subquery returning multiple rows
Error handling was missing when handling subqueires in WHERE
and when assigning a SELECT result to a @variable.
This caused crash(es).
Fixed by adding error handling code to both the WHERE
condition evaluation and to assignment to an @variable.
having clause...
The fix for bug 46184 was not very complete. It was not covering
views using temporary tables and multiple tables in a FROM clause.
Fixed by reverting the fix for 46184 and making a more general
check that is checking at the right execution stage and for all
of the non-supported cases.
Now PROCEDURE ANALYZE on non-top level SELECT is also forbidden.
Updated the analyse.test and subselect.test accordingly.
Queries with nested outer joins may lead to crashes or
bad results because an internal data structure is not handled
correctly.
The optimizer uses bitmaps of nested JOINs to determine
if certain table can be placed at a certain place in the
JOIN order.
It does maintain a bitmap describing in which JOINs
last placed table is nested.
When it puts a table it makes sure the bit of every JOIN that
contains the table in question is set (because JOINs can be nested).
It does that by recursively setting the bit for the next enclosing
JOIN when this is the first table in the JOIN and recursively
resetting the bit if it's the last table in the JOIN.
When it removes a table from the join order it should do the
opposite : recursively unset the bit if it's the only remaining
table in this join and and recursively set the bit if it's removing
the last table of a JOIN.
There was an error in how the bits was set for the upper levels :
when removing a table it was setting the bit for all the enclosing
nested JOINs even if there were more tables left in the current JOIN
(which practically means that the upper nested JOINs were not affected).
Fixed by stopping the recursion at the relevant level.
Problem 1:
column_priv_hash uses utf8_general_ci collation
for the key comparison. The key consists of user name,
db name and table name. Thus user with privileges on table t1
is able to perform the same operation on T1
(the similar situation with user name & db name, see acl_cache).
So collation which is used for column_priv_hash and acl_cache
should be case sensitive.
The fix:
replace system_charset_info with my_charset_utf8_bin for
column_priv_hash and acl_cache
Problem 2:
The same situation with proc_priv_hash, func_priv_hash,
the only difference is that Routine name is case insensitive.
So the fix is to use my_charset_utf8_bin for
proc_priv_hash & func_priv_hash and convert routine name into lower
case before writing the element into the hash and
before looking up the key.
Additional fix: mysql.procs_priv Routine_name field collation
is changed to utf8_general_ci.
It's necessary for REVOKE command
(to find a field by routine hash element values).
Note:
It's safe for lower-case-table-names mode too because
db name & table name are converted into lower case
(see GRANT_NAME::GRANT_NAME).
If the first argument to GeomFromWKB function is a geometry
field then the function just returns its value.
However in doing so it's not preserving first argument's
null_value flag and this causes unexpected null value to
be returned to the calling function.
Fixed by updating the null_value of the GeomFromWKB function
in such cases (and all other cases that return a NULL e.g.
because of not enough memory for the return buffer).
Problem: involving a spatial index for "non-spatial" queries
(that don't containt MBRXXX() functions) may lead to failed assert.
Fix: don't use spatial indexes in such cases.
line 138 when forcing a spatial index
Problem: "Spatial indexes can be involved in the search
for queries that use a function such as MBRContains()
or MBRWithin() in the WHERE clause".
Using spatial indexes for JOINs with =, <=> etc.
predicates is incorrect.
Fix: disable spatial indexes for such queries.
grants are reapplied.
After renaming a user and trying to re-apply grants results in additional
grants.
This is because we use username as part of the key for GRANT_TABLE structure.
When the user is renamed, we only change the username stored and the hash key
still contains the old user name and this results in the extra privileges
Fixed by rebuilding the hash key and updating the column_priv_hash structure
when the user is renamed
If a thread is killed in the server, we throw "shutdown" only if one is actually in
progress; otherwise, we throw "query interrupted".
Control-C in the mysql command-line client is "incremental" now.
First Control-C sends KILL QUERY (when connected to 5.0+ server, otherwise, see next)
Next Control-C sends KILL CONNECTION
Next Control-C aborts client.
As the first two steps only pertain to an existing query,
Control-C will abort the client right away if no query is running.
client will give more detailed/consistent feedback on Control-C now.
can lead to bad memory access
Problem: Field_bit is the only field which returns INT_RESULT
and doesn't have unsigned flag. As it's not a descendant of the
Field_num, so using ((Field_num *) field_bit)->unsigned_flag may lead
to unpredictable results.
Fix: check the field type before casting.
The pthread_cond_wait implementations for windows might
dead lock in some rare circumstances.
1) One thread (I) enter a timed wait and at a point in
time ends up after mutex unlock and before
WaitForMultipleObjects(...)
2) Another thread (II) enters pthread_cond_broadcast.
