1

我刚刚创建了一个包含以下数据的示例表：

CREATE TABLE AAA (  DT DATE   );
insert into aaa (DT) values (to_date('13-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('14-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('15-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('16-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('17-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('18-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('19-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('20-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('21-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('22-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('23-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('24-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('25-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('26-01-2013', 'dd-mm-yyyy'));
insert into aaa (DT) values (to_date('27-01-2013', 'dd-mm-yyyy'));

commit;

然后下面的查询，返回异常结果：（15条记录而不是7条）

select count(*) from aaa d
where 
(d.dt > sysdate)
or
d.dt < to_date(20130120,'yyyymmdd')

但是当我更改“OR”的左侧和右侧时，它会返回正确的结果：（7 条记录）

select count(*) from aaa d
where 
d.dt < to_date(20130120,'yyyymmdd')
or
(d.dt > sysdate)

有人知道这个问题是什么以及如何解决吗？

补充：用d.dt+1替换d.dt也是解决这个问题，

d.dt+1 > sysdate+1
4

1 回答 1

3

好吧，我能够复制它，这种行为背后的原因是 Oracle 对谓词的解释。

可以复制的 OS 和 Oracle 版本：

SQL> host ver

Microsoft Windows [Version 6.1.7601]

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE    11.2.0.1.0      Production
TNS for 64-bit Windows: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production

SQL>

在第一种情况下，谓词被修改为， filter("D"."DT" IS NOT NULL) 而在第二个查询中，谓词按提供的方式工作filter("D"."DT"<TO_DATE(' 2013-01-20 00:00:00', 'syyyy-mm-dd hh24:mi:ss') OR "D"."DT">SYSDATE@!)

SQL> select count(*)
  2  from aaa d
  3  where (d.dt > sysdate)
  4  or d.dt < to_date('20130120','yyyymmdd')
  5  /

  COUNT(*)
----------
        15

Execution Plan
----------------------------------------------------------
Plan hash value: 977873394

---------------------------------------------------------------------------
| Id  | Operation          | Name | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------
|   0 | SELECT STATEMENT   |      |     1 |     9 |     3   (0)| 00:00:01 |
|   1 |  SORT AGGREGATE    |      |     1 |     9 |            |          |
|*  2 |   TABLE ACCESS FULL| AAA  |    15 |   135 |     3   (0)| 00:00:01 |
---------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - filter("D"."DT" IS NOT NULL)

Note
-----
   - dynamic sampling used for this statement (level=2)


Statistics

----------------------------------------------------------
      4  recursive calls
      0  db block gets
     15  consistent gets
      0  physical reads
      0  redo size
    346  bytes sent via SQL*Net to client
    364  bytes received via SQL*Net from client
      2  SQL*Net roundtrips to/from client
      0  sorts (memory)
      0  sorts (disk)
      1  rows processed

SQL> ed
Wrote file afiedt.buf

  1  select count(*)
  2  from aaa d
  3  where d.dt < to_date('20130120','yyyymmdd')
  4* or (d.dt > sysdate)
SQL> 
/

  COUNT(*)
----------
         7

Execution Plan
----------------------------------------------------------
Plan hash value: 977873394

---------------------------------------------------------------------------
| Id  | Operation          | Name | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------
|   0 | SELECT STATEMENT   |      |     1 |     9 |     3   (0)| 00:00:01 |
|   1 |  SORT AGGREGATE    |      |     1 |     9 |            |          |
|*  2 |   TABLE ACCESS FULL| AAA  |     7 |    63 |     3   (0)| 00:00:01 |
---------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - filter("D"."DT"<TO_DATE(' 2013-01-20 00:00:00', 'syyyy-mm-dd
              hh24:mi:ss') OR "D"."DT">SYSDATE@!)

Note
-----
   - dynamic sampling used for this statement (level=2)

Statistics

----------------------------------------------------------
      4  recursive calls
      0  db block gets
     15  consistent gets
      0  physical reads
      0  redo size
    346  bytes sent via SQL*Net to client
    364  bytes received via SQL*Net from client
      2  SQL*Net roundtrips to/from client
      0  sorts (memory)
      0  sorts (disk)
      1  rows processed

SQL>

我无法弄清楚Oracle的这种行为，很可能一些专家可以解释这一点。

同样在第三个示例中，谓词被正确使用。filter("D"."DT"<TO_DATE(' 2013-01-20 00:00:00', 'syyyy-mm-dd hh24:mi:ss') OR INTERNAL_FUNCTION("D"."DT")+1>SYSDATE@!+1)

SQL> ed
Wrote file afiedt.buf

  1  select count(*)
  2  from aaa d
  3  where (d.dt + 1 > sysdate + 1)
  4* or d.dt < to_date('20130120','yyyymmdd')
SQL> /

  COUNT(*)
----------
         7

Execution Plan
----------------------------------------------------------
Plan hash value: 977873394

---------------------------------------------------------------------------
| Id  | Operation          | Name | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------
|   0 | SELECT STATEMENT   |      |     1 |     9 |     3   (0)| 00:00:01 |
|   1 |  SORT AGGREGATE    |      |     1 |     9 |            |          |
|*  2 |   TABLE ACCESS FULL| AAA  |     7 |    63 |     3   (0)| 00:00:01 |
---------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - filter("D"."DT"<TO_DATE(' 2013-01-20 00:00:00', 'syyyy-mm-dd
              hh24:mi:ss') OR INTERNAL_FUNCTION("D"."DT")+1>SYSDATE@!+1)

Note
-----
   - dynamic sampling used for this statement (level=2)


Statistics
----------------------------------------------------------
          5  recursive calls
          0  db block gets
         15  consistent gets
          0  physical reads
          0  redo size
        346  bytes sent via SQL*Net to client
        364  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
          1  rows processed

SQL>

很明显，不能从 Linux 服务器上的 Oracle 版本 11.2.0.2.0 和 11.2.0.3.0 复制相同的内容。

更新：

正如Alex Poole在评论中提到的那样 - “这可能是错误 9495697，'对于在同一列上包含两个 OR'd 过滤谓词的查询可能会返回错误的结果，其中一个谓词的另一侧不是编译时常量（例如。它是一个绑定、sysdate 等。）”

于 2014-01-12T17:00:38.277 回答