All Documents
Relational Database ServiceRelational Database Service
- What's New
- Function Overview
- Service Overview
-
Getting Started
-
Getting Started with RDS for MySQL
- Operation Guide
- Step 1: Buy a DB Instance
- Step 2: Connect to a DB Instance
- Example: Buy and Connect to an RDS for MySQL DB Instance
-
Getting Started with RDS for PostgreSQL
- Operation Guide
- Step 1: Buy a DB Instance
- Step 2: Connect to a DB Instance
- Getting Started with RDS for SQL Server
- Change History
-
Getting Started with RDS for MySQL
- HUAWEI CLOUD MySQL Kernel
-
User Guide
-
Working with RDS for MySQL
- Instance Connection
- Usage Specifications and Suggestions
- Database Migration
-
Performance Tuning
- Suggestions on MySQL Parameter Tuning
- What Is the Maximum Number of IOPS Supported by RDS?
- How Do I Improve the Query Speed of My RDS Database?
- Identifying Why CPU Usage of RDS for MySQL DB Instances Is High and Providing Solutions
- RDS for MySQL Memory Usage Too High
- What Should I Do If an RDS DB Instance Is Abnormal Due to Full Storage Space?
- Resolving Database Operation Failures Caused by Metadata Locks on RDS for MySQL
- Troubleshooting Slow SQL Issues for RDS for MySQL DB Instances
- Permissions Management
- Instance Lifecycle
-
Instance Modifications
- Upgrading a Minor Version
- Upgrading a Major Version
- Changing a DB Instance Name
- Changing a DB Instance Description
- Changing the Replication Mode
- Changing the Failover Priority
- Changing a DB Instance Class
- Scaling up Storage Space
- Storage Autoscaling
- Changing the Maintenance Window
- Changing a DB Instance Type from Single to Primary/Standby
- Promoting a Read Replica Into a Single DB Instance
- Manually Switching Between Primary and Standby DB Instances
- Migrating a Standby DB Instance
- Read Replicas
- DR Management
-
Backups and Restorations
- Working with Backups
- Restoring a DB Instance
- Configuring an Automated Backup Policy
- Creating a Manual Backup
- Checking and Exporting Backup Information
- Downloading a Full Backup File
- Downloading a Binlog Backup File
- Setting a Local Retention Period for RDS for MySQL Binlogs
- Downloading mysqlbinlog
- Restoring from Backup Files to DB Instances
- Restoring from Backup Files to a Self-Built MySQL Database
- Restoring a DB Instance to a Point in Time
- Restoring a Table to a Point in Time
- Replicating a Backup
- Deleting a Manual Backup
-
Parameter Template Management
- Creating a Parameter Template
- Modifying Parameters
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
-
Database Proxy (Read/Write Splitting)
- Introducing Read/Write Splitting
- Suggestions on Using Database Proxy
- Database Proxy Billing
- Database Proxy Kernel Version Description
- Best Practices for Database Proxy
- Configuring Transaction Splitting
- Enabling Read/Write Splitting
- Configuring Delay Threshold and Distributing Read Weight
- Changing the Read/Write Splitting Address
- Changing the Instance Class of a DB Proxy Instance
- Changing the Number of Proxy Nodes
- Upgrading the Kernel Version of Database Proxy
- Enabling or Disabling Access Control
- Disabling Read/Write Splitting
- Rules for Distributing Weights
- Testing Read/Write Splitting Performance
- Application Lossless and Transparent (ALT)
- Database Management
- Account Management (Non-Administrator)
-
Data Security
- Database Account Security
- Resetting the Administrator Password to Restore Root Access
- Changing a Security Group
- Performing a Server-Side Encryption
- Configuring an SSL Connection
- Configuring a Password Expiration Policy
- Unbinding an EIP
- Using the Database of the Latest Version
- Using DBSS (Recommended)
- Metrics and Alarms
- Interconnection with CTS
- Log Management
- Task Center
- Billing Management
- Managing Tags
- Managing Quotas
-
Working with RDS for PostgreSQL
-
Instance Connection
- Connecting to an RDS for PostgreSQL Instance
- Connecting to an RDS for PostgreSQL Instance Through DAS (Recommended)
- Connecting to an RDS for PostgreSQL Instance Through the psql CLI Client
- Connecting to an RDS for PostgreSQL Instance Through the GUI
- Connecting to an RDS for PostgreSQL Instance Through JDBC
- Suggestions on Using RDS for PostgreSQL
- Database Migration
- Performance Tuning
- RDS for PostgreSQL Enhanced Edition
- RDS for PostgreSQL Kernel Functions
- Permissions Management
- Instance Lifecycle
-
Instance Modifications
- Changing a DB Instance Name
- Changing a DB Instance Description
- Changing the Replication Mode
- Changing the Failover Priority
- Changing a DB Instance Class
- Scaling up Storage Space
- Changing the Maintenance Window
- Changing a DB Instance Type from Single to Primary/Standby
- Manually Switching Between Primary and Standby DB Instances
- Migrating a Standby DB Instance
- Read Replicas
-
Backups and Restorations
- Working with Backups
- Restoring a DB Instance
- Configuring an Automated Backup Policy
- Creating a Manual Backup
- Checking and Exporting Backup Information
- Downloading a Full Backup File
- Downloading an Incremental Backup File
- Restoring from Backup Files to RDS for PostgreSQL
- Restoring from Full Backup Files to a Self-Built PostgreSQL Database
- Restoring from Incremental Backup Files to a Self-Built PostgreSQL Database
- Restoring a DB Instance to a Point in Time
- Replicating a Backup
- Deleting a Manual Backup
-
Parameter Template Management
- Creating a Parameter Template
- Modifying Instance Parameters
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
- Plugin Management
- Tablespace Management
- Database Account Security
- Data Security
- Metrics and Alarms
- Interconnection with CTS
- Log Management
- Task Center
- Billing Management
- Major Version Upgrade
- Managing Tags
- Managing Quotas
-
Instance Connection
-
Working with RDS for SQL Server
- Instance Connection
- Suggestions on Using RDS for SQL Server Instances
- Collations
- Database Migration
- Permissions Management
- Instance Lifecycle
-
Instance Modifications
- Changing a DB Instance Name
- Changing a DB Instance Description
- Changing the Failover Priority
- Cloning a DB Instance
- Changing a DB Instance Class
- Scaling up Storage Space
- Changing the Maintenance Window
- Changing a DB Instance Type from Single to Primary/Standby
- Manually Switching Between Primary and Standby DB Instances
- Read Replicas
-
Backups and Restorations
- Working with Backups
- Restoring a DB Instance
- Configuring an Automated Backup Policy
- Creating a Manual Backup
- Checking and Exporting Backup Information
- Downloading a Backup File
- Restoring from Backup Files to RDS for SQL Server
- Restoring from Backup Files to a Self-Built SQL Server Database
- Restoring a DB Instance to a Point in Time
- Replicating a Backup
- Deleting a Manual Backup
-
Parameter Template Management
- Creating a Parameter Template
- Modifying Parameters
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Version Upgrade
- Connection Management
- Database and Account Management (Non-Administrator)
- Database Account Security
- Data Security
- Distributed Transactions
- SQL Server Integration Services (SSIS)
- Metrics and Alarms
- Interconnection with CTS
