?
- How Do I Query the Information About GaussDB(DWS) Column-Store Tables?
- Why Sometimes the GaussDB(DWS) Query Indexes Become Invalid?
- How Do I Use a User-Defined Function to Rewrite the CRC32() Function?
- What Are the Schemas Starting with pg_toast_temp* or pg_temp*?
- Solutions to Inconsistent GaussDB(DWS) Query Results
- Which System Catalogs That the VACUUM FULL Operation Cannot Be Performed on?
- In Which Scenarios Would a Statement Be "idle in transaction"?
-
Database Performance
- Why Is SQL Execution Slow After Long GaussDB(DWS) Usage?
- Why Does GaussDB(DWS) Perform Worse Than a Single-Server Database in Extreme Scenarios?
- How Can I View SQL Execution Records in a Certain Period When Read and Write Requests Are Blocked?
- What Do I Do If My Cluster Is Unavailable Because of Insufficient Space?
- Snapshot Backup and Restoration
-
General Problems
- Change History
- API Reference (Kuala Lumpur Region)
-
Developer Guide (Kuala Lumpur Region)
- Welcome
- System Overview
-
Data Migration
- Data Migration to GaussDB(DWS)
-
Data Import
- Importing Data from OBS in Parallel
- Using GDS to Import Data from a Remote Server
- Importing Data from MRS to a Cluster
- Importing Data from One GaussDB(DWS) Cluster to Another
- Using the gsql Meta-Command \COPY to Import Data
- Running the COPY FROM STDIN Statement to Import Data
- Full Database Migration
- Metadata Migration
- Data Export
- Other Operations
- Syntax Compatibility Differences Among Oracle, Teradata, and MySQL
- Database Security Management
- Development and Design Proposal
-
Guide: JDBC- or ODBC-Based Development
- Development Specifications
- Downloading Drivers
-
JDBC-Based Development
- JDBC Package and Driver Class
- Development Process
- Loading a Driver
- Connecting to a Database
- Executing SQL Statements
- Processing Data in a Result Set
- Closing the Connection
- Example: Common Operations
- Example: Retrying SQL Queries for Applications
- Example: Importing and Exporting Data Through Local Files
- Example: Migrating Data from MySQL to GaussDB(DWS)
-
JDBC Interface Reference
- java.sql.Connection
- java.sql.CallableStatement
- java.sql.DatabaseMetaData
- java.sql.Driver
- java.sql.PreparedStatement
- java.sql.ResultSet
- java.sql.ResultSetMetaData
- java.sql.Statement
- javax.sql.ConnectionPoolDataSource
- javax.sql.DataSource
- javax.sql.PooledConnection
- javax.naming.Context
- javax.naming.spi.InitialContextFactory
- CopyManager
- ODBC-Based Development
- PostGIS Extension
- Resource Load Management
- Resource Monitoring
-
Query Performance Optimization
- Overview of Query Performance Optimization
- Query Analysis
- Query Improvement
-
Optimization Cases
- Case: Selecting an Appropriate Distribution Column
- Case: Creating an Appropriate Index
- Case: Adding NOT NULL for JOIN Columns
- Case: Pushing Down Sort Operations to DNs
- Case: Configuring cost_param for Better Query Performance
- Case: Adjusting the Distribution Key
- Case: Adjusting the Partial Clustering Key
- Case: Adjusting the Table Storage Mode in a Medium Table
- Case: Adjusting the Local Clustering Column
- Case: Reconstructing Partition Tables
- Case: Adjusting the GUC Parameter best_agg_plan
- Case: Rewriting SQL and Deleting Subqueries (Case 1)
- Case: Rewriting SQL and Deleting Subqueries (Case 2)
- Case: Rewriting SQL Statements and Eliminating Prune Interference
- Case: Rewriting SQL Statements and Deleting in-clause
- Case: Setting Partial Cluster Keys
- SQL Execution Troubleshooting
- Common Performance Parameter Optimization Design
- User-Defined Functions
- Stored Procedures
-
System Catalogs and System Views
- Overview of System Catalogs and System Views
-
System Catalogs
- GS_OBSSCANINFO
- GS_WLM_INSTANCE_HISTORY
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Copied.
