> ## Documentation Index
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> Use this file to discover all available pages before exploring further.

> System table containing information about setting changes in previous ClickHouse versions.

# system.settings_changes

<h2 id="description">
  Description
</h2>

Contains information about setting changes in previous ClickHouse versions.

<h2 id="columns">
  Columns
</h2>

* `type` ([Enum8('Session' = 0, 'MergeTree' = 1)](/reference/data-types)) — The group of settings (Session, MergeTree...)
* `version` ([String](/reference/data-types)) — The ClickHouse server version.
* `changes` ([Array(Tuple(name String, previous\_value String, new\_value String, reason String))](/reference/data-types)) — The list of changes in settings which changed the behaviour of ClickHouse.

<h2 id="example">
  Example
</h2>

```sql theme={null}
SELECT *
FROM system.settings_changes
WHERE version = '23.5'
FORMAT Vertical
```

```text theme={null}
Row 1:
──────
type:    Core
version: 23.5
changes: [('input_format_parquet_preserve_order','1','0','Allow Parquet reader to reorder rows for better parallelism.'),('parallelize_output_from_storages','0','1','Allow parallelism when executing queries that read from file/url/s3/etc. This may reorder rows.'),('use_with_fill_by_sorting_prefix','0','1','Columns preceding WITH FILL columns in ORDER BY clause form sorting prefix. Rows with different values in sorting prefix are filled independently'),('output_format_parquet_compliant_nested_types','0','1','Change an internal field name in output Parquet file schema.')]
```

<h2 id="see-also">
  See Also
</h2>

* [Settings](/reference/system-tables/overview#system-tables-introduction)
* [system.settings](/reference/system-tables/settings)