- Log Management
- Task Center
- Billing Management
- Enabling or Disabling FileStream
- CLR Integration
- Default Language Setting for Microsoft SQL Server
-
Usage of Stored Procedures
- Creating a Database Account
- Granting SSIS Permissions to a Domain Account
- Deploying an SSIS Project
- Changing Custom Database Names
- Viewing Error Logs
- Tracing Flags
- Capturing Change Data
- Removing a Custom Database from an Availability Group
- Replicating Databases
- Granting Database Permissions to Subaccounts
- Deleting Custom Databases
- Updating Database Statistics
- Cycling SQL Server Agent Error Logs
- Cycling SQL Server Error Logs
- Creating Alerts
- Setting Up Notifications for Alert
- Creating Operators for Alerts and Jobs
- Updating Alert Settings
- Updating Alert Notification Methods
- Updating Information About Operators for Alerts and Jobs
- Removing Alerts
- Removing SQL Server Agent Notification Definitions for Specific Alerts and Operators
- Removing Operators
- Shrinking Databases
- Configuring TRUSTWORTHY for a Database
- Changing the Permission to View All Databases
- Granting Permissions of Database-Level db_owner Role
- Managing Tags
- Managing Quotas
- Change History
-
Working with RDS for MySQL
-
Best Practices
-
MySQL
- Specifications on Using RDS for MySQL
- Migrating Data from Self-built MySQL Databases to RDS for MySQL Instances
- Configuring Remote DR for a Single RDS for MySQL Instance Using DRS
- Migrating MySQL Databases from Other Clouds to Huawei Cloud RDS for MySQL
- Using RDS for MySQL to Set Up WordPress
- Using RDS for MySQL to Set Up Discuz!
- Downloading a Backup File and Restoring Data from It
- Description of innodb_flush_log_at_trx_commit and sync_binlog
- Resolving Database Operation Failures Caused by Metadata Locks on RDS for MySQL
- How Do I Use the utf8mb4 Character Set to Store Emojis in an RDS for MySQL DB Instance?
-
Performance Tuning
- Identifying Why CPU Usage of RDS for MySQL DB Instances Is High and Providing Solutions
- RDS for MySQL Performance Tuning – Resolving Insufficient Storage Issues
- RDS for MySQL Performance Tuning – Resolving High Memory Usage Issues
- RDS for MySQL Performance Tuning – Resolving High I/O Issues
- Troubleshooting Slow SQL Issues for RDS for MySQL DB Instances
- PostgreSQL
-
Microsoft SQL Server
- Restoring Data from Backup Files to RDS Microsoft SQL Server DB Instances
- Migrating Data from a Self-Built SQL Server Database on an ECS to an RDS Microsoft SQL Server DB Instance
- Modifying Parameters in a Parameter Template
- Supporting DMVs
- Using the Import and Export Function to Migrate Data from a Local Database to an RDS Microsoft SQL Server DB Instance
- Creating a Subaccount of rdsuser
- Creating tempdb Files
- Microsoft SQL Server Publication and Subscription
- Installing a C# CLR Assembly in RDS for SQL Server
- Creating a Linked Server for an RDS SQL Server DB Instance
- Deploying SQL Server Reporting Services (SSRS) on RDS for SQL Server
- Shrinking an RDS for SQL Server Database
- Using DAS to Create and Configure Agent Job and DBLink on the Master and Slave Databases for SQL Server Instances
- Creating a Job for Scheduled Instance Maintenance
-
MySQL
- Security White Paper
- Performance White Paper
-
API Reference
- Before You Start
- API Overview
- Calling APIs
-
API v3 (Recommended)
- Querying Version Information About APIs
- Querying Version Information About a DB Engine
- Querying Database Specifications
- Querying the Storage Type of a Database
-
DB Instance Management
- Creating a DB Instance
- Changing a DB Instance Name
- Changing a DB Instance Description
- Applying for a Private Domain Name
- Modifying a Private Domain Name
- Changing DB Instance Specifications
- Scaling Up Storage Space of a DB Instance
- Changing a Single DB Instance to Primary/Standby DB Instances
- Rebooting a DB Instance
- Deleting a DB Instance
- Querying Details About DB Instances
- Binding and Unbinding an EIP
- Changing the Failover Priority
- Manually Switching Primary/Standby DB Instances
- Changing the Data Replication Mode of Primary/Standby DB Instances
- Migrating a Standby DB Instance
- Configuring the Maintenance Window
- Upgrading a Minor Version
- DR Instances
- Database Security
-
Parameter Configuration
- Obtaining a Parameter Template List
- Creating a Parameter Template
- Modifying a Parameter Template
- Applying a Parameter Template
- Modifying Parameters of a Specified DB Instance
- Obtaining the Parameter Template of a Specified DB Instance
- Obtaining Parameters in a Specified Parameter Template
- Deleting a Parameter Template
-
Backup and Restoration
- Setting an Automated Backup Policy
- Setting a Cross-Region Backup Policy
- Obtaining an Automated Backup Policy
- Querying Information About a Cross-Region Backup Policy
- Creating a Manual Backup
- Obtaining Details About Backups
- Querying Details About Cross-Region Backups
- Querying Details About DB Instances for Which Cross-Region Backups Are Created
- Obtaining the Link for Downloading a Backup File
- Deleting a Manual Backup
- Querying the Restoration Time Range
- Querying the Restoration Time Range of a Cross-Region Backup
- Restoring Data to a New DB Instance
- Restoring Data to an Existing DB Instance
- Restoring Tables to a Specified Point in Time (MySQL)
-
Log Information Queries
- Querying Database Error Logs
- Querying Database Error Logs (MySQL)
- Querying Database Slow Logs (MySQL)
- Obtaining Slow Query Log Statistics
- Obtaining Links for Downloading Slow Query Logs
- Setting SQL Audit
- Querying the Policy for SQL Audit Logs
- Obtaining an Audit Log List
- Obtaining the Link for Downloading an Audit Log
- Setting the Local Retention Period of Binlogs
- Obtaining the Local Retention Period of Binlogs
-
Database and Account Management (MySQL)
- Precautions
- Creating a Database
- Querying Details About a Database (Discarded)
- Querying Details About Databases
- Querying Authorized Databases of a Specified User
- Modifying the Database Remarks of a Specified DB Instance
- Deleting a Database
- Creating a Database Account
- Querying Details About a Database User (Discarded)
- Querying Details About Database Users
- Querying Authorized Users of a Specified Database
- Deleting a Database Account
- Configuring a Password for a Database Account
- Authorizing a Database Account
- Revoking Permissions of a Database Account
- Resetting the Password for User Root
- Database and Account Management (PostgreSQL)
-
Database and Account Management (Microsoft SQL Server)
- Querying the Available SQL Server Character Set
- Creating a Database
- Querying Details About Databases
- Deleting a Database
- Creating a Database Account
- Querying Details About Database Users
- Querying Authorized Users of a Specified Database
- Deleting a Database Account
- Authorizing a Database Account
- Revoking Permissions of a Database Account
- Recycling a DB Instance
- Tag Management
- Quota Management
- Obtaining Task Information
- API v3 (Unavailable Soon)
- Permissions Policies and Supported Actions
- Appendix
- Change History
-
FAQs
-
Product Consulting
- What Should I Pay Attention to When Using RDS?
