Compute
Elastic Cloud Server
Huawei Cloud Flexus
Bare Metal Server
Auto Scaling
Image Management Service
Dedicated Host
FunctionGraph
Cloud Phone Host
Huawei Cloud EulerOS
Networking
Virtual Private Cloud
Elastic IP
Elastic Load Balance
NAT Gateway
Direct Connect
Virtual Private Network
VPC Endpoint
Cloud Connect
Enterprise Router
Enterprise Switch
Global Accelerator
Management & Governance
Cloud Eye
Identity and Access Management
Cloud Trace Service
Resource Formation Service
Tag Management Service
Log Tank Service
Config
OneAccess
Resource Access Manager
Simple Message Notification
Application Performance Management
Application Operations Management
Organizations
Optimization Advisor
IAM Identity Center
Cloud Operations Center
Resource Governance Center
Migration
Server Migration Service
Object Storage Migration Service
Cloud Data Migration
Migration Center
Cloud Ecosystem
KooGallery
Partner Center
User Support
My Account
Billing Center
Cost Center
Resource Center
Enterprise Management
Service Tickets
HUAWEI CLOUD (International) FAQs
ICP Filing
Support Plans
My Credentials
Customer Operation Capabilities
Partner Support Plans
Professional Services
Analytics
MapReduce Service
Data Lake Insight
CloudTable Service
Cloud Search Service
Data Lake Visualization
Data Ingestion Service
GaussDB(DWS)
DataArts Studio
Data Lake Factory
DataArts Lake Formation
IoT
IoT Device Access
Others
Product Pricing Details
System Permissions
Console Quick Start
Common FAQs
Instructions for Associating with a HUAWEI CLOUD Partner
Message Center
Security & Compliance
Security Technologies and Applications
Web Application Firewall
Host Security Service
Cloud Firewall
SecMaster
Anti-DDoS Service
Data Encryption Workshop
Database Security Service
Cloud Bastion Host
Data Security Center
Cloud Certificate Manager
Edge Security
Managed Threat Detection
Blockchain
Blockchain Service
Web3 Node Engine Service
Media Services
Media Processing Center
Video On Demand
Live
SparkRTC
MetaStudio
Storage
Object Storage Service
Elastic Volume Service
Cloud Backup and Recovery
Storage Disaster Recovery Service
Scalable File Service Turbo
Scalable File Service
Volume Backup Service
Cloud Server Backup Service
Data Express Service
Dedicated Distributed Storage Service
Containers
Cloud Container Engine
SoftWare Repository for Container
Application Service Mesh
Ubiquitous Cloud Native Service
Cloud Container Instance
Databases
Relational Database Service
Document Database Service
Data Admin Service
Data Replication Service
GeminiDB
GaussDB
Distributed Database Middleware
Database and Application Migration UGO
TaurusDB
Middleware
Distributed Cache Service
API Gateway
Distributed Message Service for Kafka
Distributed Message Service for RabbitMQ
Distributed Message Service for RocketMQ
Cloud Service Engine
Multi-Site High Availability Service
EventGrid
Dedicated Cloud
Dedicated Computing Cluster
Business Applications
Workspace
ROMA Connect
Message & SMS
Domain Name Service
Edge Data Center Management
Meeting
AI
Face Recognition Service
Graph Engine Service
Content Moderation
Image Recognition
Optical Character Recognition
ModelArts
ImageSearch
Conversational Bot Service
Speech Interaction Service
Huawei HiLens
Video Intelligent Analysis Service
Developer Tools
SDK Developer Guide
API Request Signing Guide
Terraform
Koo Command Line Interface
Content Delivery & Edge Computing
Content Delivery Network
Intelligent EdgeFabric
CloudPond
Intelligent EdgeCloud
Solutions
SAP Cloud
High Performance Computing
Developer Services
ServiceStage
CodeArts
CodeArts PerfTest
CodeArts Req
CodeArts Pipeline
CodeArts Build
CodeArts Deploy
CodeArts Artifact
CodeArts TestPlan
CodeArts Check
CodeArts Repo
Cloud Application Engine
MacroVerse aPaaS
KooMessage
KooPhone
KooDrive

Query and Index Statistics Collector

Updated on 2024-06-03 GMT+08:00

The query and index statistics collector is used to collect statistics during database running. The statistics include the times of inserting and updating a table and index, the number of disk blocks and tuples, and the time required for the last cleanup and analysis on each table. The statistics can be viewed by querying system views pg_stats and pg_statistic. The following parameters are used to set the statistics collection feature in the server scope:

track_activities

Parameter description: Collects statistics about the commands that are being executed in each session. For a stored procedure, if this parameter is enabled, you can view the PERFORM statement, stored procedure calling statement, SQL statement, and OPEN CURSOR statement that are being executed in the stored procedure in the pg_stat_activity view.

This is a SUSET parameter. Set it based on instructions provided in Table 1.

Value range: Boolean

  • on indicates that the statistics collection function is enabled.
  • off indicates that the statistics collection function is disabled.

Default value: on

CAUTION:

If this parameter is set to off, the memory recycling capability of the storage engine is affected, causing space expansion.

track_counts

Parameter description: Collects statistics about database activities.

This is a SUSET parameter. Set it based on instructions provided in Table 1.

Value range: Boolean

  • on indicates that the statistics collection function is enabled.
  • off indicates that the statistics collection function is disabled.
NOTE:

Database statistics are required when the autovacuum process checks for databases that need to be vacuumed. Therefore, the default value is set to on.

Default value: on

CAUTION:

If this parameter is set to off, the memory recycling capability of the storage engine is affected, causing space expansion.

track_procedure_sql

Parameter description: Specifies whether the SQL statements that are being executed in the stored procedure are printed in the query column in the pg_stat_activity system catalog.

