已用时间: 00: 00: 00.04Execution Plan
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0 SELECT STATEMENT Optimizer=CHOOSE
1 0 SORT (ORDER BY)
2 1 TABLE ACCESS (BY INDEX ROWID) OF 'PCS_JY'
3 2 NESTED LOOPS
4 3 NESTED LOOPS
5 4 TABLE ACCESS (BY INDEX ROWID) OF 'ZH_USER'
6 5 INDEX (RANGE SCAN) OF 'IDX_CREATROLE' (NON-UNIQUE)
7 4 TABLE ACCESS (BY INDEX ROWID) OF 'ZH_POPEDOM_USER'
8 7 INDEX (RANGE SCAN) OF 'IDX_ZH_POPEDOM_USER' (NON-UNIQUE)
9 3 INDEX (RANGE SCAN) OF 'IDX_PCS_JY' (NON-UNIQUE)上面是我的执行计划,
请问最先访问的是哪个表?
我理解的是先访问表'ZH_USER',
再访问表'ZH_POPEDOM_USER',
最后访问表'PCS_JY'。
不知道理解的对不对,
请指点。
----------------------------------------------------------
0 SELECT STATEMENT Optimizer=CHOOSE
1 0 SORT (ORDER BY)
2 1 TABLE ACCESS (BY INDEX ROWID) OF 'PCS_JY'
3 2 NESTED LOOPS
4 3 NESTED LOOPS
5 4 TABLE ACCESS (BY INDEX ROWID) OF 'ZH_USER'
6 5 INDEX (RANGE SCAN) OF 'IDX_CREATROLE' (NON-UNIQUE)
7 4 TABLE ACCESS (BY INDEX ROWID) OF 'ZH_POPEDOM_USER'
8 7 INDEX (RANGE SCAN) OF 'IDX_ZH_POPEDOM_USER' (NON-UNIQUE)
9 3 INDEX (RANGE SCAN) OF 'IDX_PCS_JY' (NON-UNIQUE)上面是我的执行计划,
请问最先访问的是哪个表?
我理解的是先访问表'ZH_USER',
再访问表'ZH_POPEDOM_USER',
最后访问表'PCS_JY'。
不知道理解的对不对,
请指点。
'PCS_JY'