ALTER RESOURCE POOL

Function

ALTER RESOURCE POOL changes the Cgroup of a resource pool.

Precautions

Users having the ALTER permission can modify resource pools.

Syntax

1
2

ALTER RESOURCE POOL pool_name
    WITH ({MEM_PERCENT=pct | CONTROL_GROUP="group_name" | ACTIVE_STATEMENTS=stmt | MAX_DOP = dop | MEMORY_LIMIT='memory_size' | io_limits=io_limits | io_priority='priority' | nodegroup='nodegroup_name' | except_rule='except_rule' | weight=bandwidth_weight | enable_concurrency_scaling=boolean}[, ... ]);

Parameter Description

• pool_name

  Specifies the name of the resource pool.

  The name of the resource pool is the name of an existing resource pool.

  Value range: a string. It must comply with the naming convention.

• group_name

  Specifies the name of a Cgroup.

  

  • You can use either double quotation marks ("") or single quotation mark ('') in the syntax when setting the name of a Cgroup.
  • The value of group_name is case-sensitive.
  • When group_name is not specified, the default value "Medium" is used. It is the "Medium" Timeshare Cgroup

    of the DefaultClass Cgroup.

  • If a database user specifies the Timeshare string (Rush, High, Medium, or Low) in the syntax, for example, if control_group is set to High, the resource pool will be associated with the High Timeshare Cgroup under DefaultClass.

  Value range: an existing control group.

• stmt

  Specifies the maximum number of statements that can be concurrently executed in a resource pool.

  Value range: Numeric data ranging from -1 to INT_MAX.

• dop

  Specifies the maximum number of simple SQL statements that can be concurrently executed in a resource pool.

  Value range: Numeric data ranging from -1 to INT_MAX.

• memory_size

  Specifies the maximum storage for a resource pool.

  Value range: a string, from 1KB to 2047GB.

• mem_percent

  Specifies the proportion of available resource pool memory to the total memory or group user memory.

  The value of mem_percent for a common user is an integer ranging from 0 to 100. The default value is 0.

• io_limits

  This parameter has been discarded in the 8.1.2 cluster version and is reserved for compatibility with earlier versions.

• io_priority

  This parameter has been discarded in the 8.1.2 cluster version and is reserved for compatibility with earlier versions.

• except_rule

  Name of an exception rule set

• weight

  Specifies the network bandwidth weight of the resource pool.

• enable_concurrency_scaling

  Specifies whether to enable the elastic concurrency expansion function. This function is supported only by clusters of version 9.1.0.100 or later.

  Value range:

  • true indicates that the elastic concurrent expansion function of jobs in the resource pool is enabled.
  • false indicates that the elastic concurrent expansion function of jobs in the resource pool is disabled.

  The default value is false.

Examples

Modify a resource pool, and associate it with the High Timeshare Cgroup under Workload under DefaultClass.

1

ALTER RESOURCE POOL pool1 WITH (CONTROL_GROUP="High");

Disable the elastic concurrent expansion function for jobs in a specified resource pool.

1

ALTER RESOURCE POOL pool6 WITH (enable_concurrency_scaling=false);

Helpful Links

CREATE RESOURCE POOL, DROP RESOURCE POOL