- What Is the Availability of RDS DB Instances?
- How Do I Distinguish Between General-Purpose and Dedicated RDS for MySQL Instances Using Cloud SSDs?
- Will My RDS DB Instances Be Affected by Other User Instances?
- Does RDS Support Cross-AZ High Availability?
- Can RDS Primary/Standby DB Instances Be Changed to Single DB Instances?
- How Do I Create an AD Domain?
- What Can I Do About Slow Respond of Websites When They Use RDS?
- Can I Change the Synchronize Model Between Primary DB Instances and Read Replicas?
- What Is the Time Delay for Primary/Standby Synchronization?
- Can Multiple ECSs Connect to the Same RDS DB Instance?
- Can Primary and Standby RDS DB Instances Be Deployed in the Same AZ?
- Can I Encrypt the Disk After Purchasing an RDS DB Instance?
- Does RDS for MySQL Support Encryption Functions?
- Does a Self-Built MySQL Database on an ECS Support Primary/Standby Replication?
- What Are the Restrictions on RDS for MySQL DB Instances After GTID Is Enabled?
- Will Different RDS DB Instances Share CPU and Memory Resources?
- Does RDS Support 3-AZ Deployment?
- How Many DB Instances Can Run on RDS?
- Is RDS for MySQL Compatible with MariaDB?
- Does RDS for MySQL Support TokuDB?
- What Is the Maximum Size Allowed for a Single Table in RDS for MySQL Instances?
- Resource and Disk Management
-
Database Connection
- What Should I Do If I Fail to Connect to an RDS DB Instance?
- Can an External Server Access the RDS Database?
- What Do I Do If the Number of RDS Database Connections Reaches the Upper Limit?
- What Is the Maximum Number of Connections to an RDS DB Instance?
- How Can I Create and Connect to an ECS?
- What Should I Do If an ECS Cannot Connect to an RDS DB Instance Through a Private Network?
- What Should I Do If a Database Client Problem Causes a Connection Failure?
- What Should I Do If an RDS Database Problem Causes a Connection Failure?
- How Do My Applications Access an RDS DB Instance in a VPC?
- Do Applications Need to Support Reconnecting to the RDS DB Instance Automatically?
- How Can I Connect to an RDS for MySQL Instance Through JDBC?
- How Can I Connect to an RDS for PostgreSQL Database Through JDBC?
- Why Cannot I Ping My EIP After It Is Bound to a DB Instance?
- How Can I Obtain the IP Address of an Application?
- What Should I Do If an RDS for SQL Server DB Instance Failed to Be Connected?
- What Can I Do If the Connection Test Failed?
- Can I Access an RDS DB Instance Over an Intranet Connection Across Regions?
- Is an SSL Connection to a DB Instance Interrupted After a Primary/Standby Switchover or Failover?
- Can RDS DB Instances in Different VPCs Communicate with Each Other Over an Intranet Connection?
- Is the Bandwidth Limited When an ECS Connects to an RDS DB Instance?
- Are There Any Potential Risks If There Are Too Many Connections to RDS for MySQL DB Instances?
- Does RDS for MySQL Support SSL Connections?
- Why Did the New Password Not Take Effect After I Reset the Administrator Password?
- Does RDS for SQL Server Support Periodic Password Changes?
- Will I Be Logged Out If the Connection to RDS for SQL Server Instances Times Out?
- How Do I Set the Encoding Format of the MySQL 8.0 Character Set?
- What Should I Do If the ECS and RDS Are Deployed in Different VPCs and They Cannot Communicate with Each Other?
- How Do I View All IP Addresses Connected to a Database?
- Can I Access Standby RDS DB Instances?
- How Do I Implement Fine-Grained Permission Control to Access RDS?
- What Should I Do If No EIPs Are Available When I'm Attempting to Bind an EIP?
- Database Migration
-
Database Permission
- Why Does the Root User Not Have the Super Permissions?
- How Do I Grant RDS FullAccess Permissions to a Sub-user?
- RDS System Permissions
- What Are the Differences Between RDS ManageAccess and DAS Permissions?
- RDS for MySQL Built-in Accounts
- Does RDS for MySQL Support Multiple Accounts?
- Can Multiple Users Log In to DAS at the Same Time? Will the Accounts Be Locked If I Enter Wrong Passwords Several Times in a Row?
- Why Did I Fail to Create an Object on the postgres Database as a Common User?
- What Should I Do If a Role Failed to Be Deleted from an RDS for PostgreSQL Instance?
- Why Did My RDS for PostgreSQL Migration Fail?