SELECT
Function
SELECT retrieves data from a table or view.
Serving as an overlaid filter for a database table, SELECT using SQL keywords retrieves required data from data tables.
Precautions
- Using SELECT can join HDFS and ordinary tables, but cannot join ordinary and GDS foreign tables. That is, a SELECT statement cannot contain both ordinary and GDS foreign tables.
- The user must have the SELECT permission on every column used in the SELECT command.
- UPDATE permission is required when using FOR UPDATE or FOR SHARE.
Syntax
- Querying data
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[ WITH [ RECURSIVE ] with_query [, ...] ] SELECT [/*+ plan_hint */] [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ] { * | {expression [ [ AS ] output_name ]} [, ...] } [ FROM from_item [, ...] ] [ WHERE condition ] [ GROUP BY grouping_element [, ...] ] [ HAVING condition [, ...] ] [ WINDOW {window_name AS ( window_definition )} [, ...] ] [ { UNION | INTERSECT | EXCEPT | MINUS } [ ALL | DISTINCT ] select ] [ ORDER BY {expression [ [ ASC | DESC | USING operator ] | nlssort_expression_clause ] [ NULLS { FIRST | LAST } ]} [, ...] ] [ { [ LIMIT { count | ALL } ] [ OFFSET start [ ROW | ROWS ] ] } | { LIMIT start, { count | ALL } } ] [ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ] [ {FOR { UPDATE | SHARE } [ OF table_name [, ...] ] [ NOWAIT ]} [...] ]; |
In condition and expression, you can use the aliases of expressions in targetlist in compliance with the following rules:
- Reference only in the same level.
- Only reference aliases in targetlist.
- Reference a prior expression in a subsequent expression.
- The volatile function cannot be used.
- The Window function cannot be used.
- Do not reference an alias in the join on condition.
- An error is reported if targetlist contains multiple referenced aliases.
- The subquery with_query is as follows:
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with_query_name [ ( column_name [, ...] ) ] AS ( {select | values | insert | update | delete} )
- The specified query source from_item is as follows:
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{[ ONLY ] table_name [ * ] [ partition_clause ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ] |( select ) [ AS ] alias [ ( column_alias [, ...] ) ] |with_query_name [ [ AS ] alias [ ( column_alias [, ...] ) ] ] |function_name ( [ argument [, ...] ] ) [ AS ] alias [ ( column_alias [, ...] | column_definition [, ...] ) ] |function_name ( [ argument [, ...] ] ) AS ( column_definition [, ...] ) |from_item [ NATURAL ] join_type from_item [ ON join_condition | USING ( join_column [, ...] ) ]}
- The group clause is as follows:
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( ) | expression | ( expression [, ...] ) | ROLLUP ( { expression | ( expression [, ...] ) } [, ...] ) | CUBE ( { expression | ( expression [, ...] ) } [, ...] ) | GROUPING SETS ( grouping_element [, ...] )
- The specified partition partition_clause is as follows:
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PARTITION { ( partition_name ) | FOR ( partition_value [, ...] ) }
NOTE:
Partitions can be specified only for ordinary tables.
- The sorting order nlssort_expression_clause is as follows:
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NLSSORT ( column_name, ' NLS_SORT = { SCHINESE_PINYIN_M | generic_m_ci } ' )
- Simplified query syntax, equivalent to select * from table_name.
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TABLE { ONLY {(table_name)| table_name} | table_name [ * ]};
Parameter Description
- WITH [ RECURSIVE ] with_query [, ...]
The WITH clause allows you to specify one or more subqueries that can be referenced by name in the primary query, equal to temporary table.
If RECURSIVE is specified, it allows a SELECT subquery to reference itself by name.
The detailed format of with_query is as follows: with_query_name [ ( column_name [, ...] ) ] AS ( {select | values | insert | update | delete} )
- with_query_name specifies the name of the result set generated by a subquery. Such names can be used to access the result sets of subqueries in a query.
- column_name specifies a column name displayed in the subquery result set.
- Each subquery can be a SELECT, VALUES, INSERT, UPDATE or DELETE statement.
