> ## Documentation Index
> Fetch the complete documentation index at: https://clickhouse.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# postgresql_connection_* session settings

> ClickHouse session settings in the postgresql_connection_* generated group.

export const SettingsInfoBlock = ({type, default_value, changeable_without_restart}) => {
  return <div className="not-prose" style={{
    display: "flex",
    flexWrap: "wrap",
    alignItems: "baseline",
    columnGap: "0.5rem",
    rowGap: "0.125rem",
    margin: "0.375rem 0",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <div style={{
    fontWeight: 600,
    opacity: 0.72
  }}>Type</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{type}</div>
      <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>Default</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{default_value}</div>
      {changeable_without_restart && <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>
          Changeable without restart
        </div>}
      {changeable_without_restart && <div style={{
    overflowWrap: "anywhere"
  }}>
          {changeable_without_restart}
        </div>}
    </div>;
};

These settings are available in [system.settings](/docs/reference/system-tables/settings) and are autogenerated from [source](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp).

<h2 id="postgresql_connection_attempt_timeout">
  postgresql\_connection\_attempt\_timeout
</h2>

<SettingsInfoBlock type="UInt64" default_value="2" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "24.7"},{"label": "2"},{"label": "Allow to control 'connect_timeout' parameter of PostgreSQL connection."}]}]} />

Connection timeout in seconds of a single attempt to connect PostgreSQL end-point.
The value is passed as a `connect_timeout` parameter of the connection URL.

<h2 id="postgresql_connection_pool_auto_close_connection">
  postgresql\_connection\_pool\_auto\_close\_connection
</h2>

<SettingsInfoBlock type="Bool" default_value="0" />

Close connection before returning connection to the pool.

<h2 id="postgresql_connection_pool_retries">
  postgresql\_connection\_pool\_retries
</h2>

<SettingsInfoBlock type="UInt64" default_value="2" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "24.7"},{"label": "2"},{"label": "Allow to control the number of retries in PostgreSQL connection pool."}]}]} />

Connection pool push/pop retries number for PostgreSQL table engine and database engine.

<h2 id="postgresql_connection_pool_size">
  postgresql\_connection\_pool\_size
</h2>

<SettingsInfoBlock type="UInt64" default_value="16" />

Connection pool size for PostgreSQL table engine and database engine.

<h2 id="postgresql_connection_pool_wait_timeout">
  postgresql\_connection\_pool\_wait\_timeout
</h2>

<SettingsInfoBlock type="UInt64" default_value="5000" />

Connection pool push/pop timeout on empty pool for PostgreSQL table engine and database engine. By default it will block on empty pool.