手工收集统计信息

news2025/7/14 15:42:27

有时想对某些表收集统计信息

CREATE OR REPLACE PROCEDURE GATHER_STATS
AS
    DECLARE
        V_SQL1 VARCHAR(1000);
        --表游标
        CURSOR C1 IS
            SELECT (SELECT USER) AS TABLE_OWNER,
                   TABLE_NAME
              FROM USER_TABLES;  --可以在这里加过滤条件
        
        --索引游标
        CURSOR C2 IS
            SELECT TABLE_OWNER,
                   INDEX_NAME
              FROM USER_INDEXES
             WHERE TABLE_OWNER IN (select USER);
    
    BEGIN
        --收集表统计信息
        FOR C IN C1
        LOOP
            V_SQL1 :='DBMS_STATS.GATHER_TABLE_STATS('''||C.TABLE_OWNER||''','''||C.TABLE_NAME||''',NULL,100,FALSE,''FOR ALL COLUMNS SIZE AUTO'',8,''AUTO'',FALSE);';
            EXECUTE IMMEDIATE V_SQL1;
        END LOOP;
		
        --收集索引统计信息
        FOR C IN C2
        LOOP
            V_SQL1 :='DBMS_STATS.GATHER_INDEX_STATS('''||C.TABLE_OWNER||''','''||C.INDEX_NAME||''',NULL,100,NULL,NULL,8);';
            EXECUTE IMMEDIATE V_SQL1;
        END LOOP;
    END;
/

执行方法：
在这里插入图片描述
表小就很快，表大就慢

看各用户占用空间

select username,round(user_used_space(username) * (select PARA_VALUE   FROM v$dm_ini where para_name ='GLOBAL_PAGE_SIZE')/1024/1024) USED_MB FROM dba_users;

在这里插入图片描述
收集统计信息的速度是 1分钟1G。

观察进展

SELECT TOP 10 AO.OWNER, SO.NAME AS "OBJECT_NAME", MAX(ST.LAST_GATHERED) AS "LAST_ANALYZED" 
    FROM SYSSTATS ST,
         SYSOBJECTS SO,
         ALL_OBJECTS AO
   WHERE ST.ID=AO.OBJECT_ID
     AND SO.ID=AO.OBJECT_ID
     --AND AO.OWNER=(select user)
GROUP BY AO.OWNER, SO.NAME
ORDER BY 3 DESC;