> ## 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.

# database_* session settings

> ClickHouse session settings in the database_* 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="database_atomic_wait_for_drop_and_detach_synchronously">
  database\_atomic\_wait\_for\_drop\_and\_detach\_synchronously
</h2>

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

Adds a modifier `SYNC` to all `DROP` and `DETACH` queries.

Possible values:

* 0 — Queries will be executed with delay.
* 1 — Queries will be executed without delay.

<h2 id="database_datalake_require_metadata_access">
  database\_datalake\_require\_metadata\_access
</h2>

<SettingsInfoBlock type="Bool" default_value="1" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.1"},{"label": "1"},{"label": "New setting."}]}]} />

Either to throw error or not if we don't have rights to get table's metadata in database engine DataLakeCatalog.

<h2 id="database_shared_drop_table_delay_seconds">
  database\_shared\_drop\_table\_delay\_seconds
</h2>

<SettingsInfoBlock type="UInt64" default_value="28800" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.11"},{"label": "28800"},{"label": "New setting."}]}]} />

The delay in seconds before a dropped table is actually removed from a Shared database. This allows to recover the table within this time using `UNDROP TABLE` statement.