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DM实现类似Oracle绑定执行计划
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DM实现类似Oracle绑定执行计划

XGQ 2022/08/12 2070 0 0

explain select count(1) from xgq a,wj b where a.id=b.id;

SQL> explain select count(1) from xgq a,wj b where a.id=b.id;

1 #NSET2: [41, 1, 8]
2 #PRJT2: [41, 1, 8]; exp_num(1), is_atom(FALSE)
3 #AAGR2: [41, 1, 8]; grp_num(0), sfun_num(1), distinct_flag[0]; slave_empty(0)
4 #HASH2 INNER JOIN: [41, 98009999, 8]; KEY_NUM(1); KEY(A.ID=B.ID) KEY_NULL_EQU(0)
5 #CSCN2: [10, 100000, 4]; INDEX33563654(XGQ as A)
6 #CSCN2: [10, 100000, 4]; INDEX33563665(WJ as B)

explain select /*+ use_nl(a,b) */ count(1) from xgq a,wj b where a.id=b.id;

SQL> explain select /*+ use_nl(a,b) */ count(1) from xgq a,wj b where a.id=b.id;

1 #NSET2: [833061477281, 1, 8]
2 #PRJT2: [833061477281, 1, 8]; exp_num(1), is_atom(FALSE)
3 #AAGR2: [833061477281, 1, 8]; grp_num(0), sfun_num(1), distinct_flag[0]; slave_empty(0)
4 #SLCT2: [833061477281, 98009999, 8]; A.ID = B.ID
5 #NEST LOOP INNER JOIN2: [833061477281, 98009999, 8];
6 #CSCN2: [10, 100000, 4]; INDEX33563654(XGQ as A)
7 #CSCN2: [10, 100000, 4]; INDEX33563665(WJ as B)

sp_set_para_value(1,‘ENABLE_INJECT_HINT’,1);

sf_inject_hint(
‘select count(1) from xgq a,wj b where a.id=b.id’,
‘use_nl(a,b)’,
‘name001’,null,true,true
);

SQL> explain select count(1) from xgq a,wj b where a.id=b.id;

1 #NSET2: [833061477281, 1, 8]
2 #PRJT2: [833061477281, 1, 8]; exp_num(1), is_atom(FALSE)
3 #AAGR2: [833061477281, 1, 8]; grp_num(0), sfun_num(1), distinct_flag[0]; slave_empty(0)
4 #SLCT2: [833061477281, 98009999, 8]; A.ID = B.ID
5 #NEST LOOP INNER JOIN2: [833061477281, 98009999, 8];
6 #CSCN2: [10, 100000, 4]; INDEX33563654(XGQ as A)
7 #CSCN2: [10, 100000, 4]; INDEX33563665(WJ as B)

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