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BUG#32198: Comparison of DATE with DATETIME still not using indexes correctly

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- Make conditions like "date_col $CMP$ 'datetime-const'" range-sargable
This commit is contained in:
sergefp@mysql.com
2007-12-13 13:38:22 +03:00
parent 55d6d04df0
commit dd0854db54
4 changed files with 67 additions and 1 deletions
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27
sql/opt_range.cc
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@ -4414,6 +4414,7 @@ get_mm_leaf(PARAM *param, COND *conf_func, Field *field, KEY_PART *key_part,
{
tree= new (alloc) SEL_ARG(field, 0, 0);
tree->type= SEL_ARG::IMPOSSIBLE;
goto end;
}
else
{
@ -4422,8 +4423,32 @@ get_mm_leaf(PARAM *param, COND *conf_func, Field *field, KEY_PART *key_part,
for the cases like int_field > 999999999999999999999999 as well.
*/
tree= 0;
if (err == 3 && field->type() == FIELD_TYPE_DATE &&
(type == Item_func::GT_FUNC || type == Item_func::GE_FUNC ||
type == Item_func::LT_FUNC || type == Item_func::LE_FUNC) )
{
/*
We were saving DATETIME into a DATE column, the conversion went ok
but a non-zero time part was cut off.
In MySQL's SQL dialect, DATE and DATETIME are compared as datetime
values. Index over a DATE column uses DATE comparison. Changing
from one comparison to the other is possible:
datetime(date_col)< '2007-12-10 12:34:55' -> date_col<='2007-12-10'
datetime(date_col)<='2007-12-10 12:34:55' -> date_col<='2007-12-10'
datetime(date_col)> '2007-12-10 12:34:55' -> date_col>='2007-12-10'
datetime(date_col)>='2007-12-10 12:34:55' -> date_col>='2007-12-10'
but we'll need to convert '>' to '>=' and '<' to '<='. This will
be done together with other types at the end of this function
(grep for field_is_equal_to_item)
*/
}
else
goto end;
}
goto end;
}
if (err < 0)
{