[opt](config) rename alter_inverted_index_worker_count to alter_index_worker_count, and add docs (#21985)

be/src/agent/task_worker_pool.cpp

@@ -157,7 +157,7 @@ void TaskWorkerPool::start() {
     case TaskWorkerType::ALTER_TABLE:
         break;
     case TaskWorkerType::ALTER_INVERTED_INDEX:
-        _worker_count = config::alter_inverted_index_worker_count;
+        _worker_count = config::alter_index_worker_count;
         _cb = std::bind<void>(&TaskWorkerPool::_alter_inverted_index_worker_thread_callback, this);
         break;
     case TaskWorkerType::CLONE:

be/src/common/config.cpp

@@ -159,8 +159,8 @@ DEFINE_Int32(clear_transaction_task_worker_count, "1");
 DEFINE_Int32(delete_worker_count, "3");
 // the count of thread to alter table
 DEFINE_Int32(alter_tablet_worker_count, "3");
-// the count of thread to alter inverted index
-DEFINE_Int32(alter_inverted_index_worker_count, "3");
+// the count of thread to alter index
+DEFINE_Int32(alter_index_worker_count, "3");
 // the count of thread to clone
 DEFINE_Int32(clone_worker_count, "3");
 // the count of thread to clone

be/src/common/config.h

@@ -201,8 +201,8 @@ DECLARE_Int32(clear_transaction_task_worker_count);
 DECLARE_Int32(delete_worker_count);
 // the count of thread to alter table
 DECLARE_Int32(alter_tablet_worker_count);
-// the count of thread to alter inverted index
-DECLARE_Int32(alter_inverted_index_worker_count);
+// the count of thread to alter index
+DECLARE_Int32(alter_index_worker_count);
 // the count of thread to clone
 DECLARE_Int32(clone_worker_count);
 // the count of thread to clone

docs/en/docs/admin-manual/config/be-config.md

@@ -1285,6 +1285,11 @@ BaseCompaction:546859:
 * Description: The number of threads making schema changes
 * Default value: 3
 
+### `alter_index_worker_count`
+
+* Description: The number of threads making index change
+* Default value: 3
+
 #### `ignore_load_tablet_failure`
 
 * Type: bool

docs/en/docs/advanced/alter-table/schema-change.md

@@ -280,6 +280,7 @@ SHOW ALTER TABLE COLUMN\G;
 * `alter_tablet_worker_count`: Number of threads used to perform historical data conversion on the BE side. The default is 3. If you want to speed up the Schema Change job, you can increase this parameter appropriately and restart the BE. But too many conversion threads can cause increased IO pressure and affect other operations. This thread is shared with the Rollup job.
 
 
+* `alter_index_worker_count`: Number of threads used to perform historical data build index on the BE size (note: only inverted index is supported now). The default is 3. If you want to speed up the Index Change job, you can increase this parameter appropriately and restart the BE. But too many threads can cause increased IO pressure and affect other operations.
 
 ## More Help
 

docs/zh-CN/docs/admin-manual/config/be-config.md

@@ -1301,6 +1301,11 @@ BaseCompaction:546859:
 * 描述：进行schema change的线程数
 * 默认值：3
 
+### `alter_index_worker_count`
+
+* 描述：进行index change的线程数
+* 默认值：3
+
 #### `ignore_load_tablet_failure`
 
 * 类型：bool

docs/zh-CN/docs/advanced/alter-table/schema-change.md

@@ -289,6 +289,8 @@ SHOW ALTER TABLE COLUMN\G;
 
 - `alter_tablet_worker_count`：在 BE 端用于执行历史数据转换的线程数。默认为 3。如果希望加快 Schema Change 作业的速度，可以适当调大这个参数后重启 BE。但过多的转换线程可能会导致 IO 压力增加，影响其他操作。该线程和 Rollup 作业共用。
 
+- `alter_index_worker_count`：在 BE 端用于执行历史数据构建索引的线程数（注：当前只支持倒排索引）。默认为 3。如果希望加快 Index Change 作业的速度，可以适当调大这个参数后重启 BE。但过多的线程可能会导致 IO 压力增加，影响其他操作。
+
 ## 更多帮助
 
 关于Schema Change使用的更多详细语法及最佳实践，请参阅 [ALTER TABLE COLUMN](../../sql-manual/sql-reference/Data-Definition-Statements/Alter/ALTER-TABLE-COLUMN.md) 命令手册，你也可以在 MySql 客户端命令行下输入 `HELP ALTER TABLE COLUMN`  获取更多帮助信息。