settings_changes

Contains information about setting changes in previous ClickHouse versions.

Columns:

• type (Enum) - The settings type: Core (general / query settings), MergeTree.
• version (String) — The ClickHouse version in which settings were changed
• changes (Array of Tuple) — A description of the setting changes: (setting name, previous value, new value, reason for the change)

Example

SELECT *
FROM system.settings_changes
WHERE version = '23.5'
FORMAT Vertical

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.')]

See also

• Settings
• system.settings