5 SORT (AGGREGATE) (COST=,CARD=1,BYTES=21)
4 NESTED LOOPS (COST=109893304,CARD=1213745,BYTES=25488645)
1 TABLE ACCESS (FULL) OF 'SWORD.SWD_BILLDETAIL' (COST=165412,CARD=54863946,BYTES=603503406)
3 TABLE ACCESS (BY INDEX ROWID) OF 'SWORD.SUPER_USER' (COST=2,CARD=2794,BYTES=27940)
2 INDEX (RANGE SCAN) OF 'SWORD.IDX_SUPER_USER_CN' (NON-UNIQUE) (COST=1,CARD=2794,BYTES=)
这个查询耗费的时间较短，才20分钟，性能比较好。运行后的信息如下：
COUNT(A.CHANNELB.USER_CLASS)
------------------------------
1186387
Elapsed: 00:20:1208.87
Execution Plan
----------------------------------------------------------
0 SELECT STATEMENT Optimizer=CHOOSE (Cost=109893304 Card=1 Bytes=21)
1 0 SORT (AGGREGATE)
2 1 NESTED LOOPS (Cost=109893304 Card=1213745 Bytes=25488645)
3 2 TABLE ACCESS (FULL) OF 'SWD_BILLDETAIL' (Cost=165412 Card=54863946 Bytes=603503406)
4 2 TABLE ACCESS (BY INDEX ROWID) OF 'SUPER_USER' (Cost=2Card=2794 Bytes=27940)
5 4 INDEX (RANGE SCAN) OF 'IDX_SUPER_USER_CN' (NON-UNIQUE) (Cost=1 Card=2794)
Statistics
----------------------------------------------------------
0 recursive calls
8823 db block gets
56650250 consistent gets
1413250 physical reads
0 redo size
316 bytes sent via SQL*Net to client
421 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
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