- plan_hint clause
Follows the SELECT keyword in the /*+<Plan hint> */ format. It is used to optimize the plan of a SELECT statement block. For details, see section "Hint-based Tuning."
- ALL
Specifies that all rows meeting the requirements are returned. This is the default behavior, so you can omit this keyword.
- DISTINCT [ ON ( expression [, ...] ) ]
Removes all duplicate rows from the SELECT result set.
ON ( expression [, ...] ) is only reserved for the first row among all the rows with the same result calculated using given expressions.
NOTICE:
DISTINCT ON expression is explained with the same rule of ORDER BY. Unless you use ORDER BY to guarantee that the required row appears first, you cannot know what the first row is.
- SELECT list
Indicates columns to be queried. Some or all columns (using wildcard character *) can be queried.
You may use the AS output_name clause to give an alias for an output column. The alias is used for the displaying of the output column.
Column names may be either of:
- Manually input column names which are spaced using commas (,).
- Fields computed in the FROM clause.
- FROM clause
Indicates one or more source tables for SELECT.
The FROM clause can contain the following elements:
- table_name
Indicates the name (optionally schema-qualified) of an existing table or view, for example, schema_name.table_name.
- alias
Gives a temporary alias to a table to facilitate the quotation by other queries.
An alias is used for brevity or to eliminate ambiguity for self-joins. When an alias is provided, it completely hides the actual name of the table or function.
- column_alias
- PARTITION
Queries data in the specified partition of a partitioned table.
- partition_name
- partition_value
Specifies the value of the specified partition key. If there are many partition keys, use the PARTITION FOR clause to specify the value of the only partition key you want to use.
- subquery
Performs a subquery in the FROM clause. A temporary table is created to save subquery results.
- with_query_name
WITH clause can also be the source of FROM clause and can be referenced with the name queried by executing WITH.
- function_name
Function name. Function calls can appear in the FROM clause.
- join_type
- [ INNER ] JOIN
A JOIN clause combines two FROM items. Use parentheses if necessary to determine the order of nesting. In the absence of parentheses, JOIN nests left-to-right.
In any case, JOIN binds more tightly than the commas separating FROM items.
- LEFT [ OUTER ] JOIN
Returns all rows in the qualified Cartesian product (all combined rows that pass its join condition), and pluses one copy of each row in the left-hand table for which there was no right-hand row that passed the join condition. This left-hand row is extended to the full width of the joined table by inserting NULL values for the right-hand columns. Note that only the JOIN clause's own condition is considered while deciding which rows have matches. Outer conditions are applied afterwards.
- RIGHT [ OUTER ] JOIN
Returns all the joined rows, plus one row for each unmatched right-hand row (extended with NULL on the left).
This is just a notational convenience, since you could convert it to a LEFT OUTER JOIN by switching the left and right inputs.
- FULL [ OUTER ] JOIN
Returns all the joined rows, pluses one row for each unmatched left-hand row (extended with NULL on the right), and pluses one row for each unmatched right-hand row (extended with NULL on the left).
- CROSS JOIN
CROSS JOIN is equivalent to INNER JOIN ON (TRUE), which means no rows are removed by qualification. These join types are just a notational convenience, since they do nothing you could not do with plain FROM and WHERE.
NOTE:
For the INNER and OUTER join types, a join condition must be specified, namely exactly one of NATURAL ON, join_condition, or USING (join_column [, ...]). For CROSS JOIN, none of these clauses can appear.
CROSS JOIN and INNER JOIN produce a simple Cartesian product, the same result as you get from listing the two items at the top level of FROM.
- [ INNER ] JOIN
- ON join_condition
A join condition to define which rows have matches in joins. Example: ON left_table.a = right_table.a
- USING(join_column[, ...])
ON left_table.a = right_table.a AND left_table.b = right_table.b ... abbreviation. Corresponding columns must have the same name.
- NATURAL
NATURAL is a shorthand for a USING list that mentions all columns in the two tables that have the same names.
- from item
- table_name
- WHERE clause
The WHERE clause forms an expression for row selection to narrow down the query range of SELECT. The condition is any expression that evaluates to a result of Boolean type. Rows that do not satisfy this condition will be eliminated from the output.
