database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

MDEV-6950 Bad results with joins comparing DATE/DATETIME and INT/DECIMAL/DOUBLE/ENUM/VARCHAR columns

Browse Source 
MDEV-6971 Bad results with joins comparing TIME and DOUBLE/DECIMAL columns
Disallow using indexes on non-temporal columns to optimize
ref access, range access and table elimination when the counterpart's
cmp_type is TIME_RESULT, e.g.:
  SELECT * FROM t1 WHERE indexed_int_column=time_expression;
Only index on a temporal column can be used to optimize temporal comparison
operations.
This commit is contained in:
Alexander Barkov
2014-11-18 16:33:29 +04:00
parent 807934d083
commit e52b1637e0
15 changed files with 505 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
sql/sql_select.cc
View File

@ -4440,6 +4440,10 @@ add_key_field(JOIN *join,
if (!eq_func) // eq_func is NEVER true when num_values > 1
return;
if ((*value)->cmp_type() == TIME_RESULT &&
field->cmp_type() != TIME_RESULT)
return;
/*
We can't use indexes when comparing a string index to a
number or two strings if the effective collation