- Release Notes and Announcements
- Release Notes
- Announcements
- Announcement on Release of New Upgrade Mechanism for Kernel Minor Version
- Announcement on Optimization of Instance Storage Capacity, IOPS, and I/O Bandwidth
- Announcement on Some APIs with CAM Authentication Integrated
- Announcement on Sales Suspension of Some General Specifications
- Announcement on Some APIs Integrated with CAM Authentication
- Announcement on Some APIs with CAM Authentication Integrated
- Announcement on Change of Part of Parameters
- Announcement on Update of Database Audit Feature
- Announcement on Authentication of a Newly Added API Interface of Database Audit
- Announcement on Change of Public Network Linkage
- TDSQL-C for MySQL Audit Service Update
- Announcement on Supplementary Charge for Clusters with Pay-as-You-Go Storage Billing Mode
- Announcement on New APIs Integrated with CAM Permissions
- Announcement on the Release of New Version of Database Proxy
- Emergency Fix for Certain Monitoring Metrics
- Monitoring Metric Optimization
- Change to Database Audit Resource ID
- Ops Change
- Storage Price Adjustment Notification
- Beginner's Guide
- Product Introduction
- Kernel Features
- Kernel Overview
- Kernel Version Release Notes
- Optimized Kernel Version
- Functionality Features
- Performance Features
- Columns Syntax
- Correlated Subquery Result Cache
- Global Index
- Binlog Write Optimization
- Large Transaction Binlog Optimization
- Binlog Purging Performance Optimization
- Optimization of Plan Caching Point Query
- Auto-Increment Column Persistence
- Invisible Index
- Computation Pushdown
- Parallel Initialization of InnoDB Buffer Pool
- Security Features
- Stability Feature
- Purchase Guide
- Getting Started
- Database Audit
- Serverless Service
- Operation Guide
- Switching Cluster Page View in Console
- Database Connection
- Instance Management
- Configuration Adjustment
- Cluster Management
- Scaling Instance
- Database Proxy
- Database Proxy Overview
- Use Limits
- Database Proxy Kernel Features
- Managing Database Proxy
- Enabling Database Proxy
- Setting Database Proxy Address
- Modifying or Deleting Connection Addresses
- Viewing and Changing the Access Policy
- Rebalancing the Load
- Transaction Split Feature
- Access Mode
- Adjusting Database Proxy Configuration
- Switching Database Proxy Network
- Viewing Database Proxy Monitoring Data
- Disabling Database Proxy
- Automatic Read/Write Separation
- Connection Pool Feature
- Other Features
- Account Management
- Database Management
- Database Management Tool
- Columnar Storage Index (CSI)
- Parameter Configuration
- Multi-AZ Deployment
- Backup and Restoration
- Operation Log
- Data Migration
- Parallel Query
- Database Security and Encryption
- Monitoring and Alarms
- Basic SQL Operations
- Connecting to TDSQL-C for MySQL Through SCF
- Tag
- Practical Tutorial
- Classified Protection Practice for Database Audit of TDSQL-C for MySQL
- Upgrading Database Version from MySQL 5.7 to 8.0 Through DTS
- Usage Instructions for TDSQL-C MySQL
- New Version of Console
- Implementing Multiple RO Groups with Multiple Database Proxy Connection Addresses
- Strengths of Database Proxy
- Selecting Billing Mode for Storage Space
- Creating Remote Disaster Recovery by DTS
- Creating VPC for Cluster
- Data Rollback
- Solution to High CPU Utilization
- How to Authorize Sub-Users to View Monitoring Data
- White Paper
- API Documentation
- History
- Introduction
- API Category
- Making API Requests
- Billing APIs
- Instance APIs
- CloseClusterPasswordComplexity
- CopyClusterPasswordComplexity
- DescribeClusterDetail
- DescribeClusterPasswordComplexity
- ModifyClusterPasswordComplexity
- OpenClusterPasswordComplexity
