> ## 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.

# s3queue_* server settings

> ClickHouse server settings in the s3queue_* 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 configure the ClickHouse server and are autogenerated from ClickHouse source.

<h2 id="s3queue_disable_streaming">
  s3queue\_disable\_streaming
</h2>

<SettingsInfoBlock type="Bool" default_value="0" changeable_without_restart="Yes" />Disable streaming in S3Queue even if the table is created and there are attached materiaized views

<h2 id="s3queue_log">
  s3queue\_log
</h2>

Settings for the `s3queue_log` system table.

The following settings can be configured by sub-tags:

| Setting                            | Description                                                                                                                                            | Default             | Note                                                                                                               |
| ---------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------- | ------------------------------------------------------------------------------------------------------------------ |
| `database`                         | Name of the database.                                                                                                                                  |                     |                                                                                                                    |
| `table`                            | Name of the system table.                                                                                                                              |                     |                                                                                                                    |
| `engine`                           | [MergeTree Engine Definition](/docs/reference/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-creating-a-table) for a system table. |                     | Cannot be used if `partition_by` or `order_by` defined. If not specified `MergeTree` is selected by default        |
| `partition_by`                     | [Custom partitioning key](/docs/reference/engines/table-engines/mergetree-family/custom-partitioning-key) for a system table.                               |                     | If `engine` is specified for system table, `partition_by` parameter should be specified directly inside 'engine'   |
| `ttl`                              | Specifies the table [TTL](/docs/reference/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-ttl).                                     |                     | If `engine` is specified for system table, `ttl` parameter should be specified directly inside 'engine'            |
| `order_by`                         | [Custom sorting key](/docs/reference/engines/table-engines/mergetree-family/mergetree#order_by) for a system table. Can't be used if `engine` defined.      |                     | If `engine` is specified for system table, `order_by` parameter should be specified directly inside 'engine'       |
| `storage_policy`                   | Name of the storage policy to use for the table (optional).                                                                                            |                     | If `engine` is specified for system table, `storage_policy` parameter should be specified directly inside 'engine' |
| `settings`                         | [Additional parameters](/docs/reference/engines/table-engines/mergetree-family/mergetree#settings) that control the behavior of the MergeTree (optional).   |                     | If `engine` is specified for system table, `settings` parameter should be specified directly inside 'engine'       |
| `flush_interval_milliseconds`      | Interval for flushing data from the buffer in memory to the table.                                                                                     | `7500`              |                                                                                                                    |
| `max_size_rows`                    | Maximal size in lines for the logs. When the amount of non-flushed logs reaches the max\_size, logs are dumped to the disk.                            | `1048576`           |                                                                                                                    |
| `reserved_size_rows`               | Pre-allocated memory size in lines for the logs.                                                                                                       | `8192`              |                                                                                                                    |
| `buffer_size_rows_flush_threshold` | Threshold for amount of lines. If the threshold is reached, flushing logs to the disk is launched in background.                                       | `max_size_rows / 2` |                                                                                                                    |
| `flush_on_crash`                   | Sets whether logs should be dumped to the disk in case of a crash.                                                                                     | `false`             |                                                                                                                    |

Additionally, the following server-level setting controls the default flush policy for all system log tables:

```xml theme={null}
<default_system_log_flush_policy>
    <skip_alias_columns>true</skip_alias_columns>
</default_system_log_flush_policy>
```

| Setting              | Description                                                                                               | Default |
| -------------------- | --------------------------------------------------------------------------------------------------------- | ------- |
| `skip_alias_columns` | When `true`, ALIAS columns are omitted from system log table schemas. Required for S3-backed system logs. | `false` |

The default settings are:

```xml theme={null}
<s3queue_log>
    <database>system</database>
    <table>s3queue_log</table>
    <partition_by>toYYYYMM(event_date)</partition_by>
    <flush_interval_milliseconds>7500</flush_interval_milliseconds>
</s3queue_log>
```