CASES RESETS DATA POINTER TO SMAL
ISSUE: Myisamchk doing sort recover
on a table reduces data_file_length.
Maximum size of data file decreases,
lesser number of rows are stored.
SOLUTION: Size of data_file_length is
fixed to the original length.
CASES RESETS DATA POINTER TO SMAL
ISSUE: Myisamchk doing sort recover
on a table reduces data_file_length.
Maximum size of data file decreases,
lesser number of rows are stored.
SOLUTION: Size of data_file_length is
fixed to the original length.
BUG#13519696 - 62940: SELECT RESULTS VARY WITH VERSION AND
WITH/WITHOUT INDEX RANGE SCAN
BUG#13453382 - REGRESSION SINCE 5.1.39, RANGE OPTIMIZER WRONG
RESULTS WITH DECIMAL CONVERSION
BUG#13463488 - 63437: CHAR & BETWEEN WITH INDEX RETURNS WRONG
RESULT AFTER MYSQL 5.1.
Those are all cases where the range optimizer got it wrong
with > and >=.
Bug#12985021 SIMPLE QUERY WITH DECIMAL NUMBERS TAKE AN
When parsing the fractional part of a string which
is to be converted to double, we can stop after a few digits:
the extra digits will not contribute to the actual result anyways.
Bug#11758543 50756: BIGINT '100' MATCHES 1.001E2
Expressions of the form
BIGINT_COL <compare> <non-integer constant>
should be done either as decimal, or float.
Currently however, such comparisons are done as int,
which means that the constant may be truncated,
and yield false positives/negatives for all queries
where compare is '>' '<' '>=' '<=' '=' '!='.
BIGINT_COL IN <list of contstants>
and
BIGINT_COL BETWEEN <constant> AND <constant>
are also affected.
MEMORY LEAK.
Background:
- There are caches for stored functions and stored procedures (SP-cache);
- There is no similar cache for events;
- Triggers are cached together with TABLE objects;
- Those SP-caches are per-session (i.e. specific to each session);
- A stored routine is represented by a sp_head-instance internally;
- SP-cache basically contains sp_head-objects of stored routines, which
have been executed in a session;
- sp_head-object is added into the SP-cache before the corresponding
stored routine is executed;
- SP-cache is flushed in the end of the session.
The problem was that SP-cache might grow without any limit. Although this
was not a pure memory leak (the SP-cache is flushed when session is closed),
this is still a problem, because the user might take much memory by
executing many stored routines.
The patch fixes this problem in the least-intrusive way. A soft limit
(similar to the size of table definition cache) is introduced. To represent
such limit the new runtime configuration parameter 'stored_program_cache'
is introduced. The value of this parameter is stored in the new global
variable stored_program_cache_size that used to control the size of SP-cache
to overflow.
The parameter 'stored_program_cache' limits number of cached routines for
each thread. It has the following min/default/max values given from support:
min = 256, default = 256, max = 512 * 1024.
Also it should be noted that this parameter limits the size of
each cache (for stored procedures and for stored functions) separately.
The SP-cache size is checked after top-level statement is parsed.
If SP-cache size exceeds the limit specified by parameter
'stored_program_cache' then SP-cache is flushed and memory allocated for
cache objects is freed. Such approach allows to flush cache safely
when there are dependencies among stored routines.
This patch changes the mechanism by which the client enables a
plugin. Instead of using INSERT IGNORE to reload a plugin library,
it now uses REPLACE INTO. This allows users to load a library
multiple times replacing the existing values in the mysql.plugin
table. This allows users to replace the symbol reference to a
different dl name in the table. Thus permitting enabling of
multiple versions of the same library without first disabling
the old version.
A regression test was added to ensure this feature works.
- Reverting the patch for Bug # 12584302
The patch will be reverted in 5.1 and 5.5.
The patch will not be reverted in 5.6, the change will
be properly documented in 5.6.
- Backporting DBUG_ASSERT not to crash on '0000-01-00'
(already fixed in mysql-trunk (5.6))
Introducing new collations:
utf8_general_mysql500_ci and ucs2_general_mysql500_ci,
to reproduce behaviour of utf8_general_ci and ucs2_general_ci
from mysql-5.1.23 (and earlier).
The collations are added to simplify upgrade from mysql-5.1.23 and earlier.
Note: The patch does not make new server start over old data automatically.
Some manual upgrade procedures are assumed.