In the WHERE clause, you can use the operator (+) to convert a table join to an outer join. However, this method is not recommended because it is not the standard SQL syntax and may raise syntax compatibility issues during platform migration. There are many restrictions on using the operator (+):
- It can appear only in the WHERE clause.
- If a table join has been specified in the FROM clause, the operator (+) cannot be used in the WHERE clause.
- The operator (+) can work only on columns of tables or views, instead of on expressions.
- If table A and table B have multiple join conditions, the operator (+) must be specified in all the conditions. Otherwise, the operator (+) will not take effect, and the table join will be converted into an inner join without any prompt information.
- Tables specified in a join condition where the operator (+) works cannot cross queries or subqueries. If tables where the operator (+) works are not in the FROM clause of the current query or subquery, an error will be reported. If a peer table for the operator (+) does not exist, no error will be reported and the table join will be converted into an inner join.
- Expressions where the operator (+) is used cannot be directly connected through OR.
- If a column where the operator (+) works is compared with a constant, the expression becomes a part of the join condition.
- A table cannot have multiple foreign tables.
- The operator (+) can appear only in the following expressions: comparison, NOT, ANY, ALL, IN, NULLIF, IS DISTINCT FROM, and IS OF expressions. It is not allowed in other types of expressions. In addition, these expressions cannot be connected through AND or OR.
- The operator (+) can be used to convert a table join only to a left or right outer join, instead of a full join. That is, the operator (+) cannot be specified on both tables of an expression.
NOTICE:
For the WHERE clause, if a special character % _ or \ is queried in LIKE, add the slash (\) before each character.
Example:
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create table tt01 (id int,content varchar(50)); NOTICE: The 'DISTRIBUTE BY' clause is not specified. Using 'id' as the distribution column by default. HINT: Please use 'DISTRIBUTE BY' clause to specify suitable data distribution column. CREATE TABLE insert into tt01 values (1,'Jack say ''hello'''); INSERT 0 1 insert into tt01 values (2,'Rose do 50%'); INSERT 0 1 insert into tt01 values (3,'Lilei say ''world'''); INSERT 0 1 insert into tt01 values (4,'Hanmei do 100%'); INSERT 0 1 select * from tt01; id | content ----+------------------- 3 | Lilei say 'world' 4 | Hanmei do 100% 1 | Jack say 'hello' 2 | Rose do 50% (4 rows) select * from tt01 where content like '%''he%'; id | content ----+------------------ 1 | Jack say 'hello' (1 row) select * from tt01 where content like '%50\%%'; id | content ----+------------- 2 | Rose do 50% (1 row) drop table tt01; DROP TABLE
- GROUP BY clause
Condenses query results into a single row or selected rows that share the same values for the grouped expressions.
- CUBE ( { expression | ( expression [, ...] ) } [, ...] )
A CUBE grouping is an extension to the GROUP BY clause that creates subtotals for all of the possible combinations of the given list of grouping columns (or expressions). In terms of multidimensional analysis, CUBE generates all the subtotals that could be calculated for a data cube with the specified dimensions. For example, given three expressions (n=3) in the CUBE clause, the operation results in 2n = 23 = 8 groupings. Rows grouped on the values of n expressions are called regular rows, and the rest are called superaggregate rows.
- GROUPING SETS ( grouping_element [, ...] )
GROUPING SETS is another extension to the GROUP BY clause. It allows users to specify multiple GROUP BY clauses. This improves efficiency by trimming away unnecessary data. After you specify the set of groups that you want to create using a GROUPING SETS expression within a GROUP BY clause, the database does not need to compute a whole ROLLUP or CUBE.
NOTICE:
If the SELECT list expression quotes some ungrouped fields and no aggregate function is used, an error is displayed. This is because multiple values may be returned for ungrouped fields.
- CUBE ( { expression | ( expression [, ...] ) } [, ...] )
- HAVING clause
Selects special groups by working with the GROUP BY clause. The HAVING clause compares some attributes of groups with a constant. Only groups that matching the logical expression in the HAVING clause are extracted.
