login with theALTER ANY CONNECTIONpermission can use theKILLcommand to end a connection and force a login to reconnect. SQL Server Management Studio can reuse connection information when opening multiple connections to Object Explorer and Query Editor windows. Close all connections to force reconnection...
ALTERTABLEtable_nameADDPRIMARYKEY (column_name); 以下SQL 语句在 employees 表中添加了一个主键: 实例 ALTERTABLEemployees ADDPRIMARYKEY(employee_id); 6. 添加 FOREIGN KEY ALTERTABLEchild_tableADDCONSTRAINTfk_nameFOREIGNKEY (column_name)REFERENCESparent_table (column_name); 以下SQL 语句在 orders 表中添...
ADD COLUMN new_column_name datatype; 以下SQL 语句在 employees 表中添加了一个名为 birth_date 的日期列: 实例 ALTERTABLEemployees ADDCOLUMNbirth_dateDATE; 2. 修改列的数据类型 实例 ALTERTABLETABLE_NAME MODIFYCOLUMNcolumn_name new_datatype; 以下SQL 语句将 employees 表中的 salary 列的数据类型修改为...
<external_access_option>|<FILESTREAM_options>|<HADR_options>|<parameterization_option>|<query_store_options>|<recovery_option>|<service_broker_option>|<snapshot_option>|<sql_option>|<termination>|<temporal_history_retention>|<data_retention_policy>|<compatibility_level>{160|150|140|130|120|110|...
For more information, see Optimize index maintenance to improve query performance and reduce resource consumption.REORGANIZE isn't required in order to move the closed delta rowgroups into compressed rowgroups. The background tuple-mover (TM) process wakes up periodically to compress the closed delta...
For more information, see Optimize index maintenance to improve query performance and reduce resource consumption.REORGANIZE isn't required in order to move the closed delta rowgroups into compressed rowgroups. The background tuple-mover (TM) process wakes up periodically to compress the closed delta...
2、Flink SQL示例 1)、非分区表示例 2)、分区表 五、Flink SQL常见的操作示例 本文简单介绍了DROP、alter、insert和analyze的语法及示例 ,并且将FLink sql常用的sql以java 方法整理成一个类,可以直接在java中使用,或在Flink sql cli中直接使用。 本文依赖flink集群能正常使用。 本文示例java api的实现是通过Flink...
To determine whether a database is in PROTECTED or UNPROTECTED mode, query the STANDBY_DATABASE column of the V$DATABASE dynamic performance view. REGISTER LOGFILE Clause Specify the REGISTER LOGFILE clause from the standby database to register log files from the failed primary. This operation ...
对于数据库级别,使用ALTER DATABASE SCOPED CONFIGURATION (Transact-SQL)中的QUERY_OPTIMIZER_HOTFIXES选项。 在查询级别,通过修改查询使用USE HINT 'ENABLE_QUERY_OPTIMIZER_HOTFIXES'查询提示。 在查询级别,在不更改代码的情况下,使用USE HINT 'ENABLE_QUERY_OPTIMIZER_HOTFIXES'并使用查询存储提示(预览版)功能。
<query_store_options> ::= 适用对象:SQL Server(从 SQL Server 2016 (13.x) 开始) ON | OFF [ ( FORCED ) ] | CLEAR [ ALL ] 控制查询存储是否在此数据库中启用,同时控制是否删除查询存储的内容。 有关详细信息,请参阅 查询存储使用方案。 ON 启用...