detector". This patch addresses performance regression in OLTP_RO/MyISAM
test on Windows introduced by the fix for bug #56405. Thus it makes
original patch acceptable as a solution for bug #56585 "Slowdown of
readonly sysbench benchmarks (e.g point_select) on Windows 5.5".
With this patch, MySQL will use native Windows condition variables and
reader-writer locks if they are supported by the OS.
This speeds up MyISAM and the effect comes mostly from using native
rwlocks. Native conditions improve scalability with higher number of
concurrent users in other situations, e.g for prlocks.
Benchmark numbers for this patch as measured on Win2008R2 quad
core machine are attached to the bug report.
( direct link http://bugs.mysql.com/file.php?id=15883 )
Note that currently we require at least Windows7/WS2008R2 for
reader-writer locks, even though native rwlock is available also on Vista.
Reason is that "trylock" APIs are missing on Vista, and trylock is used in
the server (in a single place in query cache).
While this patch could have been written differently, to enable the native
rwlock optimization also on Vista/WS2008 (e.g using native locks everywhere
but portable implementation in query cache), this would come at the
expense of the code clarity, as it would introduce a new "try-able" rwlock
type, to handle Vista case.
Another way to improve performance for the special case
(OLTP_RO/MYISAM/Vista) would be to eliminate "trylock" usage from server,
but this is outside of the scope here.
Native conditions variables are used beginning with Vista though the effect
of using condition variables alone is not measurable in this benchmark.
But when used together with native rwlocks on Win7, native conditions improve
performance in high-concurrency OLTP_RO/MyISAM (128 and more sysbench
users).
This assert was triggered if DELETE was done on a view that
referenced another view which in turn (directly or indirectly)
referenced more than one table.
Delete from a view referencing more than one table (a join view)
is not supported and is supposed to give ER_VIEW_DELETE_MERGE_VIEW
error. Before this error was reported from the multi table
delete code, an assert verified that the view from the DELETE statement
had more than one underlying table. However, this assert did not take
into account that the view could refer to another view which in turn
referenced the actual tables.
This patch fixes the problem by adjusting the assert to take this
possibility into account. This problem was only noticeable on debug
builds of the server. On release builds, ER_VIEW_DELETE_MERGE_VIEW
was correctly reported.
Test case added to delete.test.
tcmalloc lib (libtcmalloc_minimal.so) is missing from mysql 5.5 binary
Ensure that a "-DMALLOC_LIB=/foo/bar/libtcmalloc_minimal.so"
will ensure that this library gets included in the tar.gz
binary package.
It depends on the build environment to set this variable
to the correct path name, if it is available.
This is a manual merge from mysql-5.1-innodb of:
revision-id: vasil.dimov@oracle.com-20100930102618-s9f9ytbytr3eqw9h
committer: Vasil Dimov <vasil.dimov@oracle.com>
timestamp: Thu 2010-09-30 13:26:18 +0300
message:
Fix a potential bug when using __sync_lock_test_and_set()
TYPE __sync_lock_test_and_set (TYPE *ptr, TYPE value, ...)
it is not documented what happens if the two arguments are of different
type like it was before: the first one was lock_word_t (byte) and the
second one was 1 or 0 (int).
Approved by: Marko (via IRC)
LOAD DATA into partitioned MyISAM table
Problem was that both partitioning and myisam
used the same table_share->mutex for different protections
(auto inc and repair).
Solved by adding a specific mutex for the partitioning
auto_increment.
Also adding destroying the ha_data structure in
free_table_share (which is to be propagated
into 5.5).
This is a 5.1 ONLY patch, already fixed in 5.5+.
REBUILD PARTITION under LOCK TABLE
Collapsed patch including updates from the reviews.
In case of failure in ALTER ... PARTITION under LOCK TABLE
the server could crash, due to it had modified the locked
table object, which was not reverted in case of failure,
resulting in a bad table definition used after the failed
command.
Solved by instead of altering the locked table object and
its partition_info struct, creating an internal temporary
intermediate table object used for altering,
just like the non partitioned mysql_alter_table.
So if an error occur before the alter operation is complete,
the original table is not modified at all.
But if the alter operation have succeeded so far that it
must be completed as whole,
the table is properly closed and reopened.
(The completion on failure is done by the ddl_log.)
This is a manual merge from mysql-5.1-innodb of:
revno: 3618
revision-id: vasil.dimov@oracle.com-20100930124844-yglojy7c3vaji6dx
parent: vasil.dimov@oracle.com-20100930102618-s9f9ytbytr3eqw9h
committer: Vasil Dimov <vasil.dimov@oracle.com>
branch nick: mysql-5.1-innodb
timestamp: Thu 2010-09-30 15:48:44 +0300
message:
Fix Bug#56340 innodb updates index stats too frequently after non-index updates
This is a simple optimization issue. All stats are related to only indexed
columns, index size or number of rows in the whole table. UPDATEs that touch
only non-indexed columns cannot affect stats and we can avoid calling the
function row_update_statistics_if_needed() which may result in unnecessary I/O.
Approved by: Marko (rb://466)
In addition to the above message: we know that
row_update_cascade_for_mysql() (the other place where
row_update_statistics_if_needed is called) always updates indexed
columns (FK-related), so there is no need to add this cond there.
Bug#57113: ha_partition::extra(ha_extra_function):
Assertion `m_extra_cache' failed
Fix for bug#55458 included DBUG_ASSERTS causing
debug builds of the server to crash on
another multi-table update.
Removed the asserts since they where wrong.
(updated after testing the patch in 5.5).
This is a simple optimization issue. All stats are related to only indexed
columns, index size or number of rows in the whole table. UPDATEs that touch
only non-indexed columns cannot affect stats and we can avoid calling the
function row_update_statistics_if_needed() which may result in unnecessary I/O.
Approved by: Marko (rb://466)
