ClickHouse/docs/zh/operations/system-tables/merge_tree_settings.md
2022-08-26 15:07:59 -04:00

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---
slug: /zh/operations/system-tables/merge_tree_settings
---
# system.merge_tree_settings {#system-merge_tree_settings}
包含 `MergeTree` 表的设置 (Setting) 信息。
列:
- `name` (String) — 设置名称。
- `value` (String) — 设置的值。
- `description` (String) — 设置描述。
- `type` (String) — 设置类型 (执行特定的字符串值)。
- `changed` (UInt8) — 该设置是否在配置中明确定义或是明确改变。
**示例**
```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.
```
[原文](https://clickhouse.com/docs/zh/operations/system-tables/merge_tree_settings) <!--hide-->