- WINDOW clause
The general format is WINDOW window_name AS ( window_definition ) [, ...]. window_name is a name can be referenced by window_definition. window_definition can be expressed in the following forms:
[ existing_window_name ]
[ PARTITION BY expression [, ...] ]
[ ORDER BY expression [ ASC | DESC | USING operator ] [ NULLS { FIRST | LAST } ] [, ...] ]
[ frame_clause ]
frame_clause defines a window frame for the window function. The window function (not all window functions) depends on window frame and window frame is a set of relevant rows of the current query row. frame_clause can be expressed in the following forms:
[ RANGE | ROWS ] frame_start
[ RANGE | ROWS ] BETWEEN frame_start AND frame_end
frame_start and frame_end can be expressed in the following forms:
UNBOUNDED PRECEDING
value PRECEDING (not supported for RANGE)
CURRENT ROW
value FOLLOWING (not supported for RANGE)
UNBOUNDED FOLLOWING
NOTICE:
For the query of column storage table, only row_number window function is supported, frame_clause is not supported.
- UNION clause
Computes the set union of the rows returned by the involved SELECT statements.
The UNION clause has the following constraints:
- By default, the result of UNION does not contain any duplicate rows unless the ALL option is specified.
- Multiple UNION operators in the same SELECT statement are evaluated left to right, unless otherwise specified by parentheses.
- FOR UPDATE cannot be specified either for a UNION result or for any input of a UNION.
General expression:
select_statement UNION [ALL] select_statement
- select_statement can be any SELECT statement without an ORDER BY, LIMIT, FOR UPDATE, or FOR SHARE statement.
- ORDER BY and LIMIT in parentheses can be attached in a sub-expression.
- INTERSECT clause
Computes the set intersection of rows returned by the involved SELECT statements. The result of INTERSECT does not contain any duplicate rows.
The INTERSECT clause has the following constraints:
- Multiple INTERSECT operators in the same SELECT statement are evaluated left to right, unless otherwise specified by parentheses.
- Processing INTERSECT preferentially when UNION and INTERSECT operations are executed for results of multiple SELECT statements.
General format:
select_statement INTERSECT select_statement
select_statement can be any SELECT statement without a FOR UPDATE clause.
- EXCEPT clause
EXCEPT clause has the following common form:
select_statement EXCEPT [ ALL ] select_statement
select_statement can be any SELECT statement without a FOR UPDATE clause.
The EXCEPT operator computes the set of rows that are in the result of the left SELECT statement but not in the result of the right one.
The result of EXCEPT does not contain any duplicate rows unless the ALL option is specified. To execute ALL, a row that has m duplicates in the left table and n duplicates in the right table will appear MAX(m–n, 0) times in the result set.
Multiple EXCEPT operators in the same SELECT statement are evaluated left to right, unless parentheses dictate otherwise. EXCEPT binds at the same level as UNION.
Currently, FOR UPDATE and FOR SHARE cannot be specified either for an EXCEPT result or for any input of an EXCEPT.
- MINUS clause
Has the same function and syntax as EXCEPT clause.
- ORDER BY clause
Sorts data retrieved by SELECT in descending or ascending order. If the ORDER BY expression contains multiple columns:
- If two columns are equal according to the leftmost expression, they are compared according to the next expression and so on.
- If they are equal according to all specified expressions, they are returned in an implementation-dependent order.
- Columns sorted by ORDER BY must be contained in the result set retrieved by SELECT.
NOTICE:
- If ORDER BY is not specified, the query results are returned following the generation sequence in the database system.
- You can add the keyword ASC (in ascending order) or DESC (in descending order) next to any expression in the ORDER BY clause. If the keyword is not specified, ASC is used by default.
- To sort query results by case-insensitive Chinese pinyin, specify the UTF-8 or GBK encoding mode during database initialization. Run either of the following commands:
initdb –E UTF8 –D ../data –locale=zh_CN.UTF-8 or initdb –E GBK –D ../data –locale=zh_CN.GBK
- [ { [ LIMIT { count | ALL } ] [ OFFSET start [ ROW | ROWS ] ] } | { LIMIT start, { count | ALL } } ]
The LIMIT clause consists of two independent LIMIT clauses, an OFFSET clause, and a LIMIT clause with multiple parameters.