- UpgradeClusterVersion
- UpgradeInstance
- SetRenewFlag
- OfflineCluster
- ModifyMaintainPeriodConfig
- IsolateInstance
- IsolateCluster
- DescribeMaintainPeriod
- DescribeInstanceSpecs
- DescribeClusters
- CreateClusters
- AddInstances
- OfflineInstance
- DescribeInstanceDetail
- DescribeClusterInstanceGrps
- DescribeInstances
- ActivateInstance
- ModifyInstanceName
- ModifyClusterName
- SearchClusterTables
- SearchClusterDatabases
- RestartInstance
- Multi-AZ APIs
- Account APIs
- Audit APIs
- Database Proxy APIs
- Backup and Restoration APIs
- Parameter Management APIs
- Performance Analysis APIs
- Serverless APIs
- ResourcePackage APIs
- Other APIs
- CloseWan
- CreateClusterDatabase
- DeleteClusterDatabase
- DescribeClusterDetailDatabases
- ModifyClusterDatabase
- OpenWan
- SwitchClusterVpc
- OpenReadOnlyInstanceExclusiveAccess
- OpenClusterReadOnlyInstanceGroupAccess
- ModifyDBInstanceSecurityGroups
- DescribeProjectSecurityGroups
- DescribeDBSecurityGroups
- SwitchProxyVpc
- DescribeFlow
- DescribeZones
- ModifyVipVport
- Data Types
- Error Codes
- FAQs
- Service Agreement
- TDSQL-C Policy
- General References
- Glossary
- Contact Us
- Release Notes and Announcements
- Release Notes
- Announcements
- Announcement on Release of New Upgrade Mechanism for Kernel Minor Version
- Announcement on Optimization of Instance Storage Capacity, IOPS, and I/O Bandwidth
- Announcement on Some APIs with CAM Authentication Integrated
- Announcement on Sales Suspension of Some General Specifications
- Announcement on Some APIs Integrated with CAM Authentication
- Announcement on Some APIs with CAM Authentication Integrated
- Announcement on Change of Part of Parameters
- Announcement on Update of Database Audit Feature
- Announcement on Authentication of a Newly Added API Interface of Database Audit
- Announcement on Change of Public Network Linkage
- TDSQL-C for MySQL Audit Service Update
- Announcement on Supplementary Charge for Clusters with Pay-as-You-Go Storage Billing Mode
- Announcement on New APIs Integrated with CAM Permissions
- Announcement on the Release of New Version of Database Proxy
- Emergency Fix for Certain Monitoring Metrics
- Monitoring Metric Optimization
- Change to Database Audit Resource ID
- Ops Change
- Storage Price Adjustment Notification
- Beginner's Guide
- Product Introduction
- Kernel Features
- Kernel Overview
- Kernel Version Release Notes
- Optimized Kernel Version
- Functionality Features
- Performance Features
- Columns Syntax
- Correlated Subquery Result Cache
- Global Index
- Binlog Write Optimization
- Large Transaction Binlog Optimization
- Binlog Purging Performance Optimization
- Optimization of Plan Caching Point Query
- Auto-Increment Column Persistence
- Invisible Index
- Computation Pushdown
- Parallel Initialization of InnoDB Buffer Pool
- Security Features
- Stability Feature
- Purchase Guide
- Getting Started
- Database Audit
- Serverless Service
- Operation Guide
- Switching Cluster Page View in Console
- Database Connection
- Instance Management
- Configuration Adjustment
- Cluster Management
- Scaling Instance
- Database Proxy
- Database Proxy Overview
- Use Limits
- Database Proxy Kernel Features
- Managing Database Proxy
- Enabling Database Proxy
- Setting Database Proxy Address
- Modifying or Deleting Connection Addresses
- Viewing and Changing the Access Policy
- Rebalancing the Load
- Transaction Split Feature
- Access Mode
- Adjusting Database Proxy Configuration
- Switching Database Proxy Network
- Viewing Database Proxy Monitoring Data
- Disabling Database Proxy
- Automatic Read/Write Separation
- Connection Pool Feature
- Other Features
- Account Management
- Database Management
