2022-08-26 19:07:59 +00:00
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---
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slug: /zh/operations/system-tables/merge_tree_settings
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---
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2021-12-17 02:25:08 +00:00
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# system.merge_tree_settings {#system-merge_tree_settings}
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2020-06-22 08:45:22 +00:00
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2021-12-18 12:41:09 +00:00
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包含 `MergeTree` 表的设置 (Setting) 信息。
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2020-06-22 08:45:22 +00:00
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列:
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2021-12-18 12:41:09 +00:00
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- `name` (String) — 设置名称。
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- `value` (String) — 设置的值。
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- `description` (String) — 设置描述。
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- `type` (String) — 设置类型 (执行特定的字符串值)。
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- `changed` (UInt8) — 该设置是否在配置中明确定义或是明确改变。
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2021-12-17 01:45:04 +00:00
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**示例**
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```sql
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:) SELECT * FROM system.merge_tree_settings LIMIT 4 FORMAT Vertical;
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```
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```text
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Row 1:
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──────
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name: index_granularity
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value: 8192
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changed: 0
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description: How many rows correspond to one primary key value.
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type: SettingUInt64
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Row 2:
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──────
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name: min_bytes_for_wide_part
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value: 0
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changed: 0
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description: Minimal uncompressed size in bytes to create part in wide format instead of compact
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type: SettingUInt64
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Row 3:
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──────
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name: min_rows_for_wide_part
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value: 0
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changed: 0
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description: Minimal number of rows to create part in wide format instead of compact
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type: SettingUInt64
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Row 4:
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──────
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name: merge_max_block_size
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value: 8192
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changed: 0
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description: How many rows in blocks should be formed for merge operations.
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type: SettingUInt64
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4 rows in set. Elapsed: 0.001 sec.
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```
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[原文](https://clickhouse.com/docs/zh/operations/system-tables/merge_tree_settings) <!--hide-->
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