LIMIT { count | ALL }
OFFSET start [ ROW | ROWS ]
LIMIT start, { count | ALL }
count in the clauses specifies the maximum number of rows to return, while start specifies the number of rows to skip before starting to return rows. When both are specified, start rows are skipped before starting to count the count rows to be returned. A multi-parameter LIMIT clause cannot be used together with a single-parameter LIMIT or OFFSET clause.
- FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY
If count is omitted in a FETCH clause, it defaults to 1.
- FOR UPDATE clause
Locks rows retrieved by SELECT. This ensures that the rows cannot be modified or deleted by other transactions until the current transaction ends. That is, other transactions that attempt UPDATE, DELETE, or SELECT FOR UPDATE of these rows will be blocked until the current transaction ends.
To avoid waiting for the committing of other transactions, you can apply NOWAIT. Rows to which NOWAIT applies cannot be immediately locked. After SELECT FOR UPDATE NOWAIT is executed, an error is reported.
FOR SHARE behaves similarly, except that it acquires a shared rather than exclusive lock on each retrieved row. A share lock blocks other transaction from performing UPDATE, DELETE, or SELECT FOR UPDATE on these rows, but it does not prevent them from performing SELECT FOR SHARE.
If specified tables are named in FOR UPDATE or FOR SHARE, then only rows coming from those tables are locked; any other tables used in SELECT are simply read as usual. Otherwise, locking all tables in the command.
If FOR UPDATE or FOR SHARE is applied to a view or sub-query, it affects all tables used in the view or sub-query.
Multiple FOR UPDATE and FOR SHARE clauses can be written if it is necessary to specify different locking behaviors for different tables.
If the same table is mentioned (or implicitly affected) by both FOR UPDATE and FOR SHARE clauses, it is processed as FOR UPDATE. Similarly, a table is processed as NOWAIT if that is specified in any of the clauses affecting it.
NOTICE:
- For SQL statements containing FOR UPDATE or FOR SHARE, their execution plans will be pushed down to DNs. If the pushdown fails, an error will be reported.
- The query of column storage table does not support for update/share.
- NLS_SORT
Indicates a field to be ordered in a special mode. Currently, only the Chinese Pinyin order and case insensitive order are supported.
Valid value:
- SCHINESE_PINYIN_M, sorted by Pinyin order. To use this sort method, specify GBK as the encoding format when you create the database. If you do not do so, this value is invalid.
- generic_m_ci, case-insensitive order.
- PARTITION clause
Queries data in the specified partition of a partitioned table.
Examples
Obtain the temp_t temporary table by a subquery and query all records in this table.
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WITH temp_t(name,isdba) AS (SELECT usename,usesuper FROM pg_user) SELECT * FROM temp_t; |
Query all the r_reason_sk records in the tpcds.reason table and de-duplicate them.
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SELECT DISTINCT(r_reason_sk) FROM tpcds.reason; |
Example of a LIMIT clause: Obtain a record from the table.
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SELECT * FROM tpcds.reason LIMIT 1; |
Example of a LIMIT clause: Obtain the third record from the table.
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SELECT * FROM tpcds.reason LIMIT 1 OFFSET 2; SELECT * FROM tpcds.reason LIMIT 2; |
Query all records and sort them in alphabetic order.
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SELECT r_reason_desc FROM tpcds.reason ORDER BY r_reason_desc; |
Use table aliases to obtain data from the pg_user and pg_user_status tables.
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SELECT a.usename,b.locktime FROM pg_user a,pg_user_status b WHERE a.usesysid=b.roloid; |
Example of the FULL JOIN clause: Join data in the pg_user and pg_user_status tables.
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SELECT a.usename,b.locktime,a.usesuper FROM pg_user a FULL JOIN pg_user_status b on a.usesysid=b.roloid; |
Example of the GROUP BY clause: Filter data based on query conditions, and group the results.