- How Do I Grant the REPLICATION Permission to an RDS for PostgreSQL Database User?
- Why Is An Error Reported When I Attempt to Change a Table Owner of the RDS for PostgreSQL Database?
- How Are the Login Name Permissions of RDS for SQL Server 2017 Enterprise Edition Primary/Standby DB Instances Synchronized to Its Read Replicas?
- After a Primary Instance Account Is Deleted and Recreated on RDS for SQL Server, Will the Permissions Be Automatically Synchronized?
- How Do I View Authorized Databases After a Local Client Is Connected to a DB Instance?
-
Database Storage
- What Storage Engines Does RDS for MySQL Support?
- What Types of Storage Does RDS Use?
- Does RDS for MySQL Support Stored Procedures and Functions?
- Can I Change the Storage Type of an RDS DB Instance from Common I/O to Ultra-high I/O?
- Why Did My Primary RDS DB Instance Become Read-Only?
- What Should I Do If My Data Exceeds the Available Storage of an RDS DB Instance?
- How Do I View the Storage Usage of My RDS Instance?
- Client Installation
-
Database Usage
- Does MySQL 8.0 Support Full-Text Search?
- How Do I Use DAS to Query SQL Statements?
- How Do I Use the mysqlbinlog Tool?
- How Do I View Session IDs and Login and Logout Time of a Database?
- How Do I Create a Scheduled Task?
- What Should I Do If Garbled Characters Are Displayed After SQL Query Results Are Exported to an Excel File?
- Does the OPTIMIZE TABLE Operation Lock Tables on an RDS DB Instance?
- Why Is an Error Reported When I Attempt to Delete a Database from RDS for SQL Server Primary/Standby DB Instances?
- What Do I Need to Pay Attention to About the Time Data Type of RDS for PostgreSQL Enhanced Edition?
-
Backup and Restoration
- How Long Does RDS Store Backup Data For?
- How Do I Clear RDS Backup Space?
- Can My Database Be Used in the Backup Window?
- How Is RDS Backup Data Charged?
- How Do I View My Backup Storage Usage?
- How Can I Back Up an RDS Database to an ECS?
- Will Backups Be Retained After My RDS Instance Is Deleted?
- Will the Backup Data File Be Retained After an RDS DB Instance Is Deleted?
- How Can I Retrieve Databases and Tables Deleted by Mistake?
- How Are Unsynchronized Backups Generated for RDS for SQL Server DB Instances?
- Why Has My Automated Backup Failed?
- What Happens to Database Backups After an RDS DB Instance Is Deleted?
- Why Is a Table or Data Missing from My Database?
- Does RDS for PostgreSQL Support Table PITR?
- Can I Dump Backup Files to OBS Buckets?
- Does RDS for MySQL Support Table-Level Backup to a Specified OBS Bucket?
- Does RDS for MySQL Support Binlog Reading?
- Can I Delete the RDS for MySQL Backup Policy?
- Read Replicas and Read/Write Splitting
- Database Monitoring
- Capacity Expansion and Specification Change
-
Database Parameter Modification
- What Inappropriate Parameter Settings Cause Unavailability of the RDS for PostgreSQL Database?
- How Can I Change the Time Zone?
- How Do I Configure a Password Expiration Policy for RDS for MySQL DB Instances?
- How Do I Change the RDS Transaction Isolation Level?
- How Do I Ensure that the Character Set of an RDS MySQL Database Is Correct?
- Does RDS for PostgreSQL Support the test_decoding Plugin?
- How Do I Use the utf8mb4 Character Set to Store Emojis in an RDS for MySQL DB Instance?
- Where Should I Store NDF Files for RDS for SQL Server?
- Can I Use SQL Commands to Modify Global Parameters?
- How Do I Modify the Collation of RDS for SQL Server?
- How Do I Set Case Sensitivity for RDS for MySQL Table Names?
- What Should I Do If I Do Not Have the Permission to Change the event_scheduler Settings?
-
Log Management
- How Do I View All SQL Logs Executed by RDS for MySQL?
- What's the Slow Query Threshold for RDS for SQL Server?
- How Can I Obtain RDS for SQL Server Error Logs Using Commands?
- Can I Export Statistics on RDS Slow Query Logs?
- Does the SQL Audit Function Affect Database Performance?
- How Long Can RDS Failover/Switchover Logs Be Retained?
- How Do I View Deadlock Logs of RDS for MySQL?
-
Network Security
- What Security Protection Policies Does RDS Have?
- How Can I Ensure the Security of RDS DB Instances in a VPC?
- How Can Data Security Be Ensured During Transmission When I Access RDS Through an EIP?
- How Can I Prevent Untrusted Source IP Addresses from Accessing RDS?
- How Do I Configure a Security Group to Enable Access to RDS DB Instances?
- Can I Edit or Delete the Security Group Associated with an RDS DB Instance?
- How Can I Import the Root Certificate to a Windows or Linux OS?
- How Can I Identify the Validity Period of an SSL Root Certificate?
- How Can I Identify Data Corruption?
- Version Upgrade
- Developer-Related APIs and SDKs
- Change History
-
Product Consulting
-
Troubleshooting
- Why Is My SQL Query Running So Slow?
- Viewing Storage of RDS DB Instances
- Abnormal Replication Between Primary and Standby RDS DB Instances
- RDS for MySQL DB Instance Inaccessible
- Tables Failed to Be Found After Case-Sensitivity Setting Changes for RDS for MySQL
- Precautions for Exporting Large Tables Through mysqldump
- RDS for MySQL Client Automatically Disconnected from a DB Instance
- Commands for Exporting Data Through mysqldump
- SQL Statements Such as SET @@SESSION.SQL_LOG_BIN Displayed After You Run mysqldump
- RENAME USER Execution Failure
- Solution to the Failure of Converting the Field Type
- Account Creation Failure for a Microsoft SQL Server Database Migrated from Alibaba Cloud to Huawei Cloud
- Failed to Bind a New User to an RDS for SQL Server DB Instance That Was Recovered from Backup
- Failed to Change the Instance Class of an RDS for SQL Server Instance or Perform a Primary/Standby Switchover
- How Do I Remove and Re-establish a Replication of My RDS for SQL Server Instance?
