NOT NULL NUMBER(38)
VC2PRIZEFLAG VARCHAR2(1)
VC2DESC VARCHAR2(1000)
6.决定创建新的索引以消除全表扫描
SQL> create index hs_info_NUMCATALOGGUID on hs_info(NUMCATALOGGUID);
Index created.
SQL> set autotrace trace explain
SQL> select i.vc2title,i.numinfoguid
2 from hs_info i where i.intenabledflag = 1
3 and i.intpublishstate = 1 and i.datpublishdate <=sysdate
4 and i.numcatalogguid = 3475
5 order by i.datpublishdate desc, i.numorder desc ;
Execution Plan
----------------------------------------------------------
0 SELECT STATEMENT Optimizer=CHOOSE (Cost=12 Card=1 Bytes=106)
1 0 SORT (ORDER BY) (Cost=12 Card=1 Bytes=106)
2 1 TABLE ACCESS (BY INDEX ROWID) OF ''''HS_INFO'''' (Cost=2 Card=1 Bytes=106)
3 2 INDEX (RANGE SCAN) OF ''''HS_INFO_NUMCATALOGGUID'''' (NON-UNIQUE) (Cost=1 Card=1)