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SELECT r_reason_id, AVG(r_reason_sk) FROM tpcds.reason GROUP BY r_reason_id HAVING AVG(r_reason_sk) > 25; |
Example of the GROUP BY CUBE clause: Filter data based on query conditions, and group the results.
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SELECT r_reason_id,AVG(r_reason_sk) FROM tpcds.reason GROUP BY CUBE(r_reason_id,r_reason_sk); |
Example of the GROUP BY GROUPING SETS clause: Filter data based on query conditions, and group the results.
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SELECT r_reason_id,AVG(r_reason_sk) FROM tpcds.reason GROUP BY GROUPING SETS((r_reason_id,r_reason_sk),r_reason_sk); |
Example of the UNION clause: Merge the names started with W and N in the r_reason_desc column in the tpcds.reason table.
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SELECT r_reason_sk, tpcds.reason.r_reason_desc FROM tpcds.reason WHERE tpcds.reason.r_reason_desc LIKE 'W%' UNION SELECT r_reason_sk, tpcds.reason.r_reason_desc FROM tpcds.reason WHERE tpcds.reason.r_reason_desc LIKE 'N%'; |
Example of the NLS_SORT clause: Sort by Chinese Pinyin.
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SELECT * FROM tpcds.reason ORDER BY NLSSORT( r_reason_desc, 'NLS_SORT = SCHINESE_PINYIN_M'); |
Case-insensitive order:
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SELECT * FROM tpcds.reason ORDER BY NLSSORT( r_reason_desc, 'NLS_SORT = generic_m_ci'); |
Create the table tpcds.reason_p.
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CREATE TABLE tpcds.reason_p ( r_reason_sk integer, r_reason_id character(16), r_reason_desc character(100) ) PARTITION BY RANGE (r_reason_sk) ( partition P_05_BEFORE values less than (05), partition P_15 values less than (15), partition P_25 values less than (25), partition P_35 values less than (35), partition P_45_AFTER values less than (MAXVALUE) ); |
Insert data.
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INSERT INTO tpcds.reason_p values(3,'AAAAAAAABAAAAAAA','reason 1'),(10,'AAAAAAAABAAAAAAA','reason 2'),(4,'AAAAAAAABAAAAAAA','reason 3'),(10,'AAAAAAAABAAAAAAA','reason 4'),(10,'AAAAAAAABAAAAAAA','reason 5'),(20,'AAAAAAAACAAAAAAA','reason 6'),(30,'AAAAAAAACAAAAAAA','reason 7'); |
Example of the PARTITION clause: Obtain data from the P_05_BEFORE partition in the tpcds.reason_p table.
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SELECT * FROM tpcds.reason_p PARTITION (P_05_BEFORE); r_reason_sk | r_reason_id | r_reason_desc -------------+------------------+------------------------------------ 4 | AAAAAAAABAAAAAAA | reason 3 3 | AAAAAAAABAAAAAAA | reason 1 (2 rows) |
Example of the GROUP BY clause: Group records in the tpcds.reason_p table by r_reason_id, and count the number of records in each group.
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SELECT COUNT(*),r_reason_id FROM tpcds.reason_p GROUP BY r_reason_id; count | r_reason_id -------+------------------ 2 | AAAAAAAACAAAAAAA 5 | AAAAAAAABAAAAAAA (2 rows) |
Example of the GROUP BY CUBE clause: Filter data based on query conditions, and group the results.
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SELECT * FROM tpcds.reason GROUP BY CUBE (r_reason_id,r_reason_sk,r_reason_desc); |
Example of the GROUP BY GROUPING SETS clause: Filter data based on query conditions, and group the results.
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SELECT * FROM tpcds.reason GROUP BY GROUPING SETS ((r_reason_id,r_reason_sk),r_reason_desc); |
Example of the HAVING clause: Group records in the tpcds.reason_p table by r_reason_id, count the number of records in each group, and display only values whose number of r_reason_id is greater than 2.
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SELECT COUNT(*) c,r_reason_id FROM tpcds.reason_p GROUP BY r_reason_id HAVING c>2; c | r_reason_id ---+------------------ 5 | AAAAAAAABAAAAAAA (1 row) |
Example of the IN clause: Group records in the tpcds.reason_p table by r_reason_id, count the number of records in each group, and display only the numbers of records whose r_reason_id is AAAAAAAABAAAAAAA or AAAAAAAADAAAAAAA.
