Parameter settings-PolarDB(PolarDB)-阿里云帮助中心

You can use the PolarDB-X 1.0 console to view and modify parameters for your instances and databases.

Usage notes

Read-only instances support only Database parameters, not Instance parameters.
Some parameters are available only for specific instance versions. For more information, see Parameter descriptions.

Parameters

Level	Parameter	Description	Supported version
Instance-level	SLOW_SQL_TIME	The threshold for slow SQL queries. SQL queries that exceed this threshold are recorded in the logical slow SQL log.	This parameter is supported on instance version 5.3.4-15378085 or later. For more information about instance versions, see Instance versions.
	LOGIC_IDLE_TIMEOUT	The idle timeout for a connection between a client and a PolarDB-X 1.0 instance. Unit: milliseconds (ms).	This parameter is supported on instance version 5.3.4-15378085 or later. For more information about instance versions, see Instance versions.
	MAX_ALLOWED_PACKET	The maximum size of a network packet between a client and a PolarDB-X 1.0 instance. Unit: bytes.	This parameter is supported on instance version 5.3.4-15378085 or later. For more information about instance versions, see Instance versions.
Database-level	MAX_POOL_SIZE	The maximum number of connections between a PolarDB-X 1.0 compute node and a single physical shard on the storage layer.	All versions
	MIN_POOL_SIZE	The minimum number of connections between a PolarDB-X 1.0 compute node and a single physical shard on the storage layer.	All versions
	IDLE_TIMEOUT	The idle timeout for a connection between a PolarDB-X 1.0 compute node and a storage layer node. Unit: ms.	All versions
	SOCKET_TIMEOUT	The timeout for SQL queries between a PolarDB-X 1.0 compute node and a storage layer node. Unit: ms.	All versions
	FORBID_EXECUTE_DML_ALL	Specifies whether to block DELETE or UPDATE operations that affect an entire table.	All versions
	TEMP_TABLE_MAX_ROWS	The maximum number of rows in a temporary table that is used during a distributed query in PolarDB-X 1.0.	This parameter is supported on instance version 5.3.4-15378085 or later. For more information about instance versions, see Instance versions.
	MERGE_UNION_SIZE	The maximum number of table shards that can be merged by using UNION in a single query.	This parameter is supported on instance version 5.3.4-15378085 or later. For more information about instance versions, see Instance versions.
	PURE_ASYNC_DDL_MODE	Specifies whether to enable the pure asynchronous mode for the asynchronous DDL engine. If you enable this mode, the client receives an immediate response after a DDL task is submitted to the PolarDB-X 1.0 instance. You can check the execution status of the DDL task only by using asynchronous DDL management statements. If you disable this mode (synchronous mode), the client waits until the DDL statement is fully executed before it receives a response.	This parameter is supported on instance version 5.3.4-15378085 or later. For more information about instance versions, see Instance versions.
	ENABLE_RANDOM_PHY_TABLE_NAME	Specifies whether to use randomly generated names for physical tables.	This parameter is supported on instance version 5.4.4 or later. For more information about instance versions, see Instance versions.

Procedure

Log on to the PolarDB-X 1.0 console.
In the top navigation bar, select the region where the instance is deployed.
In the left-side navigation pane, click Instances.
Find the target instance and click the instance ID.
In the navigation pane on the left, click Diagnostics and Optimization > Parameter Settings. You can modify parameters on the Instance or Database tab.
- Modify Instance parameters
  1. On the Instance tab, find the parameter that you want to modify and click the Edit icon in the Parameter Value column.
    Note You can click the ? icon in the Description column to view parameter details.
  2. In the dialog box, enter a new value and click OK.
    Note The value must be within the range specified in the Valid Values column. Otherwise, an error message appears when you click Submit.
- Modify Database parameters
  1. Click the Database tab and select your target database.
  2. Find the parameter that you want to modify and click the Edit icon in the Parameter Value column.
    Note You can click the ? icon in the Description column to view parameter details.
  3. In the dialog box, enter a new value and click OK.
    Note The value must be within the range specified in the Valid Values column. Otherwise, an error message appears when you click Submit.
After modifying Parameter Values, click Submit in the upper-right corner.

Note If a parameter has Yes in the Restart column, you must restart the instance after clicking Submit for the new Parameter Value to take effect.