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  1. MariaDB Server
  2. MDEV-767

LP:1002139 - Unsorted result for query with ORDER BY if ref_or_null access is used

        Details

        • Type: Bug
        • Status: Closed
        • Priority: Major
        • Resolution: Won't Fix
        • Affects Version/s: 5.2.15
        • Fix Version/s: None
        • Component/s: None
        • Labels:

          Description

          The following sequence of commands produces unsorted result in MariaDB 5.2 though sorting is asked for:

          CREATE TABLE t1 (
  a INT,
  c INT,
  UNIQUE KEY a_c (a,c),
  KEY (a)) engine=myisam;

INSERT INTO t1 VALUES (1,10), (2,NULL), (2,10);
ANALYZE TABLE t1;
EXPLAIN
SELECT c FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
SELECT c FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;

MariaDB [test]> SELECT c FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
+------+
| c    |
+------+
|   10 |
| NULL |
+------+

          In MariaDB the test case works correctly.

          See also bug #13531865 from mysql-trunk code line.

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                sanja Oleksandr Byelkin added a comment -

                Re: Unsorted result for query with ORDER BY if ref_or_null access is used
                It is 5.2 only bug.

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                sanja Oleksandr Byelkin added a comment - Re: Unsorted result for query with ORDER BY if ref_or_null access is used It is 5.2 only bug.
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                ratzpo Rasmus Johansson added a comment -

                Launchpad bug id: 1002139

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                ratzpo Rasmus Johansson added a comment - Launchpad bug id: 1002139
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                sanja Oleksandr Byelkin added a comment -

                It is fixed in 5.3 and above.

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                sanja Oleksandr Byelkin added a comment - It is fixed in 5.3 and above.
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                sanja Oleksandr Byelkin added a comment -

                Fix to above comment: It is not reproducable on 5.3, 5.5 and 10.0 (10.0-base).

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                sanja Oleksandr Byelkin added a comment - Fix to above comment: It is not reproducable on 5.3, 5.5 and 10.0 (10.0-base).

                  People

                  • Assignee:
                    sanja Oleksandr Byelkin
                    Reporter:
                    igor Igor Babaev
                  • Votes:
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                    Watchers:
                    2 Start watching this issue

                    Dates

                    • Created:
                      Updated:
                      Resolved: