This bug was introduced when the patch resolving the
performance problem 17164 was applied. As a result
of that modification the not_null_tables attributes
were calculated incorrectly for constant OR conditions.
This triggered invalid conversion of outer joins into
inner joins.
The convert_constant_item() function converts constant items to ints on
prepare phase to optimize execution speed. In this case it tries to evaluate
subselect which contains a derived table and is contained in a derived table.
All derived tables are filled only after all derived tables are prepared.
So evaluation of subselect with derived table at the prepare phase will
return a wrong result.
A new flag with_subselect is added to the Item class. It indicates that
expression which this item represents is a subselect or contains a subselect.
It is set to 0 by default. It is set to 1 in the Item_subselect constructor
for subselects.
For Item_func and Item_cond derived classes it is set after fixing any argument
in Item_func::fix_fields() and Item_cond::fix_fields accordingly.
The convert_constant_item() function now doesn't convert a constant item
if the with_subselect flag set in it.
The select statement that specified a view could be
slightly changed when the view was saved in a frm file.
In particular references to an alias name in the HAVING
clause could be substituted for the expression named by
this alias.
This could result in an error message for a query of
the form SELECT * FROM <view>. Yet no such message
appeared when executing the query specifying the view.
- When manually constructing a SEL_TREE for "t.key NOT IN(...)", take into account that
get_mm_parts may return a tree with type SEL_TREE::IMPOSSIBLE
- Added missing OOM checks
- Added comments
over two views when using syntax with curly braces.
Each outer join operation must be placed in a separate
nest. This was not done when the syntax with curly braces
was used. In some cases, in particular, for queries with outer
join operation over views it could cause a crash.
itself when executing queries referring to a view with GROUP BY
an expression containing non-constant interval.
It happened because Item_date_add_interval::eq neglected the
fact that the method can be applied to an expression of the form
date(col) + interval time_to_sec(col) second
at the time when col could not be evaluated yet.
An attempt to evaluate time_to_sec(col) in this method resulted
in a crash.
A pattern to generate binlog for DROPped temp table in close_temporary_tables
was buggy: could not deal with a grave-accent-in-name table.
The fix exploits `append_identifier()' for quoting and duplicating accents.
from within triggers
Add support for passing NEW.x as INOUT and OUT parameters to stored
procedures. Passing NEW.x as INOUT parameter requires SELECT and
UPDATE privileges on that column, and passing it as OUT parameter
requires only UPDATE privilege.
a worse execution plan than in 4.1 for some queries.
It happened due the fact that at some conditions the
optimizer always preferred range or full index scan access
methods to lookup access methods even when the latter were much
cheaper.
The problem was not observed in 4.1 for the reported query
because the WHERE condition was not of a form that could
cause the problem.
Equality propagation introduced on 5.0 added an extra
predicate and changed the WHERE condition. The new condition
provoked the optimizer to make a bad choice.
The problem was fixed by the patch for bug 17379.
When a view statement is compiled on CREATE VIEW time, most of the
optimizations should not be done. Finding the right optimization
for a subquery is one of them.
Unfortunately the optimizer is resolving the column references of
the left expression of IN subqueries in the process of deciding
witch optimization to use (if needed). So there should be a
special case in Item_in_subselect::fix_fields() : check the
validity of the left expression of IN subqueries in CREATE VIEW
mode and then proceed as normal.
garbles data if longer than 766 chars.
The problem is that a stored routine returns BLOBs to the previous
caller, BLOBs are shallow-copied (i.e. only pointers to the data are
copied). The fix is to also copy data of BLOBs.
