(Fixing both InnoDB and XtraDB)
Re-opening a TABLE object (after e.g. FLUSH TABLES or open table cache
eviction) causes ha_innobase to call
dict_stats_update(DICT_STATS_FETCH_ONLY_IF_NOT_IN_MEMORY).
Inside this call, the following is done:
dict_stats_empty_table(table);
dict_stats_copy(table, t);
On the other hand, commands like UPDATE make this call to get the "rows in
table" statistics in table->stats.records:
ha_innobase->info(HA_STATUS_VARIABLE|HA_STATUS_NO_LOCK)
note the HA_STATUS_NO_LOCK parameter. It means, no locks are taken by
::info() If the ::info() call happens between dict_stats_empty_table
and dict_stats_copy calls, the UPDATE's optimizer will get an estimate
of table->stats.records=1, which causes it to pick a full table scan,
which in turn will take a lot of row locks and cause other bad
consequences.
commit ef92aaf9ec
Author: Jan Lindström <jan.lindstrom@mariadb.com>
Date: Wed Jun 22 22:37:28 2016 +0300
MDEV-10083: Orphan ibd file when playing with foreign keys
Analysis: row_drop_table_for_mysql did not allow dropping
referenced table even in case when actual creating of the
referenced table was not successfull if foreign_key_checks=1.
Fix: Allow dropping referenced table even if foreign_key_checks=1
if actual table create returned error.
Fix the following two build warnings so that 5.5 can be compiled
with GCC5.
storage/innobase/dict/dict0crea.c:1143:21: error: logical not is only applied
to the left hand side of comparison [-Werror=logical-not-parentheses]
ut_a(!node->index == (err != DB_SUCCESS));
^
storage/innobase/log/log0recv.c:1770:20: error: logical not is only applied
to the left hand side of comparison [-Werror=logical-not-parentheses]
ut_ad(!allow_ibuf == mutex_own(&log_sys->mutex));
^
while according to Storage Engine API column names should be compared
case insensitively. This can cause FRM and InnoDB data dictionary to
go out of sync.
There is several different ways to incorrectly define
foreign key constraint. In many cases earlier MariaDB
versions the error messages produced by these cases
are not very clear and helpful. This patch improves
the warning messages produced by foreign key parsing.
Problem:
If we add a referential integrity constraint with a duplicate
name, an error occurs. The foreign key object would not have
been added to the dictionary cache. In the error path, there
is an attempt to remove this foreign key object. Since this
object is not there, the search returns a NULL result.
De-referencing the null object results in this crash.
Solution:
If the search to the foreign key object failed, then don't
attempt to access it.
rb#9309 approved by Marko.
Analysis: MySQL table definition contains also virtual columns. Similarly,
index fielnr references MySQL table fields. However, InnoDB table definition
does not contain virtual columns. Therefore, when matching MySQL key fieldnr
we need to use actual column name to find out referenced InnoDB dictionary
column name.
Fix: Add new function to match MySQL index key columns to InnoDB dictionary.
when created FK
Analysis: Table name is on filename charset but foreign key
identifiers are not. This lead incorrect foreign key
identifier number to be used.
Fix: Convert foreign key identifier to filename charset before
comparing it to table name when largest foreign key identifier
number is resolved.
Analysis: after a red-black-tree lookup we use node withouth
checking did lookup succeed or not. This lead to situation
where NULL-pointer was used.
Fix: Add additional check that found node from red-back-tree
is valid.
Problem:
This is a coding mistake during error handling. When the specified foreign
key constraint is wrong because of data type mismatch, the resulting
foreign key object will not have valid foreign->id (it will be NULL.)
Solution:
While removing the foreign key object from dictionary cache during error
handling, ensure that foreign->id is not null before using it.
rb#8204 approved by Sunny.
causes server crash
Analysis: If wrong data types used on foreign constraint there
was possibility that foreign->id is NULL when incorrect
foreign constraint was removed from the dictionary cache.
Fix: Add guard foreign->id != NULL before trying to lookup
or remove the foreign constraint from dictionary cache.
Tested using user database where problem was repeatable.
Problem:
In the function dict_foreign_remove_from_cache(), the rb tree was updated
without actually verifying whether the given foreign key object is there in the
rb tree or not. There can be an existing foreign key object with the same id
in the rb tree, which must not be removed. Such a scenario comes when an
attempt is made to add a foreign key object with a duplicate identifier.
Solution:
When the foreign key object is removed from the dictionary cache, ensure
that the foreign key object removed from the rbt is the correct one.
rb#7168 approved by Jimmy and Marko.
Problem:
In the function dict_foreign_remove_from_cache(), the rb tree was updated
without actually verifying whether the given foreign key object is there in the
rb tree or not. There can be an existing foreign key object with the same id
in the rb tree, which must not be removed. Such a scenario comes when an
attempt is made to add a foreign key object with a duplicate identifier.
Solution:
When the foreign key object is removed from the dictionary cache, ensure
that the foreign key object removed from the rbt is the correct one.
rb#7168 approved by Jimmy and Marko.
dict_set_corrupted(): Use the canonical way of searching for
less-than-equal (PAGE_CUR_LE) and then checking low_match.
The code that was introduced in MySQL 5.5.17 in
Bug#11830883 SUPPORT "CORRUPTED" BIT FOR INNODB TABLES AND INDEXES
could position the cursor on the page supremum, and then attempt
to overwrite non-existing 7th field of the 1-field supremum record.
Approved by Jimmy Yang
dict_set_corrupted(): Use the canonical way of searching for
less-than-equal (PAGE_CUR_LE) and then checking low_match.
The code that was introduced in MySQL 5.5.17 in
Bug#11830883 SUPPORT "CORRUPTED" BIT FOR INNODB TABLES AND INDEXES
could position the cursor on the page supremum, and then attempt
to overwrite non-existing 7th field of the 1-field supremum record.
Approved by Jimmy Yang
Merged Facebook commit dd2d11be7aaf3be270e740fb95cbc4eacb52f4d7
authored by Rongrong Zhong from https://github.com/facebook/mysql-5.6
This fixes MySQL Bug #68220 innodb_rows_updated is misleading on slave
http://bugs.mysql.com/bug.php?id=68220
Added innodb_system_rows_read/inserted/updated/deleted counters
that are the equivalent of innodb_rows_* but that only account for
changes made to system databases (mysql, information_schame and
preformance_schema). These counters will be used on slaves to
differentiated the updates made on system databases from those made on
user databases.
innodb_rows_* status counters are not updated when innodb_system_rows_*
are updated.
dd2d11be7a
