参考:https://stackoverflow.com/questions/42481826/how-to-use-multiple-where-clause-in-one-sql-query
Extra中Using Index与Using Where,MySQL官方文档的解释如下:Using IndexThe column information is retrieved from the table using only information in the index tree without having to do an additional seek to read the actual row. This strategy can be used when the query uses only columns that are par...
解决方法:使用Query洞察排查当前Query是否在同一时间执行了TRUNCATE或DROP操作,详情请参见Query洞察。 ERRCODE_FEATURE_NOT_SUPPORTED或者Unsupported Feature 报错:Feature not supported: insert into parent table 问题原因:不支持直接写入数据至分区父表。 解决方法:SQL方式执行INSERT时,需要将数据写入指定的分区子表。详情...
The hint only affects the views in the statements' SELECT part, including those views in INSERT, UPDATE, MERGE, and DELETE statements. FAST integer_value Specifies that the query is optimized for fast retrieval of the first integer_value number of rows. This result is a non-negati...
For example, the following statements are not allowed: ALTER TABLE t1 DROP COLUMN f1 DROP (f2); ALTER TABLE t1 DROP COLUMN f1 SET UNUSED (f2); ALTER TABLE t1 DROP (f1) ADD (f2 NUMBER); ALTER TABLE t1 SET UNUSED (f3) ADD (CONSTRAINT ck1 CHECK (f2 > 0)); You can drop an ...
A SQL select statement has two to three clauses. The SELECT clause tells the database where to look for the data and asks it to return a specific result. Note:SELECT statements always end with a semi-colon (;) either at the end of the last clause or on a line by its...
SET @DSQL = 'SELECT F1 FROM Evaluation.CalculatedLimits_' + CAST(@PlantLineMapId as varchar) + ' WHERE PROCESS = 2 AND TIMESTAMP = ' + '''+CONVERT(nvarchar(50), @TempStartDate,121)+''' SET @RowNo = @RowNo + 1 END SET
Multiple Active Result Sets (MARS) 支援列存儲索引。 全新動態管理檢視sys.dm_db_column_store_row_group_physical_stats (Transact-SQL)提供資料列群組層級的效能疑難排解資訊。 數據行存放區索引上的所有查詢都可以在批次模式中執行。 先前,只有平行查詢可以在批次模式中執行。
SELECTname, compatibility_levelFROMsys.databasesWHEREname= db_name(); GO The following query ignores theSET LANGUAGEstatement except under compatibility level 120 or higher. SQL SETDATEFORMAT dmy;DECLARE@t2ASDATE='12/5/2011';SETLANGUAGEdutch;SELECTCONVERT(VARCHAR(11), @t2...
You cannot query or perform DML statements on the storage table directly, but you can modify the nested table column storage characteristics by using the name of storage table in an ALTER TABLE statement. See Also: ALTER TABLE for information about modifying nested table column storage character...