Paul: please get in touch with me to discuss upgrade procedures
when documenting this bug.
modified:
include/m_ctype.h
mysql-test/r/ctype_utf8.result
mysql-test/t/ctype_utf8.test
mysys/charset-def.c
strings/ctype-ucs2.c
strings/ctype-utf8.c
The issue is that xa.test failed sporadically on some platforms.
The reason for the test failure is a race condition in xa.test.
The race condition occures between connection that executes statement
INSERT INTO t2 SELECT FROM t1 and other connection that tries to run
statements DELETE FROM t1 and COMMIT. If COMMIT statement had been executed
before the statement INSERT INTO t2 SELECT FROM t1 was locked by lock
on table t1 (as a result of query from table t1) then the INSERT statement
is executed successfully and a following test for deadlock would failed.
This patch fixes this race condition by moving COMMIT statement after commit
of distributed transaction from concurrent session.
Fixing the 5.5 part (the 5.6 part will go in a separate commit soon).
Problem:
Item_direct_ref::get_date() incorrectly calculated its "null_value",
which made UNIX_TIMESTAMP(view_column) incorrectly return NULL
for a NOT NULL view_column.
Fix:
Make Item_direct_ref::get_date() calculate null_value
in the similar way with the other methods
(val_real,val_str,val_int,val_decimal):
copy null_value from the referenced Item.
modified:
mysql-test/r/func_time.result
mysql-test/t/func_time.test
sql/item.cc
routines.
mysqldump in xml mode did not dump routines, events or
triggers.
This patch fixes this issue by fixing the if conditions
that disallowed the dump of above mentioned objects in
xml mode, and added the required code to enable dump
in xml format.
If init_command was incorrect, we couldn't let users execute
queries, but we couldn't report the issue to the client either
as it does not expect error messages before even sending a
command. Thus, we simply disconnected them without throwing
a clear error.
We now go through the proper sequence once (without executing
any user statements) so we can report back what the problem
is. Only then do we disconnect the user.
As always, root remains unaffected by this as init_command is
(still) not executed for them.
--FLUSH-LOG BREAKS CONSISTENCY
The transaction started by mysqldump gets committed
implicitly when flush-log is specified along with
single-transaction option, and hence can break
consistency.
This is because, COM_REFRESH is executed in order
to flush logs and starting from 5.5 this command
performs an implicit commit.
Fixed by making sure that COM_REFRESH is executed
before the transaction has started and not after it.
Note : This patch triggers following behavioral
changes in mysqldump :
1) After this patch we no longer flush logs before
dumping each database if --single-transaction
option is given like it was done before (in the
absence of --lock-all-tables and --master-data
options).
2) Also, after this patch, we start acquiring
FTWRL before flushing logs in cases when only
--single-transaction and --flush-logs are given.
It becomes safe to use mysqldump with these two
options and without --master-data parameter for
backups.
unix_timestamp() is implemented in this part of the code in place of current_time().
Also, since the pb2 machines may be extremely fast, instead of looping through the code,
we use sleep(1.1) so that the variables t0 and t1 have different values.
The time comparison using current_time() stored in an int variable was giving wrong results as
the current_time() format as an int implementation has been changed in mysql-trunk but not in mysql-5.5.
The time is stored in the format hh:mm:ss as 'time' datatype.But as an int, it is stored as hhmmss,
but only on the trunk. On mysql-5.5,as an int, it is stored as hh.
Hence, the current_time() function has been changed to unix_timestamp() function.
Problem description:
When a view is created using function FORMAT and if FORMAT function uses locale
option,definition of view saved into server doesn't contain that locale information,
Ex:
create table test2 (bb decimal (10,2));
insert into test2 values (10.32),(10009.2),(12345678.21);
create view test3 as select format(bb,1,'sk_SK') as cc from test2;
select * from test3;
+--------------+
| cc |
+--------------+
| 10.3 |
| 10,009.2 |
| 12,345,678.2 |
+--------------+
3 rows in set (0.02 sec)
show create view test3
View: test3
Create View: CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost`
SQL SECURITY DEFINER VIEW `test3` AS select format(`test2`.`bb`,1) AS `cc`
from `test2`
character_set_client: latin1
collation_connection: latin1_swedish_ci
1 row in set (0.02 sec)
Problem Analysis:
The function Item_func_format::print() which prints the query string to create
the view does not print the third argument (i.e the locale information). Hence
view is created without locale information.
