declare type row_num_type is table of number index by simple_integer; type row_text_type is table of varchar2(10) index by simple_integer; row_num_tab row_num_type; row_text_tab row_text_type; v_total number; sql_stmt varchar2(300);begin for i in 1..10 loop row_num_tab(i) ...
除了游标,SQL Server还提供了WHILE循环来实现遍历操作。通过使用一个条件表达式,WHILE循环可以反复执行一段代码,直到条件不满足为止。 下面是一个使用WHILE循环遍历表数据的示例: DECLARE@emp_idINT;DECLARE@emp_nameVARCHAR(50);DECLARE@counterINT=1;WHILE@counter<=(SELECTCOUNT(*)FROMemployees)BEGINSELECT@emp_id=...
这将取代while循环。 UPDATE [supdata] SET [Scheduled_Open] = [cd].[Scheduled_Open_Sum] FROM [#SupplementalData1] [supdata] CROSS APPLY ( SELECT COUNT([CNTNR_NAME]) AS [Scheduled_Open_Sum] FROM [#data] [c] WHERE [c].[NEED_DATE] >= [supdata].[RPTNG_Week] AND [c].[LOB_CODE...
Can we optimise While Loop in sql server for large number of data? Can we pass parameters to the trigger?(Beginner) Can we RAISERROR inside MERGE Statement Can we select Bottom 1000 rows of a database Table from SSMS 2008 R2? Can we set value in a variable inside a select statement ca...
Bulk update (BU) locks allow multiple threads to bulk load data concurrently into the same table, while preventing other processes that aren't bulk loading data from accessing the table.The behavior is similar to when the user explicitly specifies TABLOCK hint while performing bulk load, or ...
mysql:ytt>desc selectcount(*)from t1 a join t1 b on a.r1=b.r1\G***1.row***id:1select_type:SIMPLEtable:apartitions:NULLtype:indexpossible_keys:idx_r1key:idx_r1key_len:5ref:NULLrows:2552706filtered:100.00Extra:Usingwhere;Using index***2.row***id:1select_type:SIMPLEtable:bpartitions...
'DISABLE_OPTIMIZED_NESTED_LOOP' 指示查詢處理器在產生查詢計劃時,不要針對優化的巢狀循環聯結使用排序作業(批次排序)。 此提示名稱相當於 追蹤旗標 2340。 此提示也適用於明確的排序和批次排序。 'DISABLE_OPTIMIZER_ROWGOAL' 導致SQL Server 產生計劃,其不會對包含這些關鍵詞的查詢使用數據列目標修改:- TOP- OPT...
WHILE TRUE LOOP INSERT INTO target_table (column1, column2) SELECT column1, column2FROMsource_table LIMIT batch_size OFFSET offset; IF NOT FOUND THEN EXIT; END IF; COMMIT; -- 每批提交一次事务 offset := offset + batch_size; END LOOP; ...
使用HASH JOIN代替NESTED LOOP 配置enable_batched_mode=true减少网络往返 2.2 数据倾斜处理 sql -- 自定义哈希分区解决热点 ALTERTABLEsales_data REPARTITION BY HASH(product_id) PARTITIONS32; 三、高性能执行策略 3.1 批处理与流式处理 java // Java批处理示例(每批5000条) ...
For more information, see Business continuity and database recovery and Drive business continuity with SQL Server (e-book). Backup while in use SQL Server uses an online backup process that can occur while the database is running. You can do a full backup, a partial back...