更新时间:2024-04-18 GMT+08:00
ANALYZE
Teradata的SELECT命令(缩写关键字为SEL)用于指定从哪一列中检索数据。
在GaussDB(DWS)中使用ANALYZE来收集优化器统计信息,这些统计信息将用于查询性能。
输入:ANALYZE,使用INSERT
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INSERT INTO employee(empno,ename) Values (1,'John'); COLLECT STAT on employee; |
输出
1 2 3 |
INSERT INTO employee( empno, ename) SELECT 1 ,'John'; ANALYZE employee; |
输入:ANALYZE,使用UPDATE
1 2 3 |
UPD employee SET ename = 'Jane' WHERE ename = 'John'; COLLECT STAT on employee; |
输出
1 2 3 |
UPDATE employee SET ename = 'Jane' WHERE ename = 'John'; ANALYZE employee; |
输入:ANALYZE,使用DELETE
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DEL FROM employee WHERE ID > 10; COLLECT STAT on employee; |
输出
1 2 |
DELETE FROM employee WHERE ID > 10; ANALYZE employee; |
父主题: SELECT