Bug #9912 Different (but equivalent) index chosen in strategy
Submitted: 14 Apr 2005 16:38 Modified: 21 Apr 2005 10:43
Reporter: Joerg Bruehe Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server Severity:S3 (Non-critical)
Version:5.0.4 OS:Solaris (Solaris 8 / i386)
Assigned to: Sergey Petrunya CPU Architecture:Any

[14 Apr 2005 16:38] Joerg Bruehe
Description:
Release build of 5.0.4, based on ChangeSet
  1.1893 05/04/13 13:17:39 mskold@mysql.com +1 -0
  Fixed failed merge

This is the first working build on this platform, AFAIK. We previously used "gcc" and had a failing lib dependency, now we use Sun Studio compilers.

Test failure:
-------------------------------------------------------
*** r/index_merge_ror.result    Wed Apr 13 17:24:32 2005
--- r/index_merge_ror.reject    Thu Apr 14 11:58:36 2005
***************
*** 182,188 ****
  4
  explain select count(a) from t2 where a='AAAAAAAA' and b='AAAAAAAA';
  id    select_type     table   type    possible_keys   key     key_len ref     rows    Extra
! 1     SIMPLE  t2      ref     a,b     a       6       const   4       Using where
  select count(a) from t2 where a='AAAAAAAA' and b='AAAAAAAA';
  count(a)
  4
--- 182,188 ----
  4
  explain select count(a) from t2 where a='AAAAAAAA' and b='AAAAAAAA';
  id    select_type     table   type    possible_keys   key     key_len ref     rows    Extra
! 1     SIMPLE  t2      ref     a,b     b       6       const   4       Using where
  select count(a) from t2 where a='AAAAAAAA' and b='AAAAAAAA';
  count(a)
  4
-------------------------------------------------------

I understand the test to treat columns 'a' and 'b' equal, same type, same data contents, so they should be equivalent in the search strategy. Still this is a test failure we should get rid of.

How to repeat:
Build + test.
[21 Apr 2005 9:28] Bugs System
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/24190