query / no aggregate of subquery
The optimizer counts the aggregate functions that
appear as top level expressions (in all_fields) in
the current subquery. Later it makes a list of these
that it uses to actually execute the aggregates in
end_send_group().
That count is used in several places as a flag whether
there are aggregates functions.
While collecting the above info it must not consider
aggregates that are not aggregated in the current
context. It must treat them as normal expressions
instead. Not doing that leads to incorrect data about
the query, e.g. running a query that actually has no
aggregate functions as if it has some (and hence is
expected to return only one row).
Fixed by ignoring the aggregates that are not aggregated
in the current context.
One other smaller omission discovered and fixed in the
process : the place of aggregation was not calculated for
user defined functions. Fixed by calling
Item_sum::init_sum_func_check() and
Item_sum::check_sum_func() as it's done for the rest of
the aggregate functions.
Thanks to Martin Friebe for finding and submitting a fix for this bug!
A table with maximum number of key segments and maximum length key name
would have a corrupted .frm file, due to an incorrect calculation of the
complete key length. Now the key length is computed correctly (I hope) :-)
MyISAM would reject a table with the maximum number of keys and the maximum
number of key segments in all keys. It would allow one less than this total
maximum. Now MyISAM accepts a table defined with the maximum. (This is a
very minor issue.)
a lookup into a BINARY index by a key ended with spaces. It caused
an assertion abort for a debug version and wrong results for non-debug
versions.
The problem occurred because the function _mi_pack_key stripped off
the trailing spaces from binary search keys while the function _mi_make_key
did not do it when keys were inserted into the index.
Now the function _mi_pack_key does not remove the trailing spaces from
search keys if they are of the binary type.
If one sets MYSQL_READ_DEFAULTS_FILE and MYSQL_READ_DEFAULT_GROUP options
after mysql_real_connect() called with that MYSQL instance,
these options will affect next mysql_reconnect then.
As we use a copy of the original MYSQL object inside mysql_reconnect,
and mysql_real_connect frees options.my_cnf_file and _group strings,
we will free these twice when we execute mysql_reconnect with the
same MYSQL for the second time.
I don't think we should ever read defaults files handling mysql_reconnect.
So i just set them to 0 for the temporary MYSQL object there/
LOCK TABLES takes a list of tables to lock. It may lock several
tables successfully and then encounter a tables that it can't lock,
e.g. because it's locked. In such case it needs to undo the locks on
the already locked tables. And it does that. But it has also notified
the relevant table storage engine handlers that they should lock.
The only reliable way to ensure that the table handlers will give up
their locks is to end the transaction. This is what UNLOCK TABLE
does : it ends the transaction if there were locked tables by LOCK
tables.
It is possible to end the transaction when the lock fails in
LOCK TABLES because LOCK TABLES ends the transaction at its start
already.
Fixed by ending (again) the transaction when LOCK TABLES fails to
lock a table.
the loose scan optimization for grouping queries was applied returned
a wrong result set when the query was used with the SQL_BIG_RESULT
option.
The SQL_BIG_RESULT option forces to use sorting algorithm for grouping
queries instead of employing a suitable index. The current loose scan
optimization is applied only for one table queries when the suitable
index is covering. It does not make sense to use sort algorithm in this
case. However the create_sort_index function does not take into account
the possible choice of the loose scan to implement the DISTINCT operator
which makes sorting unnecessary. Moreover the current implementation of
the loose scan for queries with distinct assumes that sorting will
never happen. Thus in this case create_sort_index should not call
the function filesort.
INSERT into table from SELECT from the same table
with ORDER BY and LIMIT was inserting other data
than sole SELECT ... ORDER BY ... LIMIT returns.
One part of the patch for bug #9676 improperly pushed
LIMIT to temporary table in the presence of the ORDER BY
clause.
That part has been removed.
The C optimizer may decide that data access operations
through pointer of different type are not related to
the original data (strict aliasing).
This is what happens in fetch_long_with_conversion(),
when called as part of mysql_stmt_fetch() : it tries
to check for truncation errors by first storing float
(and other types of data) into a char * buffer and then
accesses them through a float pointer.
This is done to prevent the effects of excess precision
when using FPU registers.
However the doublestore() macro converts a double pointer
to an union pointer. This violates the strict aliasing rule.
Fixed by making the intermediary variables volatile (
to not re-introduce the excess precision bug) and using
the intermediary value instead of the char * buffer.
Note that there can be loss of precision for both signed
and unsigned 64 bit integers converted to double and back,
so the check must stay there (even for compatibility
reasons).
Based on the excellent analysis in bug 28400.
The reason the "reap;" succeeds unexpectedly is because the query was completing(almost always) and the network buffer was big enough to store the query result (sometimes) on Windows, meaning the response was completely sent before the server thread could be killed.
Therefore we use a much longer running query that doesn't have a chance to fully complete before the reap happens, testing the kill properly.
- When creating an index for the sort, the number of rows plus 1 is used
to allocate a buffer. In this test case, the number of rows 4294967295
is the max value of an unsigned integer, so when 1 was added to it, a
buffer of size 0 was allocated causing the crash.
- Create new test suite for this bug's test suite as per QA.
long shared-memory-base-names could overflow a static internal buffer
and thus crash mysqld and various clients. change both to dynamic
buffers, show everything but overflowing those buffers still works.
The test case for this would pretty much amount to
mysqld --shared-memory-base-name=HeyMrBaseNameXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX --shared-memory=1 &
mysqladmin --no-defaults --shared-memory-base-name=HeyMrBaseNameXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX shutdown
Unfortunately, we can't just use an .opt file for the
server. The .opt file is used at start-up, before any
include in the actual test can tell mysqltest to skip
this one on non-Windows. As a result, such a test would
break on unices.
Fixing mysql-test-run.pl to export full path for master
and slave would enable us to start a server from within
the test which is ugly and, what's more, doesn't work as
the server blocks (mysqltest offers no fire-and-forget
fork-and-exec), and mysqladmin never gets run.
Making the test rpl_windows_shm or some such so we can
is beyond ugly. As is introducing another file-name based
special case (run "win*.test" only when on Windows). As is
(yuck) coding half the test into mtr (as in, having it
hand out a customized environment conductive to the shm-
thing on Win only).
Situation is exacerbated by the fact that .sh is not
necessary run as expected on Win.
In short, it's just not worth it. No test-case until we
have a new-and-improved test framework.
Occasionally mysqlbinlog --hexdump failed with error:
ERROR 1064 (42000) at line ...: You have an error in your
SQL syntax; check the manual that corresponds to your MySQL
server version for the right syntax to use near
'Query thread_id=... exec_time=... error_code=...
When the length of hexadecimal dump of binlog header was
divisible by 16, commentary sign '#' after header was lost.
The Log_event::print_header function has been modified to always
finish hexadecimal binlog header with "\n# ".
The abort happened when a query contained a conjunctive predicate
of the form 'view column = constant' in the WHERE condition and
the grouping list also contained a reference to a view column yet
a different one.
Removed the failing assertion as invalid in a general case.
Also fixed a bug that prevented applying some optimization for grouping
queries using views. If the WHERE condition of such a query contains
a conjunctive condition of the form 'view column = constant' and
this view column is used in the grouping list then grouping by this
column can be eliminated. The bug blocked performing this elimination.
