---
id: 'pg_stat_statements'
title: 'pg_stat_statements: Query Performance Monitoring'
description: 'Track planning and execution statistics of all SQL statements executed on the database.'
---

`pg_stat_statements` is a database extension that exposes a view, of the same name, to track statistics about SQL statements executed on the database. The following table shows some of the available statistics and metadata:

| Column Name       | Column Type                          | Description                                                                                                                  |
| ----------------- | ------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------- |
| `userid`          | `oid` (references `pg_authid.oid`)   | OID of user who executed the statement                                                                                       |
| `dbid`            | `oid` (references `pg_database.oid`) | OID of database in which the statement was executed                                                                          |
| `toplevel`        | `bool`                               | True if the query was executed as a top-level statement (always true if pg_stat_statements.track is set to top)              |
| `queryid`         | `bigint`                             | Hash code to identify identical normalized queries.                                                                          |
| `query`           | `text`                               | Text of a representative statement                                                                                           |
| `plans`           | `bigint`                             | Number of times the statement was planned (if pg_stat_statements.track_planning is enabled, otherwise zero)                  |
| `total_plan_time` | `double precision`                   | Total time spent planning the statement, in milliseconds (if pg_stat_statements.track_planning is enabled, otherwise zero)   |
| `min_plan_time`   | `double precision`                   | Minimum time spent planning the statement, in milliseconds (if pg_stat_statements.track_planning is enabled, otherwise zero) |

A full list of statistics is available in the [pg_stat_statements docs](https://www.postgresql.org/docs/current/pgstatstatements.html).

For more information on query optimization, check out the [query performance guide](/docs/guides/platform/performance#examining-query-performance).

## Enable the extension

<Tabs
  scrollable
  size="small"
  type="underlined"
  defaultActiveId="dashboard"
  queryGroup="database-method"
>
<TabPanel id="dashboard" label="Dashboard">

1. Go to the [Database](https://supabase.com/dashboard/project/_/database/tables) page in the Dashboard.
2. Click on **Extensions** in the sidebar.
3. Search for "pg_stat_statements" and enable the extension.

</TabPanel>
<TabPanel id="sql" label="SQL">

{/* prettier-ignore */}
```sql
-- Enable the "pg_stat_statements" extension
create extension pg_stat_statements with schema extensions;

-- Disable the "pg_stat_statements" extension
drop extension if exists pg_stat_statements;
```

Even though the SQL code is `create extension`, this is the equivalent of "enabling the extension".
To disable an extension you can call `drop extension`.

It's good practice to create the extension within a separate schema (like `extensions`) to keep the `public` schema clean.

</TabPanel>
</Tabs>

## Inspecting activity

A common use for `pg_stat_statements` is to track down expensive or slow queries. The `pg_stat_statements` view contains a row for each executed query with statistics inlined. For example, you can leverage the statistics to identify frequently executed and slow queries against a given table.

{/* prettier-ignore */}
```sql
select
	calls,
	mean_exec_time,
	max_exec_time,
	total_exec_time,
	stddev_exec_time,
	query
from
	pg_stat_statements
where
    calls > 50                   -- at least 50 calls
    and mean_exec_time > 2.0     -- averaging at least 2ms/call
    and total_exec_time > 60000  -- at least one minute total server time spent
    and query ilike '%user_in_organization%' -- filter to queries that touch the user_in_organization table
order by
	calls desc
```

From the results, we can make an informed decision about which queries to optimize or index.

## Resources

- Official [pg_stat_statements documentation](https://www.postgresql.org/docs/current/pgstatstatements.html)