5 SORT (AGGREGATE) (COST=,CARD=1,BYTES=21)
4 NESTED LOOPS (COST=108968,CARD=1213745,BYTES=25488645)
1 TABLE ACCESS (FULL) OF 'SWORD.SUPER_USER' (COST=2,CARD=2794,BYTES=27940)
3 TABLE ACCESS (BY INDEX ROWID) OF 'SWORD.SWD_BILLDETAIL' (COST=39,CARD=54863946,BYTES=603503406)
2 INDEX (RANGE SCAN) OF 'SWORD.IDX_DETAIL_CN' (NON-UNIQUE) (COST=3,CARD=54863946,BYTES=)
这个查询耗费的时间很长，需要1个多小时。
运行后的信息如下：
COUNT(A.CHANNELB.USER_CLASS)
------------------------------
1186387
Elapsed: 01:107:6429.87
Execution Plan
----------------------------------------------------------
0 SELECT STATEMENT Optimizer=CHOOSE (Cost=108968 Card=1 Bytes=21)
1 0 SORT (AGGREGATE)
2 1 NESTED LOOPS (Cost=108968 Card=1213745 Bytes=25488645)
3 2 TABLE ACCESS (FULL) OF 'SUPER_USER' (Cost=2 Card=2794Bytes=27940)
4 2 TABLE ACCESS (BY INDEX ROWID) OF 'SWD_BILLDETAIL' (Cost=39 Card=54863946 Bytes=603503406)
5 4 INDEX (RANGE SCAN) OF 'IDX_DETAIL_CN' (NON-UNIQUE) (Cost=3 Card=54863946)
Statistics
----------------------------------------------------------
0 recursive calls
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