ALTER RESOURCE POOL

Modifies an existing resource pool by setting one or more parameters.

You can use ALTER RESOURCE POOL to modify some parameters in Vertica built-in resource pools. For details on default settings and restrictions, see Built-in resource pools configuration.

Important

Changes to parameters of the built-in GENERAL resource pool take effect only when the database restarts.

Syntax

ALTER RESOURCE POOL pool-name [ FOR subcluster ] parameter-name setting[...]

Arguments

pool-name

Name of the resource pool to modify.

FOR subcluster

Eon Mode only, the subcluster to associate with this resource pool, where subcluster is one of the following:

SUBCLUSTER subcluster-name: Resource pool for an existing subcluster. You cannot be connected to this subcluster, otherwise Vertica returns an error.
CURRENT SUBCLUSTER: Resource pool for the subcluster that you are connected to.

Important

You cannot use ALTER RESOURCE POOL to convert a global resource pool to a subcluster-level resource pool.

parameter-name setting

A resource pool parameter and its new setting. To reset this parameter to its default value, specify DEFAULT.

If you specify a subcluster, you can alter only the MAXMEMORYSIZE, MAXQUERYMEMORYSIZE, and MEMORYSIZE parameters for built-in pools.

Parameters

Note

Default values specified here pertain only to user-defined resource pools. For built-in pool default values, see Built-in resource pools configuration, or query system table RESOURCE_POOL_DEFAULTS.

CASCADE TO

Secondary resource pool for executing queries that exceed the RUNTIMECAP setting of their assigned resource pool:

CASCADE TO secondary-pool

CPUAFFINITYMODE

Specifies whether the resource pool has exclusive or shared use of the CPUs specified in CPUAFFINITYSET:

CPUAFFINITYMODE { SHARED | EXCLUSIVE | ANY }

SHARED: Queries that run in this resource pool share its CPUAFFINITYSET CPUs with other Vertica resource pools.
EXCLUSIVE: Dedicates CPUAFFINITYSET CPUs to this resource pool only, and excludes other Vertica resource pools. If CPUAFFINITYSET is set as a percentage, then that percentage of CPU resources available to Vertica is assigned solely for this resource pool.
ANY: Queries in this resource pool can run on any CPU, invalid if CPUAFFINITYSET designates CPU resources.

Default: ANY

CPUAFFINITYSET

CPUs available to this resource pool. All cluster nodes must have the same number of CPUs. The CPU resources assigned to this set are unavailable to general resource pools.

CPUAFFINITYSET {
  'cpu-index[,...]'
| 'cpu-indexi-cpu-indexn'
| 'integer%'
| NONE
}

cpu-index[,...]: Dedicates one or more comma-delimited CPUs to this resource pool.
cpu-indexi-cpu-indexn: Dedicates a range of contiguous CPU indexes i through n to this resource pool.
integer%: Percentage of all available CPUs to use for this resource pool. Vertica rounds this percentage down to include whole CPU units.
NONE (empty string): No affinity set is assigned to this resource pool. Queries associated with this pool are executed on any CPU.

Default: NONE

Important

CPUAFFINITYSET and CPUAFFINITYMODE must be set together in the same statement.

EXECUTIONPARALLELISM

Number of threads used to process any single query issued in this resource pool.

EXECUTIONPARALLELISM { limit | AUTO }

limit: An integer value between 1 and the number of cores. Setting this parameter to a reduced value increases throughput of short queries issued in the resource pool, especially if queries are executed concurrently.
AUTO or 0: Vertica calculates the setting from the number of cores, available memory, and amount of data in the system. Unless memory is limited, or the amount of data is very small, Vertica sets this parameter to the number of cores on the node.

Default: AUTO

MAXCONCURRENCY

Maximum number of concurrent execution slots available to the resource pool across the cluster:

MAXCONCURRENCY { integer | NONE }

NONE (empty string): Unlimited number of concurrent execution slots.

Default: NONE

MAXMEMORYSIZE

Maximum size per node the resource pool can grow by borrowing memory from the GENERAL pool:

MAXMEMORYSIZE {
  'integer%'
  |'integer{K|M|G|T}'
  NONE
}

integer%: Percentage of total memory
integer{K|M|G|T}: Amount of memory in kilobytes, megabytes, gigabytes, or terabytes
NONE (empty string): Unlimited, resource pool can borrow any amount of available memory from the GENERAL pool.

Default: NONE

MAXQUERYMEMORYSIZE

Maximum amount of memory this resource pool can allocate at runtime to process a query. If the query requires more memory than this setting, Vertica stops execution and returns an error.

Set this parameter as follows:

MAXQUERYMEMORYSIZE {
  'integer%'
| 'integer{K|M|G|T}'
| NONE
}

integer%: Percentage of MAXMEMORYSIZE for this resource pool.
integer{K|M|G|T}: Amount of memory in kilobytes, megabytes, gigabytes, or terabytes, up to the value of MAXMEMORYSIZE.
NONE (empty string): Unlimited; resource pool can borrow any amount of available memory from the GENERAL pool, within the limits set by MAXMEMORYSIZE.

