docs: add parallelism parameter for manual compaction (#2203)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: fengjiachun <3860496+fengjiachun@users.noreply.github.com>
Co-authored-by: jeremyhi <jiachun_feng@proton.me>

Author: Copilot

docs/reference/sql/admin.md

@@ -32,6 +32,15 @@ For example:
 -- Flush the table test --
 admin flush_table("test");
 
--- Schedule a compaction for table test --
+-- Schedule a compaction for table test with default parallelism (1) --
 admin compact_table("test");
+
+-- Schedule a regular compaction with parallelism set to 2 --
+admin compact_table("test", "regular", "parallelism=2");
+
+-- Schedule an SWCS compaction with default time window and parallelism set to 2 --
+admin compact_table("test", "swcs", "parallelism=2");
+
+-- Schedule an SWCS compaction with custom time window and parallelism --
+admin compact_table("test", "swcs", "window=1800,parallelism=2");
 ```

docs/user-guide/deployments-administration/manage-data/compaction.md

@@ -111,7 +111,11 @@ ADMIN COMPACT_TABLE(
 ```
 
 The `<strategy_name>` parameter can be either `twcs` or `swcs` (case insensitive) which refer to Time Windowed Compaction Strategy and Strict Window Compaction Strategy respectively.
-For the `swcs` strategy, the `<strategy_parameters>` specify the window size (in seconds) for splitting SST files. For example:
+For the `swcs` strategy, the `<strategy_parameters>` can specify:
+- The window size (in seconds) for splitting SST files
+- The `parallelism` parameter to control the level of parallelism for compaction (defaults to 1)
+
+For example, to trigger compaction with a 1-hour window:
 
 ```sql
 ADMIN COMPACT_TABLE(
@@ -130,6 +134,23 @@ ADMIN COMPACT_TABLE(
 
 When executing this statement, GreptimeDB will split each SST file into segments with a time span of 1 hour (3600 seconds) and merge these segments into a single output, ensuring no overlapping files remain.
 
+You can also specify the `parallelism` parameter to speed up compaction by processing multiple files concurrently:
+
+```sql
+-- SWCS compaction with default time window and parallelism set to 2
+ADMIN COMPACT_TABLE("monitor", "swcs", "parallelism=2");
+
+-- SWCS compaction with custom time window and parallelism
+ADMIN COMPACT_TABLE("monitor", "swcs", "window=1800,parallelism=2");
+```
+
+The `parallelism` parameter is also available for regular compaction:
+
+```sql
+-- Regular compaction with parallelism set to 2
+ADMIN COMPACT_TABLE("monitor", "regular", "parallelism=2");
+```
+
 The following diagram shows the process of strict window compression:
 
 In Figure A, there are 3 overlapping SST files: `[0, 3]` (which includes timestamps 0, 1, 2, and 3), `[3, 8]`, and `[8, 10]`.

i18n/zh/docusaurus-plugin-content-docs/current/reference/sql/admin.md

@@ -31,6 +31,15 @@ GreptimeDB 提供了一些管理函数来管理数据库和数据：
 -- 刷新表 test --
 admin flush_table("test");
 
--- 为表 test 启动 compaction 任务 --
+-- 为表 test 启动 compaction 任务，默认并行度为 1 --
 admin compact_table("test");
+
+-- 启动常规 compaction，并行度设置为 2 --
+admin compact_table("test", "regular", "parallelism=2");
+
+-- 启动 SWCS compaction，使用默认时间窗口，并行度设置为 2 --
+admin compact_table("test", "swcs", "parallelism=2");
+
+-- 启动 SWCS compaction，自定义时间窗口和并行度 --
+admin compact_table("test", "swcs", "window=1800,parallelism=2");
 ```

i18n/zh/docusaurus-plugin-content-docs/current/user-guide/deployments-administration/manage-data/compaction.md

@@ -108,7 +108,11 @@ ADMIN COMPACT_TABLE(
 ```
 
 `<strategy_name>` 参数可以是 `twcs` 或 `swcs`（大小写不敏感），分别指定时间窗口压缩策略和严格窗口压缩策略。
-对于 `swcs` 策略， `<strategy_parameters>` 指定用于拆分 SST 文件的窗口大小（以秒为单位）。例如：
+对于 `swcs` 策略， `<strategy_parameters>` 可以指定：
+- 用于拆分 SST 文件的窗口大小（以秒为单位）
+- `parallelism` 参数用于控制压缩的并行度（默认为 1）
+
+例如，触发使用 1 小时窗口的压缩：
 
 ```sql
 ADMIN COMPACT_TABLE(
@@ -127,6 +131,23 @@ ADMIN COMPACT_TABLE(
 
 执行此语句时，GreptimeDB 会将每个 SST 文件按 1 小时（3600 秒）的时间跨度拆分成多个分块，并将这些分块合并为一个输出文件，确保没有重叠的文件。
 
+你还可以指定 `parallelism` 参数来通过并发处理多个文件以加速压缩：
+
+```sql
+-- 使用默认时间窗口和并行度为 2 的 SWCS 压缩
+ADMIN COMPACT_TABLE("monitor", "swcs", "parallelism=2");
+
+-- 使用自定义时间窗口和并行度的 SWCS 压缩
+ADMIN COMPACT_TABLE("monitor", "swcs", "window=1800,parallelism=2");
+```
+
+`parallelism` 参数同样适用于常规压缩：
+
+```sql
+-- 并行度为 2 的常规压缩
+ADMIN COMPACT_TABLE("monitor", "regular", "parallelism=2");
+```
+
 下图展示了一次 SWCS 压缩的过程：
 
 在图 A 中，有 3 个重叠的 SST 文件，分别是 `[0, 3]`（也就是包含 0、1、2、3 的时间戳）、`[3, 8]` 和 `[8, 10]`。