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SELECT COUNT(*),r_reason_id FROM tpcds.reason_p GROUP BY r_reason_id HAVING r_reason_id IN('AAAAAAAABAAAAAAA','AAAAAAAADAAAAAAA'); count | r_reason_id -------+------------------ 5 | AAAAAAAABAAAAAAA (1 row) |
Example of the INTERSECT clause: Query records whose r_reason_id is AAAAAAAABAAAAAAA and whose r_reason_sk is smaller than 5.
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SELECT * FROM tpcds.reason_p WHERE r_reason_id='AAAAAAAABAAAAAAA' INTERSECT SELECT * FROM tpcds.reason_p WHERE r_reason_sk<5; r_reason_sk | r_reason_id | r_reason_desc -------------+------------------+------------------------------------ 4 | AAAAAAAABAAAAAAA | reason 3 3 | AAAAAAAABAAAAAAA | reason 1 (2 rows) |
Example of the EXCEPT clause: Query records whose r_reason_id is AAAAAAAABAAAAAAA and whose r_reason_sk is greater than or equal to 4.
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SELECT * FROM tpcds.reason_p WHERE r_reason_id='AAAAAAAABAAAAAAA' EXCEPT SELECT * FROM tpcds.reason_p WHERE r_reason_sk<4; r_reason_sk | r_reason_id | r_reason_desc -------------+------------------+------------------------------------ 10 | AAAAAAAABAAAAAAA | reason 2 10 | AAAAAAAABAAAAAAA | reason 5 10 | AAAAAAAABAAAAAAA | reason 4 4 | AAAAAAAABAAAAAAA | reason 3 (4 rows) |
Specify the operator (+) in the WHERE clause to indicate a left join.
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select t1.sr_item_sk ,t2.c_customer_id from store_returns t1, customer t2 where t1.sr_customer_sk = t2.c_customer_sk(+) order by 1 desc limit 1; sr_item_sk | c_customer_id ------------+--------------- 18000 | (1 row) |
Specify the operator (+) in the WHERE clause to indicate a right join.
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select t1.sr_item_sk ,t2.c_customer_id from store_returns t1, customer t2 where t1.sr_customer_sk(+) = t2.c_customer_sk order by 1 desc limit 1; sr_item_sk | c_customer_id ------------+------------------ | AAAAAAAAJNGEBAAA (1 row) |
Specify the operator (+) in the WHERE clause to indicate a left join and add a join condition.
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select t1.sr_item_sk ,t2.c_customer_id from store_returns t1, customer t2 where t1.sr_customer_sk = t2.c_customer_sk(+) and t2.c_customer_sk(+) < 1 order by 1 limit 1; sr_item_sk | c_customer_id ------------+--------------- 1 | (1 row) |
If the operator (+) is specified in the WHERE clause, do not use expressions connected through AND/OR.
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select t1.sr_item_sk ,t2.c_customer_id from store_returns t1, customer t2 where not(t1.sr_customer_sk = t2.c_customer_sk(+) and t2.c_customer_sk(+) < 1); ERROR: Operator "(+)" can not be used in nesting expression. LINE 1: ...tomer_id from store_returns t1, customer t2 where not(t1.sr_... ^ |
If the operator (+) is specified in the WHERE clause which does not support expression macros, an error will be reported.
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select t1.sr_item_sk ,t2.c_customer_id from store_returns t1, customer t2 where (t1.sr_customer_sk = t2.c_customer_sk(+))::bool; ERROR: Operator "(+)" can only be used in common expression. |
If the operator (+) is specified on both sides of an expression in the WHERE clause, an error will be reported.
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select t1.sr_item_sk ,t2.c_customer_id from store_returns t1, customer t2 where t1.sr_customer_sk(+) = t2.c_customer_sk(+); ERROR: Operator "(+)" can't be specified on more than one relation in one join condition HINT: "t1", "t2"...are specified Operator "(+)" in one condition. |
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