Grabs the mutex and discovers one waiter. It set
the broadcast event and closes the broadcast gate
then unlocks the mutex.
3) A third thread (III) issues a pthread_cond_signal.
It grabs the mutex, discovers one waiter, sets the
signal event then unlock the mutex.
4) The first threads (I) enters WaitForMultipleObjects
and finds out that the signal object is in a
signalled state and exits the wait.
5) Thread (I) grabs the mutex and checks result status.
The number of waiters is decreased and becomes equal
to 0. The event returned was a signal event so the
broadcast gate isn't opened. The mutex is released.
6) Thread (II) issues a new broadcast. The mutex is
acquired but the number of waiters are 0 hence
the broadcast gate remains closed.
7) Thread (I) enters the wait again but is blocked by
the broadcast gate.
This fix resolves the above issue by always resetting
broadcast gate when there are no more waiters in th queue.
On Mac OS X or Windows, sending a SIGHUP to the server or a
asynchronous flush (triggered by flush_time), would cause the
server to crash.
The problem was that a hook used to detach client API handles
wasn't prepared to handle cases where the thread does not have
a associated session.
The solution is to verify whether the thread has a associated
session before trying to detach a handle.
'flush tables' crashes
The server crashes when 'show procedure status' and 'flush tables' are
run concurrently.
This is caused by the way mysql.proc table is added twice to the list
of table to lock although the requirements on the current locking API
assumes differently.
No test case is submitted because of the nature of the crash which is
currently difficult to reproduce in a deterministic way.
This is a backport from 5.1
> ------------------------------------------------------------
> revno: 2796
> revision-id: sergey.glukhov@sun.com-20090827102219-sgjz0v5t1rfccs14
> parent: joro@sun.com-20090824122803-1d5jlaysjc7a7j6q
> committer: Sergey Glukhov <Sergey.Glukhov@sun.com>
> branch nick: mysql-5.0-bugteam
> timestamp: Thu 2009-08-27 15:22:19 +0500
> message:
> Bug#46184 Crash, SELECT ... FROM derived table procedure analyze
> The crash happens because select_union object is used as result set
> for queries which have derived tables.
> select_union use temporary table as data storage and if
> fields count exceeds 10(count of values for procedure ANALYSE())
> then we get a crash on fill_record() function.
> ------------------------------------------------------------
> revno: 2791.2.3
> revision-id: joro@sun.com-20090827114042-h55n7qp9990bl6ge
> parent: anurag.shekhar@sun.com-20090831073231-e55y1hsck6n08ux8
> committer: Georgi Kodinov <joro@sun.com>
> branch nick: B46749-5.0-bugteam
> timestamp: Thu 2009-08-27 14:40:42 +0300
> message:
> Bug #46749: Segfault in add_key_fields() with outer subquery level
> field references
>
> This error requires a combination of factors :
> 1. An "impossible where" in the outermost SELECT
> 2. An aggregate in the outermost SELECT
> 3. A correlated subquery with a WHERE clause that includes an outer
> field reference as a top level WHERE sargable predicate
>
> When JOIN::optimize detects an "impossible WHERE" it will bail out
> without doing the rest of the work and initializations. It will not
> call make_join_statistics() as well. And make_join_statistics fills
> in various structures for each table referenced.
> When processing the result of the "impossible WHERE" the query must
> send a single row of data if there are aggregate functions in it.
> In this case the server marks all the aggregates as having received
> no rows and calls the relevant Item::val_xxx() method on the SELECT
> list. However if this SELECT list happens to contain a correlated
> subquery this subquery is evaluated in a normal evaluation mode.
> And if this correlated subquery has a reference to a field from the
> outermost "impossible where" SELECT the add_key_fields will mistakenly
> consider the outer field reference as a "local" field reference when
> looking for sargable predicates.
> But since the SELECT where the outer field reference refers to is not
> completely initialized due to the "impossible WHERE" in this level
> we'll get a NULL pointer reference.
> Fixed by making a better condition for discovering if a field is "local"
> to the SELECT level being processed.
> It's not enough to look for OUTER_REF_TABLE_BIT in this case since
> for outer references to constant tables the Item_field::used_tables()
> will return 0 regardless of whether the field reference is from the
> local SELECT or not.
The 'BEGIN/COMMIT/ROLLBACK' log event could be filtered out if the
database is not selected by --database option of mysqlbinlog command.
This can result in problem if there are some statements in the
transaction are not filtered out.
To fix the problem, mysqlbinlog will output 'BEGIN/ROLLBACK/COMMIT'
in regardless of the database filtering rules.
replication
MySQL server uses wrong lock type (always TL_READ instead of
TL_READ_NO_INSERT when appropriate) for tables used in
subqueries of UPDATE statement. This leads in some cases to
a broken replication as statements are written in the wrong
order to the binlog.