Parameter type: Boolean

Unit: none

Value range: on or off

  • on: indicates that when a stored procedure is called, the statements that are being executed by the stored procedure are printed in the query column of pg_stat_activity.
  • off: indicates that when a stored procedure is called, only statements for invoking the stored procedure are printed in the query column of pg_stat_activity.

Default value: on

Setting method: This is a USERSET parameter. Set it based on instructions provided in Table 1.

Setting suggestion: none

track_io_timing

Parameter description: Collects statistics about I/O timing in the database. The I/O timing statistics can be queried by using the pg_stat_database parameter.

This is a SUSET parameter. Set it based on instructions provided in Table 1.

Value range: Boolean

  • If this parameter is set to on, the collection function is enabled. In this case, the collector repeatedly queries the OS at the current time. As a result, large number of costs may occur on some platforms. Therefore, the default value is set to off.
  • off indicates that the statistics collection function is disabled.

Default value: off

track_functions

Parameter description: Collects statistics of the number and duration of function invocations.

This is a SUSET parameter. Set it based on instructions provided in Table 1.

NOTICE:

When the SQL functions are set to inline functions queried by the invoking, these SQL functions cannot be traced no matter these functions are set or not.

Value range: enumerated values

  • pl indicates that only procedural language functions are traced.
  • all indicates that SQL language functions area traced.
  • none indicates that the function tracing function is disabled.

Default value: none

track_activity_query_size

Parameter description: Specifies byte counts of the current running commands used to trace each active session. If the actual number of bytes in a command is greater than the value of this parameter, the command is truncated.

Parameter type: integer

Unit: byte

Value range: 100 to 102400

Default value: 1024

Setting method: This is a POSTMASTER parameter. Set it based on instructions provided in Table 1.

Setting suggestion: Set this parameter based on the actual service scenario.

update_process_title

Parameter description: Collects statistics updated with a process name each time the server receives a new SQL statement.

The process name can be viewed by running the ps command.

This is an INTERNAL parameter. Set it based on instructions provided in Table 1.

Value range: Boolean

  • on indicates that the statistics collection function is enabled.
  • off indicates that the statistics collection function is disabled.

Default value: off

stats_temp_directory

Parameter description: Specifies the directory for storing temporary statistics. Only the sysadmin user can access this parameter.

This is a SIGHUP parameter. Set it based on instructions provided in Table 1.

NOTICE:

If a RAM-based file system directory is used, the actual I/O cost can be lowered and the performance can be improved.

Value range: a string

Default value: pg_stat_tmp

track_thread_wait_status_interval

Parameter description: Specifies the interval of collecting the thread status information.

This is a SUSET parameter. Set it based on instructions provided in Table 1.

Value range: 0 to 1 day. The unit is min.

Default value: 30min

enable_save_datachanged_timestamp

Parameter description: Specifies whether to record the time when INSERT, UPDATE, DELETE, or EXCHANGE/TRUNCATE/DROP PARTITION is performed on table data.

This is a USERSET parameter. Set it based on instructions provided in Table 1.

Value range: Boolean

  • on indicates that the time when an operation is performed on table data will be recorded.
  • off indicates that the time when an operation is performed on table data will not be recorded.

Default value: on

enable_plan_trace

Parameter description: Specifies whether to enable the PLAN TRACE feature for the database. This parameter cannot be set globally by running the gs_guc command. It can be set only by running the set command in a connected session.

This is a USERSET parameter. Set it based on instructions provided in Table 1.

Value range: Boolean

  • on indicates that the PLAN TRACE feature is enabled.
  • off indicates that the PLAN TRACE feature is disabled.

Default value: off

plan_collect_thresh

Parameter description: Collects statistics about the plans that are being executed in each session.

This is a SUSET parameter. Set it based on instructions provided in Table 1.

Value range: an integer ranging from –1 to 2147483647

  • –1: Plans that are being executed are not collected.
  • 0: Plans that are being executed are collected before plan execution.
  • A value greater than 0 indicates that when the total number of tuples incrementally returned by all operators in a plan is greater than or equal to the value of this parameter, plans that are being executed are collected once.

Default value: 0

track_sql_count

Parameter description: Collects statistics about the statements (SELECT, INSERT, UPDATE, MERGE INTO, and DELETE) that are being executed in a session.

In the x86-based centralized deployment scenario, the hardware configuration specifications are 32-core CPU and 256 GB memory. When the Benchmark SQL 5.0 tool is used to test performance, the performance fluctuates by about 0.8% by enabling or disabling this parameter.

This is a SUSET parameter. Set it based on instructions provided in Table 1.

Value range: Boolean

  • on indicates that the statistics collection function is enabled.
  • off indicates that the statistics collection function is disabled.

Default value: on

NOTE:
  • The track_sql_count parameter is restricted by the track_activities parameter.
    • If track_activities is set to on and track_sql_count is set to off, a warning message indicating that track_sql_count is disabled will be displayed in logs when the gs_sql_count view is queried.
    • If both track_activities and track_sql_count are set to off, two warning messages indicating that track_activities is disabled and track_sql_count is disabled will be displayed in logs when the views are queried.
    • If track_activities is set to off and track_sql_count is set to on, a warning message indicating that track_activities is disabled will be displayed in logs when the views are queried.
  • If this parameter is disabled, the query result is 0.

We use cookies to improve our site and your experience. By continuing to browse our site you accept our cookie policy. Find out more

Feedback

Feedback

Feedback

0/500

Selected Content

Submit selected content with the feedback