- System Inaccessible After Field Addition to an RDS for MySQL Database Table
- RDS Point-in-Time Restoration Task Failure
- Native Error 1461 Reported by an RDS for MySQL DB Instance
- ERROR [1412] Reported by an RDS for MySQL DB Instance
- [ERROR] 1071 Reported When an Index Fails to Be Created for RDS for MySQL
- "Row size too large" Reported When an RDS for MySQL Table Failed to Be Created
- ERROR[1451] Reported When a Table with Foreign Keys Cannot Be Deleted
- MySQL-server Connection Failure After a Version Upgrade of RDS for MySQL
- Database Connection Through Code (php/java/python) Failed After SSL Is Enabled
- Automated Incremental Backup Failed Due to Full Storage
- Incorrect Login Password During Data Restoration from a Local Backup File
- Login Failed After the authentication_string Field Is Changed to Display the Password for RDS for MySQL
- RDS for MySQL Backup Job Failure
- Restoring an On-Premises or HUAWEI CLOUD Backup File to an RDS DB Instance
- Change History
- Video
- Glossary
-
More Documents
-
User Guide (ME-Abu Dhabi Region)
- Introduction
- Getting Started with RDS for MySQL
- Getting Started with RDS for PostgreSQL
- Getting Started with RDS for SQL Server
-
Working with RDS for MySQL
- Data Migration
- Instance Management
- Instance Modifications
- Read Replicas
-
Backups and Restorations
- Working with Backups
- Configuring an Automated Backup Policy
- Creating a Manual Backup
- Downloading a Backup File
- Downloading a Binlog Backup File
- Setting a Local Retention Period for MySQL Binlogs
- Restoring from Backup Files to RDS for MySQL
- Restoring from Backup Files to a Self-Built MySQL Database
- Restoring a DB Instance to a Point in Time
- Restoring a Table to a Specified Point in Time
- Replicating a Backup
- Deleting a Manual Backup
-
Parameter Template Management
- Suggestions on Tuning MySQL Parameters
- Creating a Parameter Template
- Modifying Parameters
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
- Database Management
- Account Management (Non-Administrator)
- Database Account Security
- Data Security
- Metrics
- Log Management
- Task Center
- Managing Tags
-
Working with RDS for PostgreSQL
- Data Migration
- PostgreSQL Enhanced Edition
- Instance Management
- Instance Modifications
- Read Replicas
- Backups and Restorations
-
Parameter Template Management
- Creating a Parameter Template
- Modifying Parameters
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
- Database Account Security
- Data Security
- Metrics
- Log Management
- Task Center
- Plugin Management
- Managing Tags
-
Working with RDS for SQL Server
- Instance Management
- Instance Modifications
- Read Replicas
- Backups and Restorations
-
Parameter Template Management
- Creating a Parameter Template
- Modifying Parameters
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
- Data Security
- Metrics
- Log Management
- Task Center
- Usage of Stored Procedures
- Managing Tags
-
FAQs
-
Product Consulting
- What Precautions Should Be Taken When Using RDS?
- What Is the Availability of RDS DB Instances?
- Can I Use a Template to Create DB Instances?
- What Are the Differences Between RDS and Other Database Solutions?
- Will My RDS DB Instances Be Affected by Other Users' DB Instances?
- Does RDS Support Cross-AZ High Availability?
- Can RDS Primary/Standby DB Instances Be Changed to Single DB Instances?
- What Should I Do If Garbled Characters Are Displayed After SQL Query Results Are Exported to an Excel File?
- What Can I Do About Websites Responding Slower After Using RDS?
- How Does a Cloud Database Perform a Primary/Standby Switchover?
- Can Multiple ECSs Connect to the Same RDS DB Instance?
- Why an Error is Reported When I Attempt to Delete a Database from RDS SQL Server Primary/Standby DB Instances?
- Can Primary and Standby RDS DB Instances Be Deployed in the Same AZ?
-
Resource and Disk Management
- Which Types of Logs and Files Occupy RDS Storage Space?
- Which Items Occupy the Storage Space of My RDS DB Instances?
- What Overhead Does the Storage Space Have After I Applied for an RDS DB Instance?
- How Much Storage Space Is Required for DDL Operations?
- How Many DB Instances Can Run on RDS?
- How Many Databases Can Run on an RDS DB Instance?
-
Database Connection
- Can an External Server Access the RDS Database?
- How Do I Troubleshoot If the Number of RDS Database Connections Reaches the Upper Limit?
- What Is the Maximum Number of Connections to an RDS DB Instance?
- How Can I Create and Connect to an ECS?
- What Should I Do If an ECS Cannot Connect to an RDS DB Instance?
- What Should I Do If a Database Client Problem Causes a Connection Failure?
- What Should I Do If an RDS Database Problem Causes a Connection Failure?
- How Do My Applications Access an RDS DB Instance in a VPC?
- Do Applications Need to Support Reconnecting to the RDS DB Instance Automatically?
- How Can I Connect to a PostgreSQL Database Through JDBC?
- What Should I Do If an RDS Microsoft SQL Server DB Instance Failed to Be Connected?
- Can I Access an RDS DB Instance Over an Intranet Across Regions?
- Is an SSL Connection to a DB Instance Interrupted After a Primary/Standby Switchover or Failover Occurs?
- Does MySQL Support SSL Connections?
- Why Does the New Password Not Take Effect After I Reset the Administrator Password?
- Database Migration
- Database Permission
- Database Storage
- Client Installation
-
Backup and Restoration
- How Long Does RDS Store Backup Data?
- Can My Database Be Used in the Backup Window?
- How Can I Back Up RDS Databases to an ECS?
- Why Has My Automated Backup Failed?
- What Happens to Database Backups After an RDS DB Instance Is Deleted?
- Will My Backups Be Deleted If I Delete My Cloud Account?
- Why Is a Table or Data Missing from My Database?
- Database Monitoring
- Capacity Expansion and Specification Change
- Database Parameter Modification
- Log Management
-
Network Security
- What Security Protection Policies Does RDS Have?
- How Can I Ensure the Security of RDS DB Instances in a VPC?
- How Can Data Security Be Ensured During Transmission When I Access RDS Through an EIP?
- How Can I Prevent Untrusted Source IP Addresses from Accessing RDS?
- How Can I Import the Root Certificate to the Windows or Linux OS?
- How Can I Identify Data Corruption?