Problem Solution:
If argument count is more than 2 we now print the third argument onto the query string.
Files changed:
sql/item_strfunc.cc
Function call changes: Item_func_format::print()
mysql-test/t/select.test
Added test case to test the bug
mysql-test/r/select.result
Result of the test case appended here
SMALL KEY CACHE
The server crashed on division by zero because the key cache was not
initialized and the block length was 0 which was used in a division.
The fix was to not allow CACHE INDEX if the key cache was not initiallized.
Thus never try LOAD INDEX INTO CACHE for an uninitialized key cache.
Also added some windows files/directories to .bzrignore.
The predicate is re-written from
((`test`.`g1`.`a` = geometryfromtext('')) or ...
to
((`test`.`g1`.`a` = <cache>(geometryfromtext(''))) or ...
The range optimizer calls save_in_field_no_warnings, in order to fetch keys.
save_in_field_no_warnings returns 0 because of the cache wrapper,
and get_mm_leaf() proceeded to call Field_blob::get_key_image()
which accesses un-initialized data.
AND HANG IN SHOW TABLE STATUS.
ISSUE: Table corruption due to concurrent queries.
Different threads running insert and check
query leads to table corruption. Not properly locked,
rows are inserted in between check query.
SOLUTION: In check query mutex lock is acquired
for a longer time to handle concurrent
insert and check query.
NOTE: Additionally we backported the fix for CHECKSUM
issue(bug#11758979).
A patch for alter_table-big.test has been committed earlier.
This is a patch for create-big.test:
The test used to time-out after 900 seconds.
It relied on debug sleeps that are no longer present in the
code. Since the sleeps are long gone, fixing the problem didn't
involve just updating the result file or using macro
"show_binlog_events2.inc" instead of "show binlog events"
statement. The test needed to be rewritten using debug sync
points, and result then needed to be updated.
So, the sleeps have been replaced by debug_sync points and the test execution time has
been reduced significantly.
BY CACHING OR REDUCING CREATEEVENT CALLS".
5.5 versions of MySQL server performed worse than 5.1 versions
under single-connection workload in autocommit mode on Windows XP.
Part of this slowdown can be attributed to overhead associated
with constant creation/destruction of MDL_lock objects in the MDL
subsystem. The problem is that creation/destruction of these
objects causes creation and destruction of associated
synchronization primitives, which are expensive on Windows XP.
This patch tries to alleviate this problem by introducing a cache
of unused MDL_object_lock objects. Instead of destroying such
objects we put them into the cache and then reuse with a new
key when creation of a new object is requested.
To limit the size of this cache, a new --metadata-locks-cache-size
start-up parameter was introduced.
OPTION SKIP-WRITE-BINLOG
System tables were not getting upgraded when
mysql_upgrade was run with --skip-write-binlog
option. (Same for --write-binlog.) Also, with
this option, mysql_upgrade_info file was not
getting created after the upgrade.
mysql_upgrade makes use of mysql client tool in
order to run upgrade scripts, while doing so it
passes some of the command line options (used to
start mysql_upgrade) directly to mysql client.
The reason behind this bug being, some options
like skip-write-binlog and upgrade-system-tables
were being passed to mysql tool along with other
options, and hence mysql execution failed due
presence of these invalid options.
Fixed this issue by filtering out the above mentioned
options from the list of options that will be passed to
mysql and mysqlcheck tools. However, since --write-binlog
is supported by mysqlcheck, this option would be used
explicitly while running mysqlcheck. (not part of patch,
already there)
Checking the contents of general log after the upgrade
is not doable via an mtr test. So performed manual test.
Added a test to verify the creation of mysql_upgrade_info.
alter_treable-big.test was failing due to the use of RAND() function which is no more
replication safe.
This has been modified using static values.
Also, 'sleep' has been replaced using 'debug_sync' and the execution time of the
test has been reduced significantly.
This test is now taken out of the disabled.def file and is being enabled.
A patch for this bug has already been pushed. A minor change is made here.
The database to be used after re-enabling the disabled code is 'TEST'.
But instead, 'MYSQL' was being used.
This is the minor change that is being made here.
Don't do this for echo, instead:
1) Enable replacements also for assignment from backquoted SQL
2) Allow replace_regex to take a variable for the *entire* argument list
With this, the test can be amended, but only in its version in trunk