- Database Management Tool
- Columnar Storage Index (CSI)
- Parameter Configuration
- Multi-AZ Deployment
- Backup and Restoration
- Operation Log
- Data Migration
- Parallel Query
- Database Security and Encryption
- Monitoring and Alarms
- Basic SQL Operations
- Connecting to TDSQL-C for MySQL Through SCF
- Tag
- Practical Tutorial
- Classified Protection Practice for Database Audit of TDSQL-C for MySQL
- Upgrading Database Version from MySQL 5.7 to 8.0 Through DTS
- Usage Instructions for TDSQL-C MySQL
- New Version of Console
- Implementing Multiple RO Groups with Multiple Database Proxy Connection Addresses
- Strengths of Database Proxy
- Selecting Billing Mode for Storage Space
- Creating Remote Disaster Recovery by DTS
- Creating VPC for Cluster
- Data Rollback
- Solution to High CPU Utilization
- How to Authorize Sub-Users to View Monitoring Data
- White Paper
- API Documentation
- History
- Introduction
- API Category
- Making API Requests
- Billing APIs
- Instance APIs
- CloseClusterPasswordComplexity
- CopyClusterPasswordComplexity
- DescribeClusterDetail
- DescribeClusterPasswordComplexity
- ModifyClusterPasswordComplexity
- OpenClusterPasswordComplexity
- UpgradeClusterVersion
- UpgradeInstance
- SetRenewFlag
- OfflineCluster
- ModifyMaintainPeriodConfig
- IsolateInstance
- IsolateCluster
- DescribeMaintainPeriod
- DescribeInstanceSpecs
- DescribeClusters
- CreateClusters
- AddInstances
- OfflineInstance
- DescribeInstanceDetail
- DescribeClusterInstanceGrps
- DescribeInstances
- ActivateInstance
- ModifyInstanceName
- ModifyClusterName
- SearchClusterTables
- SearchClusterDatabases
- RestartInstance
- Multi-AZ APIs
- Account APIs
- Audit APIs
- Database Proxy APIs
- Backup and Restoration APIs
- Parameter Management APIs
- Performance Analysis APIs
- Serverless APIs
- ResourcePackage APIs
- Other APIs
- CloseWan
- CreateClusterDatabase
- DeleteClusterDatabase
- DescribeClusterDetailDatabases
- ModifyClusterDatabase
- OpenWan
- SwitchClusterVpc
- OpenReadOnlyInstanceExclusiveAccess
- OpenClusterReadOnlyInstanceGroupAccess
- ModifyDBInstanceSecurityGroups
- DescribeProjectSecurityGroups
- DescribeDBSecurityGroups
- SwitchProxyVpc
- DescribeFlow
- DescribeZones
- ModifyVipVport
- Data Types
- Error Codes
- FAQs
- Service Agreement
- TDSQL-C Policy
- General References
- Glossary
- Contact Us
Feature Overview
Each time when a correlated subquery is executed, it is necessary to recalculate results of the subquery. This may lead to lower performance. TXSQL currently supports the correlated subquery result cache (subquery cache) feature, which enables caching of subquery results to avoid repetitive calculation and improve the query performance.
Supported Versions
The kernel version should be 3.1.15 or later for TXSQL 8.0.
Applicable Scenarios
It is applicable to scenarios where many correlated subqueries are executed and the query performance needs improvement.
Use Instructions
Parameter Name | Dynamic | Type | Default Value | Valid Values/Value Range | Description |
txsql_subquery_cache_enabled | yes | Boolean | OFF | ON/OFF | Controls whether to enable the subquery cache feature. |
txsql_subquery_cache_cost_threshold | yes | Integer | 4000 | 0-DBL_MAX | Execution cost threshold for the subquery cache feature. The subquery cache feature is used only for correlated subqueries with an estimated execution cost higher than this threshold. |
New Status Parameters
New status parameters are used to describe the hit status of the subquery cache, including Txsql_subquery_cache_hit and Txsql_subquery_cache_miss.
You can observe the partial result cache plan using
explain format=tree.
Yes
No
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