-
Product Consulting
-
API Reference (ME-Abu Dhabi Region)
- Before You Start
- API Overview
- Calling APIs
- Obtaining an API Version
-
API v3 (Recommended)
- Querying Version Information About a DB Engine
- Querying Database Specifications
- Querying the Storage Type of a Database
-
DB Instance Management
- Creating a DB Instance
- Changing DB Instance Specifications
- Scaling Up Storage Space of a DB Instance
- Changing a Single DB Instance to Primary/Standby DB Instances
- Rebooting a DB Instance
- Querying the Available SQL Server Character Set
- Deleting a DB Instance
- Querying Details About DB Instances
- Binding and Unbinding an EIP
- Resetting a Database Password
- Changing the Failover Priority
- Manually Switching Primary/Standby DB Instances
- Changing the Data Synchronize Model of Primary/Standby DB Instances
- Migrating a Standby DB Instance
- Configuring the Maintenance Window
- Database Security
-
Parameter Configuration
- Obtaining a Parameter Template List
- Creating a Parameter Template
- Modifying a Parameter Template
- Applying a Parameter Template
- Modifying Parameters of a Specified DB Instance
- Obtaining the Parameter Template of a Specified DB Instance
- Obtaining Parameters in a Specified Parameter Template
- Deleting a Parameter Template
-
Backup and Restoration
- Setting an Automated Backup Policy
- Obtaining an Automated Backup Policy
- Creating a Manual Backup
- Obtaining Details About Backups
- Obtaining the Link for Downloading a Backup File
- Deleting a Manual Backup
- Querying the Restoration Time Range
- Restoring Data to a New DB Instance
- Restoring Data to an Existing DB Instance
- Restoring Tables to a Specified Point in Time (MySQL)
- Log Information Queries
-
Database and Account Management (MySQL)
- Precautions
- Creating a Database
- Querying Details About Databases
- Querying Authorized Databases of a Specified User
- Deleting a Database
- Creating a Database Account
- Querying Details About Database Users
- Querying Authorized Users of a Specified Database
- Deleting a Database Account
- Configuring a Password for a Database Account
- Authorizing a Database Account
- Revoking Permissions of a Database Account
- Database and Account Management (Microsoft SQL Server)
- Appendix
-
User Guide (Paris and Amsterdam Regions)
- Introduction
- Getting Started with RDS for MySQL
- Getting Started with RDS for PostgreSQL
-
Working with RDS for MySQL
-
Instance Management
- Changing a DB Instance Name
- Changing the Failover Priority
- Changing a DB Instance Class
- Scaling Up Storage Space
- Rebooting a DB Instance
- Changing a DB Instance Type from Single to Primary/Standby
- Manually Switching Between Primary and Standby DB Instances
- Selecting Displayed Items
- Exporting DB Instance Information
- Creating a Same DB Instance
- Deleting a DB Instance or Read Replica
- Read Replicas
-
Backups and Restorations
- Working with Backups
- Configuring an Automated Backup Policy
- Creating a Manual Backup
- Downloading a Backup File
- Downloading a Binlog Backup File
- Restoring a DB Instance from a Backup
- Restoring a DB Instance to a Point in Time
- Restoring Data from MySQL Backup Files
- Replicating a Backup
- Deleting a Manual Backup
-
Parameter Template Management
- Suggestions on Tuning MySQL Parameters
- Creating a Parameter Template
- Modifying Parameters
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
- Data Migration
- Data Security
- Metrics and Alarms
- Log Management
- Task Center
-
Instance Management
-
Working with RDS for PostgreSQL
-
Instance Management
- Changing a DB Instance Name
- Changing the Failover Priority
- Changing a DB Instance Class
- Scaling Up Storage Space
- Rebooting a DB Instance
- Changing a DB Instance Type from Single to Primary/Standby
- Manually Switching Between Primary and Standby DB Instances
- Selecting Displayed Items
- Exporting DB Instance Information
- Creating a Same DB Instance
- Deleting a DB Instance or Read Replica
- Read Replicas
- Backups and Restorations
-
Parameter Template Management
- Creating a Parameter Template
- Modifying Parameters
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
- Data Migration
- Data Security
- Metrics and Alarms
- Log Management
- Task Center
- Plugin Management
-
Instance Management
-
FAQs
-
Product Consulting
- What Precautions Should Be Taken When Using RDS?
- What Is the Availability of RDS DB Instances?
- Can I Use a Template to Create DB Instances?
- What Are the Differences Between RDS and Other Database Solutions?
- Will My RDS DB Instances Be Affected by Other Users' DB Instances?
- Does RDS Support Cross-AZ High Availability?
- Can RDS Primary/Standby DB Instances Be Changed to Single DB Instances?
- What Should I Do If Garbled Characters Are Displayed After SQL Query Results Are Exported to an Excel File?
- How Do I Create an AD Domain?
- What Can I Do About Websites Responding Slower After Using RDS?
- How Does a Cloud Database Perform a Primary/Standby Switchover?
- Can Multiple ECSs Connect to the Same RDS DB Instance?
- Can Primary and Standby RDS DB Instances Be Deployed in the Same AZ?
-
Resource and Disk Management
- Which Types of Logs and Files Occupy RDS Storage Space?
- Which Items Occupy the Storage Space of My RDS DB Instances?
- What Overhead Does the Storage Space Have After I Applied for an RDS DB Instance?
- How Much Storage Space Is Required for DDL Operations?
- How Many DB Instances Can Run on RDS?
- How Many Databases Can Run on an RDS DB Instance?
-
Database Connection
- Can an External Server Access the RDS Database?
- How Do I Troubleshoot If the Number of RDS Database Connections Reaches the Upper Limit?
- What Is the Maximum Number of Connections to an RDS DB Instance?
- How Can I Create and Connect to an ECS?
- What Should I Do If an ECS Cannot Connect to an RDS DB Instance?
- What Should I Do If a Database Client Problem Causes a Connection Failure?
- What Should I Do If an RDS Database Problem Causes a Connection Failure?
- How Do My Applications Access an RDS DB Instance in a VPC?
- Do Applications Need to Support Reconnecting to the RDS DB Instance Automatically?
- How Can I Connect to a PostgreSQL Database Through JDBC?
- Can I Access an RDS DB Instance Over an Intranet Across Regions?
- Is an SSL Connection to a DB Instance Interrupted After a Primary/Standby Switchover or Failover Occurs?
- Does MySQL Support SSL Connections?
- Why Does the New Password Not Take Effect After I Reset the Administrator Password?
