# Resource Pool Basics

This page explains how to create a new resource pool, modify an existing resource pool, how to show resource pool statuses, and introduces some built-in resource pools.

## Create a New Resource Pool

To create a new resource pool, run `CREATE RESOURCE POOL` from the master aggregator. For information on how to use this command, query execution behavior, and an example, see the [CREATE RESOURCE POOL](https://docs.singlestore.com/db/v9.1/reference/sql-reference/resource-pool-commands/create-resource-pool.md) topic.

## Modify an Existing Resource Pool

To modify an existing resource pool, run `ALTER RESOURCE POOL` from the master aggregator. For information on how to use this command and an example, see the [ALTER RESOURCE POOL](https://docs.singlestore.com/db/v9.1/reference/sql-reference/resource-pool-commands/alter-resource-pool.md) topic.

## `MV_RESOURCE_POOL_STATUS`

You can also show resource pool status across your pools with the [information\_schema.MV\_RESOURCE\_POOL\_STATUS](https://docs.singlestore.com/db/v9.1/reference/information-schema-reference/resource-and-user-management/mv-resource-pool-status.md) information\_schema table. The `MV_RESOURCE_POOL_STATUS` view collects data from all nodes. It will give active details about queued queries for resource pools that had set a maximum concurrency, as well as some historical data (killed, finished queries and total and average queue time).

```sql
SELECT * FROM information_schema.MV_RESOURCE_POOL_STATUS;

```

```output

+---------+-----------+-----------------+------------------+----------------+------------------+---------------------+-----------------------+
| NODE_ID | POOL_NAME | RUNNING_QUERIES | QUEUEING_QUERIES | KILLED_QUERIES | FINISHED_QUERIES | TOTAL_QUEUE_TIME_US | AVERAGE_QUEUE_TIME_US |
+---------+-----------+-----------------+------------------+----------------+------------------+---------------------+-----------------------+
|       3 | pool1     |               0 |                0 |              0 |                0 |                   0 |                     0 |
|       1 | pool1     |               0 |                0 |              0 |                0 |                   0 |                     0 |
|       2 | pool1     |               0 |                0 |              0 |                0 |                   0 |                     0 |
+---------+-----------+-----------------+------------------+----------------+------------------+---------------------+-----------------------+
```

For more information, see [ALTER RESOURCE POOL](https://docs.singlestore.com/db/v9.1/reference/sql-reference/resource-pool-commands/alter-resource-pool.md).

## The Built-in Resource Pools

Every cluster contains the built-in resource pools `system_optimizer_pool`, `default_pool`, and `system_auto`.

> **📝 Note**: For each user, `default_pool` is used unless a user-created resource pool has been assigned to the user.

The `system_optimizer_pool` runs when `enable_background_statistics_collection` is set to `ON`. If the `system_optimizer_pool` is running and the [resource\_governor\_cpu\_limit\_mode](https://docs.singlestore.com/db/v9.1/reference/sql-reference/resource-pool-commands/create-resource-pool.md) is set to `HARD`, the pool reserves 5% of CPU utilization for collection of background statistics.

By default, client connections to SingleStore use the `default_pool`. To use a different pool, see the next section, [Work with Resource Pool Engine Variables](https://docs.singlestore.com/db/v9.1/user-and-cluster-administration/use-the-workload-manager-and-set-resource-limits/set-resource-limits/work-with-resource-pool-engine-variables.md). Queries in the `default_pool` can have up to 100% of available query execution memory, up to 100% CPU utilization (depending on the [resource\_governor\_cpu\_limit\_mode](https://docs.singlestore.com/db/v9.1/reference/sql-reference/resource-pool-commands/create-resource-pool.md) setting), and do not have a timeout limit set or a defined number of concurrent queries.

***

Modified at: April 19, 2023

Source: [/db/v9.1/user-and-cluster-administration/use-the-workload-manager-and-set-resource-limits/set-resource-limits/resource-pool-basics/](https://docs.singlestore.com/db/v9.1/user-and-cluster-administration/use-the-workload-manager-and-set-resource-limits/set-resource-limits/resource-pool-basics/)

(An index of the documentation is available at /llms.txt)