Default: NONE

Important

Changes to MAXQUERYMEMORYSIZE are applied retroactively to queries that are currently executing. If you reduce this setting, queries that were budgeted with the previous memory size are liable to fail if they try to allocate more memory than the new setting allows.

MEMORYSIZE

Total per-node memory available to the Vertica resource manager that is allocated to this resource pool:

MEMORYSIZE {
  'integer%'
| 'integer{K|M|G|T}'
}

integer%: Percentage of total memory
integer{K|M|G|T}: Amount of memory in kilobytes, megabytes, gigabytes, or terabytes

Default: 0%. No memory allocated, the resource pool borrows memory from the GENERAL pool.

PLANNEDCONCURRENCY

Preferred number of queries to execute concurrently in the resource pool. This setting applies to the entire cluster:

PLANNEDCONCURRENCY { num-queries | AUTO }

num-queries: Integer value ≥ 1, the preferred number of queries to execute concurrently in the resource pool. When possible, query resource budgets are limited to allow this level of concurrent execution.
AUTO: Value is calculated automatically at query runtime. Vertica sets this parameter to the lower of these two calculations, but never less than 4:
- Number of logical cores
- Memory divided by 2GB
If the number of logical cores on each node is different, AUTO is calculated differently for each node. Distributed queries run like the minimal effective planned concurrency. Single node queries run with the planned concurrency of the initiator.

Default: AUTO

Tip

Change this parameter only after evaluating performance over a period of time.

PRIORITY

Priority of queries in this resource pool when they compete for resources in the GENERAL pool:

PRIORITY { integer | HOLD }

integer: Negative or positive integer value, where higher numbers denote higher priority:
- User-defined resource pool: -100 to 100
- Built-in resource pools SYSQUERY, RECOVERY, and TM: -110 to 110
HOLD: Sets priority to -999. Queries in this resource pool are queued until QUEUETIMEOUT is reached.

Default: 0

QUEUETIMEOUT

Maximum time a request can wait for pool resources before it is rejected, not more than one year:

QUEUETIMEOUT { integer | 'interval' | 'NONE' }

integer: Maximum wait time in seconds
[interval](/en/sql-reference/language-elements/literals/datetime-literals/interval-literal/): Maximum wait time expressed in the following format:
```
num year num months num [days] HH:MM:SS.ms
```
NONE (empty string): No maximum wait time, request can be queued indefinitely, up to one year.

If the value that you specify resolves to more than one year, Vertica returns with a warning and sets the parameter to 365 days:

=> ALTER RESOURCE POOL user_0 QUEUETIMEOUT '11 months 50 days 08:32';
WARNING 5693:  Using 1 year for QUEUETIMEOUT
ALTER RESOURCE POOL
=> SELECT QUEUETIMEOUT FROM resource_pools WHERE name = 'user_0';
 QUEUETIMEOUT
--------------
 365
(1 row)

Default: 00:05 (5 minutes)

RUNTIMECAP

Maximum execution time allowed to queries in this resource pool, not more than one year, otherwise Vertica returns with an error. If a query exceeds this setting, it tries to cascade to a secondary pool:

RUNTIMECAP { 'interval' | NONE }

interval: Maximum wait time expressed in the following format:
```
num year num month num [day] HH:MM:SS.ms
```
NONE (empty string): No maximum wait time, request can be queued indefinitely, up to one year.

If the user or session also has a RUNTIMECAP, the shorter limit applies.

RUNTIMEPRIORITY

Determines how the resource manager should prioritize dedication of run-time resources (CPU, I/O bandwidth) to queries already running in this resource pool:

RUNTIMEPRIORITY { HIGH | MEDIUM | LOW }

Default: MEDIUM

RUNTIMEPRIORITYTHRESHOLD

Maximum time (in seconds) in which query processing must complete before the resource manager assigns to it the resource pool's RUNTIMEPRIORITY. All queries begin execution with a priority of HIGH.

RUNTIMEPRIORITYTHRESHOLD seconds

Default: 2

SINGLEINITIATOR

Set to false for backward compatibility. Do not change this setting.

Privileges

Superuser

Examples

Set resource pool PRIORITY to 5:

=> ALTER RESOURCE POOL ceo_pool PRIORITY 5;

Designate a secondary resource pool:

=> CREATE RESOURCE POOL second_pool;
=> ALTER RESOURCE POOL ceo_pool CASCADE TO second_pool;

Decrease to 0% the MAXMEMORYSIZE and MEMORYSIZE settings on the dashboard subcluster's built-in TM resource pool. Changing these settings to 0 prevents the subcluster from running mergeout operations:

=> ALTER RESOURCE POOL TM FOR SUBCLUSTER dashboard MEMORYSIZE '0%'
   MAXMEMORYSIZE '0%';

See Tuning tuple mover pool settings for more information.

ALTER RESOURCE POOL

Important

Syntax

Arguments

Important

Parameters

Note

Important

Important

Tip

Privileges

Examples

See also