- Database Migration
- Database Permission
- Database Storage
- Client Installation
-
Backup and Restoration
- How Long Does RDS Store Backup Data?
- Can My Database Be Used in the Backup Window?
- How Can I Back Up RDS Databases to an ECS?
- Why Has My Automated Backup Failed?
- What Happens to Database Backups After an RDS DB Instance Is Deleted?
- Will My Backups Be Deleted If I Delete My Cloud Account?
- Why Is a Table or Data Missing from My Database?
- Database Monitoring
- Capacity Expansion and Specification Change
- Database Parameter Modification
- Log Management
-
Network Security
- What Security Protection Policies Does RDS Have?
- How Can I Ensure the Security of RDS DB Instances in a VPC?
- How Can Data Security Be Ensured During Transmission When I Access RDS Through an EIP?
- How Can I Prevent Untrusted Source IP Addresses from Accessing RDS?
- How Can I Import the Root Certificate to the Windows or Linux OS?
- How Can I Identify the Validity Period of an SSL Root Certificate?
- How Can I Identify Data Corruption?
-
Product Consulting
-
API Reference (Paris and Amsterdam Regions)
- Before You Start
- API Overview
- Calling APIs
- Obtaining an API Version
-
API v3 (Recommended)
- Querying Version Information About a DB Engine
- Querying Database Specifications
- DB Instance Management
-
Parameter Configuration
- Obtaining a Parameter Template List
- Creating a Parameter Template
- Modifying a Parameter Template
- Applying a Parameter Template
- Modifying Parameters of a Specified DB Instance
- Obtaining the Parameter Template of a Specified DB Instance
- Obtaining Parameters in a Specified Parameter Template
- Deleting a Parameter Template
-
Backup and Restoration
- Setting an Automated Backup Policy
- Obtaining an Automated Backup Policy
- Creating a Manual Backup
- Obtaining Details About Backups
- Obtaining the Link for Downloading a Backup File
- Deleting a Manual Backup
- Querying the Restoration Time Range
- Restoring Data to a New DB Instance
- Restoring Data to an Existing or Original DB Instance
- Log Information Queries
- Tag Management
- Obtaining Task Information
- Appendix
-
User Guide (ME-Abu Dhabi Region)
Functions
This section describes the built-in functions and advanced function packages added to RDS for PostgreSQL Enhanced Edition on the basis of PostgreSQL 11 open-source edition.
Built-in Function |
Description |
---|---|
add_months(date,integer) |
Returns the date plus integer months. The return type is DATE. |
appendchildxml(XMLType_instance, XPath_string, value_expr[, namespace_string]) |
Appends the value_expr node onto XPath_string specified by XMLType_instance. The namespace_string provides namespace information for the XPath_string. |
asciistr(string) |
Returns an ASCII version of the string in the database character set. Non-ASCII characters are not supported. |
bin_to_num(expr_list) |
Converts a binary string in expr_list to its equivalent decimal number. The return type is NUMBER. |
bitand(number1,number2) |
Returns the bitwise 'AND' for two supplied integers number1 and number2. The return type is BIT. |
convert(char, dest_char_set[, source_char_set]) |
Converts char in the source_char_set to the dest_char_set encoding format. This function takes effect only on the server. |
cosh(n) |
Returns the hyperbolic cosine of argument n. |
decode(expr,search1, result1[[,search2, result2],......][, default]) |
Compares expr to each search value (search1, search2, etc). If expr is equal to a search, then Oracle Database returns the corresponding result. If no match is found, then Oracle returns default. If default is omitted, then Oracle returns null. |
empty_blob() |
Returns an empty BLOB. |
hextoraw(char) |
Converts a hexadecimal string to a raw value. |
instrb(string, substring[, position[, occurrence]]) |
Searches a string for a substring using characters and return the position in the string that is the first character of a specified occurrence of the substring. The functions vary in how they determine the position of the substring to return. |
last_day(date) |
Returns the date of the last day of the month that contains date. |
lengthb(char) |
Returns the length of char. Char can be any of the data types (CHAR, VARCHAR2, NCHAR, or NVARCHAR2), or types (such as integer) that can be implicitly converted into character strings. |
listagg(measure_expr[, 'delimiter']) within group(order_by_clause) [over query_partition_clause] |
Sorts the values of the column expression measure_expr in the query_partition_clause group based on the order_by_clause rule and aggregates them into one row. Values are separated by delimiter. |
lnnvl(condition) |
Returns a value of condition expression. The return type is BOOLEAN. |
mod(n2, n1) |
Returns the remainder of n2 divided by n1. Returns n2 if n1 is 0. |
months_between(date1, date2) |
Returns the number of months between dates date1 and date2. If date1 is earlier than date2, then the result is negative. |
nanvl(n2, n1) |
Returns n1 if the single- or double-precision floating point number input value n2 is NAN. If the input value n2 is not NAN, n2 is returned. |
nchr(number) |
Returns the character having the binary equivalent to number in the national character set. |
new_time(date, timezone1, timezone2) |
Returns the date and time in time zone timezone2 when date and time in time zone timezone1 are date. The return type is DATE. |
next_day(date, char) |
Returns the date of the first weekday named by char that is later than the date (including workdays, weekends, and holidays). The return type is DATE. |
numtodsinterval(n, interval_unit) |
Converts n to an INTERVAL DAY TO SECOND literal. The value for interval_unit specifies the unit of n and must resolve to 'DAY', 'HOUR', 'MINUTE', and 'SECOND'. |
numtoyminterval(n, 'interval_unit') |
Converts n to an INTERVAL YEAR TO MONTH literal. The value for interval_unit can be YEAR or MONTH. |
nlssort(char[, nlsparam]) |
Sorts the char string according to the sorting character set specified by nlsparam. By default, char is used for sorting. |
nls_upper(char[, nlsparam]) |
Converts all alphabetic characters in the character string char to uppercase letters based on the sort sequence specified by nlsparam. The character string type is CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB, and nlsparam is in the form of NLS_SORT = sort. |
nls_lower(char[, nlsparam]) |
Converts all alphabetic characters in the character string char to lowercase letters based on the sort sequence specified by nlsparam. The character string type is CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB, and nlsparam is in the form of NLS_SORT = sort. |
nvl(expr1, expr2) |
Returns the first non-null value in expr1 and expr2. |
rawtohex(raw) |
Converts raw to a character value containing its hexadecimal representation. |
regexp_count(source_char, pattern, position, match_param) |
Returns the number of times a pattern occurs in a source string starting from the position that indicates the source_char character where the database begins the search. The match_param parameter is a text literal that lets you change the default matching behavior of the function. For example, match_param='i' specifies case-insensitive matching. |
regexp_instr(source_char, pattern[, position[, occurrence[, return_opt[, match_param[, subexpr]]]]]) |
Extends the INSTR function and allows regular expression matching. The return type is INTEGER.
