Oracle索引分析与比较
SQL> select 'number',dump(1,16) from dual 2 union all select 'number',dump(2,16) from dual3 union all select 'number',dump(3,16) from dual;
'NUMBE DUMP(1,16)
------ -----------------
number Typ=2 Len=2: c1,2 (1)
number Typ=2 Len=2: c1,3 (2)
number Typ=2 Len=2: c1,4 (3)
再对比一下反向以后的情况:
SQL> select 'number',dump(reverse(1),16) from dual
2 union all select 'number',dump(reverse(2),16) from dual
3 union all select 'number',dump(reverse(3),16) from dual;
'NUMBE DUMP(REVERSE(1),1
------ -----------------
number Typ=2 Len=2: 2,c1 (1)
number Typ=2 Len=2: 3,c1 (2)
number Typ=2 Len=2: 4,c1 (3)
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