ClickHouse/docs/en/operations/system-tables/merge_tree_settings.md
2020-12-03 13:48:02 -08:00

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system.merge_tree_settings

Contains information about settings for MergeTree tables.

Columns:

  • name (String) — Setting name.
  • value (String) — Setting value.
  • description (String) — Setting description.
  • type (String) — Setting type (implementation specific string value).
  • changed (UInt8) — Whether the setting was explicitly defined in the config or explicitly changed.

Example

:) SELECT * FROM system.merge_tree_settings LIMIT 4 FORMAT Vertical;
Row 1:
──────
name:        index_granularity
value:       8192
changed:     0
description: How many rows correspond to one primary key value.
type:        SettingUInt64

Row 2:
──────
name:        min_bytes_for_wide_part
value:       0
changed:     0
description: Minimal uncompressed size in bytes to create part in wide format instead of compact
type:        SettingUInt64

Row 3:
──────
name:        min_rows_for_wide_part
value:       0
changed:     0
description: Minimal number of rows to create part in wide format instead of compact
type:        SettingUInt64

Row 4:
──────
name:        merge_max_block_size
value:       8192
changed:     0
description: How many rows in blocks should be formed for merge operations.
type:        SettingUInt64

4 rows in set. Elapsed: 0.001 sec. 

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