|
regexp_like(source_char, pattern[,match_param]) |
source_char is a character expression. Pattern is the regular expression. The match_param parameter is a text literal that lets you change the default matching behavior of the function. |
regexp_substr(source_char, pattern[,position[,occurrence[,match_param[,subexpr]]]]) |
Matches the character string in the source_char string based on the regular expression.
|
raise_application_error(errnum, errmsg) |
Sends the error code errnum and error message errmsg to the client. |
remainder(n2, n1) |
Returns the remainder of n2 divided by n1. The remainder function is similar to mod except that mod uses floor in its formula, whereas reminder uses ROUND. The return type is NUMERIC or double-precision floating-point number (determined by the input parameter type). |
round(n,precision) |
Returns n rounded to integer places to the right of the decimal point. The precision is the number of digits in a number. |
scn_to_timestamp(number) |
Returns the approximate timestamp associated with a system change number (SCN). |
sinh(n) |
Returns the hyperbolic sine of n. If n is BINARY_FLOAT, the return type is BINARY_DOUBLE. Otherwise, the return type is NUMERIC. |
substr(char,position[,substring_length]) |
Returns a portion of string, beginning at a specified position in the string. The functions vary in how they calculate the length of the substring to return. If substring_length is not specified, the function returns all characters to the end of string. |
substrb(char, position[, substring_length]) |
Returns a portion of char, beginning at a specified position in the string. The functions vary in how they calculate the length of the substring to return. If substring_length is not specified, the function returns all characters to the end of string. |
sys_context(namespace, parameter) |
Returns the value of parameter associated with the context namespace. The return type is VARCHAR2. |
sys_guid() |
Returns a globally unique identifier (RAW value). |
sys_connect_by_path(column, char) |
Is valid only in CONNECT BY queries and returns the path of a column value from root to node. |
tanh(n) |
Returns the hyperbolic tangent of argument n. |
to_blob(char) |
Converts char strings to BLOB values. Char can be any of the data types (CHAR, VARCHAR2, NCHAR, or NVARCHAR2), or types (such as integer) that can be implicitly converted into character strings. |
to_binary_float(expr) |
Converts expr to the single-precision float type. |
to_binary_double(expr) |
Converts expr to the double-precision float type. |
to_clob(char) |
Converts char to the CLOB data type. |
to_char(char) |
Supports char types: char, character, and varchar. |
to_date(char[,fmt]) |
Converts char of the CHAR, VARCHAR2, NCHAR, NVARCHAR2, or TIMESTAMP data type to a value of the DATE data type according to the fmt format. If fmt is omitted, char must use the default format of the DATE data type. |
to_dsinterval('sql_format' | 'ds_iso_format') |
Converts the time character string of the SQL standard (such as '100 00:00:00') or ISO standard (such as 'P100DT05H') to the INTERVAL DAY TO SECOND data type. |
to_multi_byte(char) |
Converts a single-byte character char into a multi-byte character. |
to_number(expr) |
Converts expr to a value of NUMBER data type. |
to_number(expr, fmt, 'nlsparam') |
Converts expr to a value of NUMBER data type in the format specified by fmt. The nlsparam is an international language parameter and supports the following parameters: NLS_NUMERIC_CHARACTERS, NLS_CURRENCY, and NLS_ISO_CURRENCY. |
to_timestamp(char[,fmt]) |
Converts char of the CHAR, VARCHAR2, NCHAR, NVARCHAR2, or TIMESTAMP data type to a value of the timestamp data type according to the fmt format. If fmt is omitted, char must use the default format of the TIMESTAMP data type. |
to_single_byte(char) |
Converts multibyte characters to their corresponding single-byte characters. |
to_yminterval('sql_format' | 'ym_iso_format') |
Converts the time character string of the SQL standard (such as '01-02') or ISO standard (such as 'P1Y2M') to the INTERVAL MONTH TO YEAR data type. |
timestamp_to_scn(timestamp) |
Returns the approximate system change number (SCN) associated with a timestamp. |
trunc(date[, fmt]) |
Truncates date according to the date format specified by fmt. The return type is DATE. If fmt is omitted, the default date format is 'DDD'. |
tz_offset({time_zone_name | '{+|-}hh:mi'}) |
Returns the specified time zone offset. The return type is VARCHAR2. The parameter is a character string in the time_zone_name or '{+|-}hh:mi' format. |
value(correlation_variable) |
Returns the recorded row associated with correlation_variable in object table mode. The return type is the object table associated with correlation_variable. |
Advanced Function Package |
Description |
---|---|
DBMS_OUTPUT.PUT(item) |
Places the item string in the local buffer. Item indicates all types that can be converted into character strings. |
DBMS_OUTPUT.PUT_LINE(item) |
Places the item string in the local buffer and outputs all the content in the local buffer. Item indicates all types that can be converted into character strings. |
DBMS_RANDOM.SEED(val) |
Val is the seed number used to generate a random number. It can be a character string or a digit. |
DBMS_RANDOM.VALUE([low,high]) |
Returns a 16-digit random number between low and high. If the range of low and high is not specified, the default value range is 0-1. |
dbms_lob.getlength(lob_loc {clob|blob}) |
Returns the LOB length specified by lob_loc. |
dbms_lob.read(lob_loc, amount, offset, buffer) |
Returns the specified amount into the buffer parameter, starting from an absolute offset from the beginning of the LOB. |
dbms_lob.write(lob_loc, amount, offset, buffer) |
Writes the buffer content to the large object lob_loc buffer (the referenced large object is not affected) starting at offset. The amount represents the size. |
utl_raw.cast_to_raw(char) |
Converts char of the VARCHAR2 data type to RAW. The return type is RAW. |
utl_raw.length(raw) |
Returns the length of the raw data type. The return type is NUMBER. |
utl_raw.cast_from_binary_integer(n, endianess) |
Converts the integer n to the RAW type based on the memory alignment mode specified by endianess. The values of endianess are as follows:
|