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| author | kaa@polly.(none) <> | 2007-10-17 20:08:58 +0400 |
|---|---|---|
| committer | kaa@polly.(none) <> | 2007-10-17 20:08:58 +0400 |
| commit | 6d1f3e8de56e3cc861272265fc1f6119a41036a9 (patch) | |
| tree | df4dfded543b3b043c0b27d956a2b0bab863da1b /libmysql | |
| parent | 80a2d47b22dde619656b55831f2a920bfcf8b5b1 (diff) | |
| download | mariadb-git-6d1f3e8de56e3cc861272265fc1f6119a41036a9.tar.gz | |
Fix for bug #31207: Test "join_nested" shows different strategy on IA64
CPUs / Intel's ICC compile
The bug is a combination of two problems:
1. IA64/ICC MySQL binaries use glibc's qsort(), not the one in mysys.
2. The order relation implemented by join_tab_cmp() is not transitive,
i.e. it is possible to choose such a, b and c that (a < b) && (b < c)
but (c < a). This implies that result of a sort using the relation
implemented by join_tab_cmp() depends on the order in which
elements are compared, i.e. the result is implementation-specific. Since
choose_plan() uses qsort() to pre-sort the
join tables using join_tab_cmp() as a compare function, the results of
the sorting may vary depending on qsort() implementation.
It is neither possible nor important to implement a better ordering
algorithm in join_tab_cmp(). Therefore the only way to fix it is to
force our own qsort() to be used by renaming it to my_qsort(), so we don't depend
on linker to decide that.
This patch also "fixes" bug #20530: qsort redefinition violates the
standard.
Diffstat (limited to 'libmysql')
| -rw-r--r-- | libmysql/Makefile.shared | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/libmysql/Makefile.shared b/libmysql/Makefile.shared index dc6d658fcdf..5947ae26486 100644 --- a/libmysql/Makefile.shared +++ b/libmysql/Makefile.shared @@ -73,7 +73,7 @@ sqlobjects = net.lo sql_cmn_objects = pack.lo client.lo my_time.lo # Not needed in the minimum library -mysysobjects2 = my_lib.lo +mysysobjects2 = my_lib.lo mf_qsort.lo mysysobjects = $(mysysobjects1) $(mysysobjects2) target_libadd = $(mysysobjects) $(mystringsobjects) $(dbugobjects) \ $(sql_cmn_objects) $(vio_objects) $(sqlobjects) |