2020-08-06 08:50:29 +00:00
|
|
|
# system.merge_tree_settings {#system-merge_tree_settings}
|
2020-06-18 08:24:31 +00:00
|
|
|
|
|
|
|
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.
|
2020-08-06 08:50:29 +00:00
|
|
|
|
2020-12-03 19:27:55 +00:00
|
|
|
**Example**
|
|
|
|
```sql
|
|
|
|
:) SELECT * FROM system.merge_tree_settings LIMIT 4 FORMAT Vertical;
|
|
|
|
```
|
|
|
|
|
|
|
|
```text
|
|
|
|
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.
|
|
|
|
```
|
2020-12-03 21:44:17 +00:00
|
|
|
|
2021-06-24 12:47:02 +00:00
|
|
|
[Original article](https://clickhouse.tech/docs/en/operations/system-tables/merge_tree_settings) <!--hide-->
|