The not_null_tables() of Item_func_not_all and Item_in_optimizer was inherited from
Item_func by mistake. It made the optimizer think that subquery
predicates with ALL/ANY/IN were null-rejecting. This could trigger invalid
conversions of outer joins into inner joins.
The failures are missing entries in the slow query log. The reason for the failure are sleep() calls with short duration 10ms, which is less than the default system timer resolution for various WaitForXXXObject functions (15.6 ms) and thus can't work reliably.
The fix is to make sleeps tiny bit longer (20ms from 10ms) in the test.
Optimization of aggregate functions detected constant under max() and evalueted it, but condition in the WHWRE clause (which is always FALSE) was not taken into account
The patch backports two patches from mysql 5.6:
- BUG#12640437: USING SQL_BUFFER_RESULT RESULTS IN A DIFFERENT QUERY OUTPUT
- Bug#12578908: SELECT SQL_BUFFER_RESULT OUTPUTS TOO MANY ROWS WHEN GROUP IS OPTIMIZED AWAY
Original comment:
-----------------
3714 Jorgen Loland 2012-03-01
BUG#12640437 - USING SQL_BUFFER_RESULT RESULTS IN A DIFFERENT
QUERY OUTPUT
For all but simple grouped queries, temporary tables are used to
resolve grouping. In these cases, the list of grouping fields is
stored in the temporary table and grouping is resolved
there (e.g. by adding a unique constraint on the involved
fields). Because of this, grouping is already done when the rows
are read from the temporary table.
In the case where a group clause may be optimized away, grouping
does not have to be resolved using a temporary table. However, if
a temporary table is explicitly requested (e.g. because the
SQL_BUFFER_RESULT hint is used, or the statement is
INSERT...SELECT), a temporary table is used anyway. In this case,
the temporary table is created with an empty group list (because
the group clause was optimized away) and it will therefore not
create groups. Since the temporary table does not take care of
grouping, JOIN::group shall not be set to false in
make_simple_join(). This was fixed in bug 12578908.
However, there is an exception where make_simple_join() should
set JOIN::group to false even if the query uses a temporary table
that was explicitly requested but is not strictly needed. That
exception is if the loose index scan access method (explain
says "Using index for group-by") is used to read into the
temporary table. With loose index scan, grouping is resolved
by the access method. This is exactly what happens in this bug.
This is a backport of the fix for MySQL bug #13723054 in 5.6.
Original comment:
The crash is caused by arbitrary memory area owerwriting in case of
BLOB fields during attempt to copy BLOB field key image into record
buffer(record buffer is too small to get BLOB key part image).
note:
QUICK_GROUP_MIN_MAX_SELECT can not work with BLOB fields
because it uses record buffer as temporary buffer for key values
however this case is filtered out by covering_keys() check
in get_best_group_min_max() as BLOBs always require key length
modificator in the key declaration and if the key has a BLOB
then it can not be covered key.
The fix is to use 'max_used_key_length' key length instead of 0.
Analysis:
Spcifically the crash in this bug was a result of the call to key_copy()
that copied the whole key, inlcuding the BLOB field which is not used
for index access. Copying the blob field overwrote memory as far as the
function parameter 'key_info'. As a result the contents of key_info was
all 0, which resulted in a crash when this key_info was accessed few
lines below in key_cmp().
The problem was in the code (update_const_equal_items()) which marked
index parts constant independently of the place where the equality was used.
In the test suite it marked t2_1.c part constant despite the fact that
it connected by OR with other expression.
Solution is to mark constant only top equalities connected with AND.
This bug is a duplicate of Bug #31173, which was pushed to the
mysql-trunk 5.6 on 4th Aug, 2010. This is just a back-port of
the fix
mysql-test/r/mysqlslap.result:
A test added as part of the fix for Bug #59107
mysql-test/t/mysqlslap.test:
A test added as part of the fix for Bug #59107
Bug#13639204 64111: CRASH ON SELECT SUBQUERY WITH NON UNIQUE INDEX
The crash happened due to wrong calculation
of key length during creation of reference for
sort order index. The problem is that
keyuse->used_tables can have OUTER_REF_TABLE_BIT enabled
but used_tables parameter(create_ref_for_key() func) does
not have it. So key parts which have OUTER_REF_TABLE_BIT
are ommited and it could lead to incorrect key length
calculation(zero key length).
mysql-test/r/subselect_innodb.result:
test result
mysql-test/t/subselect_innodb.test:
test case
sql/sql_select.cc:
added OUTER_REF_TABLE_BIT to the used_tables parameter
for create_ref_for_key() function.
storage/innobase/handler/ha_innodb.cc:
added assertion, request from Inno team
storage/innodb_plugin/handler/ha_innodb.cc:
added assertion, request from Inno team
The main problem was a bug in CSV where it provided wrong statistics (it claimed the table was empty when it wasn't)
I also fixed wrong freeing of blob's in the CSV handler. (Any call to handler::read_first_row() on a CSV table with blobs would fail)
mysql-test/r/csv.result:
Added new test case
mysql-test/r/partition_innodb.result:
Updated test results after fixing bug with impossible partitions and const tables
mysql-test/t/csv.test:
Added new test case
sql/sql_select.cc:
Cleaned up code for handling of partitions.
Fixed also a bug where we didn't threat a table with impossible partitions as a const table.
storage/csv/ha_tina.cc:
Allocate blobroot onces.
Fixed that repair removes the 'table is moved' mark.
mysql-test/suite/maria/r/maria-autozerofill.result:
Test case for lp:967914
mysql-test/suite/maria/t/maria-autozerofill.test:
Test case for lp:967914
storage/maria/ha_maria.cc:
Fixed that repair removes the 'table is moved' mark.
