results." a.k.a. "Proper cleanup of subqueries is missing for SET and DO
statements". (Version #2 with after-review fixes).
To perform proper cleanup for statements that can contain subqueries
but don't have main select we must call free_undelaid_joins().
FOUND is not a reserved keyword anymore
Added Item_field::set_no_const_sub() to be able to mark fields that can't be substituted
Added 'simple_select' method to be able to quickly determinate if a select_result is a normal SELECT
Note that the 5.0 tree is not yet up to date: Sanja will have to fix multi-update-locks for this merge to be complete
improved mechanisn of detection posibility to be NULL for single row queries
switched off substitution optimisation for single row subqueries in PS due to problem in resolving substituted expressions
(changes to make subselects test working with PS protocol)
prepared statements when LIMIT is used" and post-review comments.
The fix changes the approach we calculate the need for ORDER BY
in UNION: the previous was not PS friendly, as it damaged SELECT_LEX
options in case of single select.
Added the code processing on expressions for applying
multiple equalities.
sql_select.cc:
Post-merge fixes for Item_equal patch.
Added the code processing on expressions for applying
multiple equalities.
Many files:
Post-merge fixes for Item_equal patch.
item_cmpfunc.cc:
Post-merge fixes for Item_equal patch.
Fixed a problem when an equality field=const cannot be applied to
the predicate P(field,c) for constant propagation as a conversion
of field is needed.
item.h, item.cc:
Fixed a problem when an equality field=const cannot be applied to
the predicate P(field,c) for constant propagation as a conversion
of field is needed.
We have next problem here:
active_index is wrong in the subselect's handler on the second val_int() call.
Optimizer sees that we can use index-read for that kind of condition,
and matching_cond() (sql/opt_sum.cc) doesn't. I suspect, proper solution is
to add appropriate code to the matching_cond() but now just added
missed initialization.
