这是因为在删除数据时,MySQL 并不会立即将它们清除并整理空间,而是将它们标记为删除,通过 OPTIMIZE TABLE 可以将空间进行整理,减少内存碎片。 InnoDB 引擎并不支持 OPTIMIZE TABLE 操作,它会提示如下信息: OPTIMIZETABLEspecific_table;-- Table does not support optimize, doing recreate + analyze instead 我们可以通...
InnoDBdoes not currently support per-partition optimization;ALTER TABLE ... OPTIMIZE PARTITIONcauses the entire table to rebuilt and analyzed, and an appropriate warning to be issued. (Bug #11751825, Bug #42822) To work around this problem, useALTER TABLE ... REBUILD PARTITIONandALTER TABLE ....
By default, OPTIMIZE TABLE does not work for tables created using any other storage engine and returns a result indicating this lack of support. You can make OPTIMIZE TABLE work for other storage engines by starting mysqld with the --skip-new option. In this case, OPTIMIZE TABLE is just ma...
OPTIMIZE TABLEdoes nothing by default, and returns this message: " The storage engine for the table doesn't support optimize". However, if the server has been started with the--skip-newoption,OPTIMIZE TABLEis linked toALTER TABLE, and recreates the table. This operation frees the unused ...
How Do I Revoke the Permission of a User If grant select on table t1 to public Has Been Executed on a Table An Error Message Is Displayed When a Common User Executes the Statement for Creating or Deleting a GDS or OBS Foreign Table, Indicating that the User Does Not Have the Permission...
By default, OPTIMIZE TABLE does not work for tables created using any other storage engine and returns a result indicating this lack of support. You can make OPTIMIZE TABLE work for other storage engines by starting mysqld with the --skip-new option. In this case, OPTIMIZE TABLE is just ma...
當預測優化被明確啟用或繼承為啟用時,OPTIMIZE和VACUUM將在 Azure Databricks 認為適當的資料表上自動叫用。 如需詳細資訊,請參閱:Unity 目錄受控數據表的預測優化。 範例 如需查看 Delta Lake 新增條件約束和修改資料行的範例,請參閱 Azure Databricks 的條件約束 ...
ALLOW_PAGE_LOCKS = { ON | OFF } 適用於:SQL Server 2008 (10.0.x) 和更新版本 指定是否允許頁面鎖定。 預設值為 ON。 開啟 當存取索引時,允許頁面鎖定。 資料庫引擎會決定使用頁面鎖定的時機。 OFF 不會使用頁面鎖定。 OPTIMIZE_FOR_SEQUENTIAL_KEY = { ON | OFF } 適用於:SQL Server 2019 (15.x)...
By default,OPTIMIZE TABLEdoesnotwork for tables created using any other storage engine and returns a result indicating this lack of support. You can makeOPTIMIZE TABLEwork for other storage engines by startingmysqldwith the--skip-newoption. In this case,OPTIMIZE TABLEis just mapped toALTER TABLE...
Azure SQL Managed Instance does not support memory optimized tables in General Purpose tier. The value ON indicates that the table is memory optimized. Memory-optimized tables are part of the In-Memory OLTP feature, which is used to optimize the performance of transaction processing. To get ...