The issue was that check/optimize/anaylze did not zerofill the table before they started to work on it.
Added one more element to not often used function handler::auto_repair() to allow handler to decide when to auto repair.
mysql-test/suite/maria/r/maria-autozerofill.result:
Test case for lp:944422
mysql-test/suite/maria/t/maria-autozerofill.test:
Test case for lp:944422
sql/ha_partition.cc:
Added argument to auto_repair()
sql/ha_partition.h:
Added argument to auto_repair()
sql/handler.h:
Added argument to auto_repair()
sql/table.cc:
Let auto_repair() decide which errors to trigger auto-repair
storage/archive/ha_archive.h:
Added argument to auto_repair()
storage/csv/ha_tina.h:
Added argument to auto_repair()
storage/maria/ha_maria.cc:
Give better error & warning messages for auto-repaired tables.
storage/maria/ha_maria.h:
Added argument to auto_repair()
Always auto-repair in case of moved table.
storage/maria/ma_open.c:
Remove special handling of HA_ERR_OLD_FILE (this is now handled in auto_repair())
storage/myisam/ha_myisam.h:
Added argument to auto_repair()
Analysis:
-------------------------------
According to the Manual
(http://dev.mysql.com/doc/refman/5.1/en/identifier-case-sensitivity.html):
"Column, index, stored routine, and event names are not case sensitive on any
platform, nor are column aliases."
In other words, 'lower_case_table_names' does not affect the behaviour of
those identifiers.
On the other hand, trigger names are case sensitive on some platforms,
and case insensitive on others. 'lower_case_table_names' does not affect
the behaviour of trigger names either.
The bug was that SHOW statements did case sensitive comparison
for stored procedure / stored function / event names.
Fix:
Modified the code so that comparison in case insensitive for routines
and events for "SHOW" operation.
As part of this commit, only fixing the test failures due to the actual code fix.
Analysis:
-------------------------------
According to the Manual
(http://dev.mysql.com/doc/refman/5.1/en/identifier-case-sensitivity.html):
"Column, index, stored routine, and event names are not case sensitive on any
platform, nor are column aliases."
In other words, 'lower_case_table_names' does not affect the behaviour of
those identifiers.
On the other hand, trigger names are case sensitive on some platforms,
and case insensitive on others. 'lower_case_table_names' does not affect
the behaviour of trigger names either.
The bug was that SHOW statements did case sensitive comparison
for stored procedure / stored function / event names.
Fix:
Modified the code so that comparison in case insensitive for routines
and events for "SHOW" operation.
The test case must insert all the records using a single transaction. Otherwise the test
case takes more than 15 minutes and will time out in pb2 and mtr.
BUG#64503: mysql frequently ignores --relay-log-space-limit
When the SQL thread goes to sleep, waiting for more events, it sets
the flag ignore_log_space_limit to true. This gives the IO thread a
chance to queue some more events and ultimately the SQL thread will be
able to purge the log once it is rotated. By then the SQL thread
resets the ignore_log_space_limit to false. However, between the time
the SQL thread has set the ignore flag and the time it resets it, the
IO thread will be queuing events in the relay log, possibly going way
over the limit.
This patch makes the IO and SQL thread to synchronize when they reach
the space limit and only ask for one event at a time. Thus the SQL
thread sets ignore_log_space_limit flag and the IO thread resets it to
false everytime it processes one more event. In addition, everytime
the SQL thread processes the next event, and the limit has been
reached, it checks if the IO thread should rotate. If it should, it
instructs the IO thread to rotate, giving the SQL thread a chance to
purge the logs (freeing space). Finally, this patch removes the
resetting of the ignore_log_space_limit flag from purge_first_log,
because this is now reset by the IO thread every time it processes the
next event when the limit has been reached.
If the SQL thread is in a transaction, it cannot purge so, there is no
point in asking the IO thread to rotate. The only thing it can do is
to ask for more events until the transaction is over (then it can ask
the IO to rotate and purge the log right away). Otherwise, there would
be a deadlock (SQL would not be able to purge and IO thread would not
be able to queue events so that the SQL would finish the transaction).
Problem: Grouping results by VALUES(alias for string literal) causes
the server to crash.
Item_insert_values is not constructed to handle other types of
arguments than field and reference to field. In this case, the
argument is an Item_string, and this causes
Item_insert_values::fix_fields() to crash.
Fix: Issue an error message when the argument to Item_insert_values is
not a field or a reference to a field.
This is slightly in breach with documentation, which states that
VALUES should return NULL, but the error message is only issued in
cases where the server otherwise would crash, so there is no change in
behavior for queries that already work. Future versions will restrict
syntax so that using VALUES in this way is illegal.
mysql-test/r/errors.result:
Add test case for bug #13031606.
mysql-test/t/errors.test:
Add test case for bug #13031606.
sql/item.cc:
Issue error message if argument is not field or reference to field.
This bug was introduced into mariadb 5.2 in the December 2010 with
the patch that added a new engine property: the ability to support
virtual columns.
As a result of this bug the information from frm files for tables
that contained virtual columns did not appear in the information schema
tables.
If in the where clause of the a query some comparison conditions on the
field under a MIN/MAX aggregate function contained constants whose sizes
exceeded the size of the field then the query could return a wrong result
when the optimizer had chosen to apply the MIN/MAX optimization.
With such conditions the MIN/MAX optimization still could be applied, yet
it would require a more thorough analysis of the keys built to find
the value of MIN/MAX aggregate functions with index look-ups.
The current patch just prohibits using the MIN/MAX optimization in this
situation.
truncating, inserting the same set of rows. When a table is
re-created with the same set of rows, the data file size must
not grow.
rb:968
Approved by Marko.
