MySQL 5.1.41 がリリースされました。

このバージョンに含まれている InnoDB Plugin 1.0.5 が ついに RC (Release Candidate)になりました！
GAになるのが楽しみですね。
InnoDB Plugin が 従来の組込型 InnoDB と比べて何が優れているのかについては、
サンマイクロシステムズ松信氏の以下のエントリに詳しいです。
http://opendatabaselife.blogspot.com/2009/08/innodb-plugin-104-innodb.html

　(追記）InnoDB のバッファプール管理について、組込InnoDB と InnoDB Plugin の動作の違い（Plugin 化されて進化した部分）を sh2氏が非常にわかりやすくまとめています。
http://d.hatena.ne.jp/sh2/20091120



ダウンロードはこちらから。
http://dev.mysql.com/downloads/mysql/5.1.html

----------------------
　以下チェンジログ




■機能の追加と変更(5.1.41)：
* In the default operation of the InnoDB buffer pool, a block is
loaded at the midpoint for the first access and then moved
immediately to the head of the list as soon as another access
occurs. In the case of a table scan (such as performed for a
mysqldump operation), each block read by the scan ends up
moving to the head of the list because multiple rows are
accessed from each block. This occurs even for a one-time
scan, where the blocks are not otherwise used by other
queries. Blocks may also be loaded by the read-ahead
background thread and then moved to the head of the new
sublist by a single access. These effects are disadvantageous
because they push blocks that are in heavy use by other
queries out of the new sublist to the old sublist where they
become subject to eviction.
InnoDB Plugin now provides two system variables that enable
LRU algorithm tuning:

+ innodb_old_blocks_pct
Specifies the approximate percentage of the buffer pool
used for the old block sublist. The range of values is 5
to 95. The default value is 37 (that is, 3/8 of the
pool).

+ innodb_old_blocks_time
Specifies how long in milliseconds (ms) a block inserted
into the old sublist must stay there before it can be
moved to the new sublist. The default value is 0, so
after a block is inserted into the old sublist, it moves
immediately to the new sublist the next time it is
accessed, no matter how soon after insertion the next
access occurs. If the value is greater than 0, blocks
remain in the old sublist until an access occurs at least
that many ms after initial insertion. For example, a
value of 1000 causes blocks to stay in the old sublist
for 1 second before moving to the new sublist.
For additional information, see Section 7.4.6, "The InnoDB
Buffer Pool." (Bug#45015: http://bugs.mysql.com/45015)

* For InnoDB Plugin, two new status variables have been added to
SHOW STATUS output. Innodb_buffer_pool_read_ahead and
Innodb_buffer_pool_read_ahead_evicted indicate the number of
pages read in by the InnoDB read-ahead background thread, and
the number of such pages evicted without ever being accessed,
respectively. Also, the status variables
Innodb_buffer_pool_read_ahead_rnd and
Innodb_buffer_pool_read_ahead_seq status variables have been
removed.
The built-in version of InnoDB is not affected by these
changes. (Bug#42885: http://bugs.mysql.com/42885)

* InnoDB Plugin has been upgraded to version 1.0.5. This version
is considered of Release Candidate (RC) quality.

* The server now supports a Debug Sync facility for thread
synchronization during testing and debugging. To compile in
this facility, configure MySQL with the --enable-debug-sync
option. The debug_sync system variable provides the user
interface Debug Sync. mysqld and mysql-test-run.pl support a
--debug-sync-timeout option to enable the facility and set the
default synchronization point timeout.


■バグ修正(5.1.41)：
* Partitioning: An ALTER TABLE ... ADD PARTITION statement that
caused open_files_limit to be exceeded led to a crash of the
MySQL server. (Bug#46922: http://bugs.mysql.com/46922)
See also Bug#47343: http://bugs.mysql.com/47343.

* Partitioning: The cardinality of indexes on partitioned tables
was calculated using the first partition in the table, which
could result in suboptimal query execution plans being chosen.
Now the partition having the most records is used instead,
which should result in better use of indexes and thus improved
performance of queries against partitioned tables in many if
not most cases. (Bug#44059: http://bugs.mysql.com/44059)

* Replication: When using statement-based or mixed-format
replication, the database name was not written to the binary
log when executing a LOAD DATA statement. This caused problems
when the table being loaded belonged to a database other than
the current database; data could be loaded into the wrong
table (if a table having the same name existed in the current
database) or replication could fail (if no table having that
name existed in the current database). Now a table referenced
in a LOAD DATA statement is always logged using its fully
qualified name when the database to which it belongs is not
the current database.
This issue occurred in MySQL 5.1.40 only.
(Bug#48297: http://bugs.mysql.com/48297)

* Replication: When a session was closed on the master,
temporary tables belonging to that session were logged with
the wrong database names when either of the following
conditions was true:

1. The length of the name of the database to which the
temporary table belonged was greater than the length of
the current database name.

2. The current database was not set.
(Bug#48216: http://bugs.mysql.com/48216)
See also Bug#46861: http://bugs.mysql.com/46861,
Bug#48297: http://bugs.mysql.com/48297.

* Replication: When using row-based replication, changes to
non-transactional tables that occurred early in a transaction
were not immediately flushed upon committing a statement. This
behavior could break consistency since changes made to
non-transactional tables become immediately visible to other
connections. (Bug#47678: http://bugs.mysql.com/47678)
See also Bug#47287: http://bugs.mysql.com/47287,
Bug#46864: http://bugs.mysql.com/46864,
Bug#43929: http://bugs.mysql.com/43929,
Bug#46129: http://bugs.mysql.com/46129.

* Replication: When mysqlbinlog --verbose was used to read a
binary log that had been recorded using the row-based format,
the output for events that updated some but not all columns of
tables was not correct.
(Bug#47323: http://bugs.mysql.com/47323)

* Replication: When using the row-based format to replicate a
transaction involving both transactional and non-transactional
engines, which contained a DML statement affecting multiple
rows, the statement failed; if this transaction was followed
by a COMMIT, the master and the slave could diverge, because
the statement was correctly rolled back on the master, but was
applied on the slave. (Bug#47287: http://bugs.mysql.com/47287)
See also Bug#46864: http://bugs.mysql.com/46864.

* Replication: A problem with the BINLOG statement in the output
of mysqlbinlog could break replication; statements could be
logged with the server ID stored within events by the BINLOG
statement rather than the ID of the running server. With this
fix, the server ID of the server executing the statements can
no longer be overridden by the server ID stored in the binary
log's format description statement.
(Bug#46640: http://bugs.mysql.com/46640)
This regression was introduced by
Bug#32407: http://bugs.mysql.com/32407.

* Replication: When using statement-based replication and the
transaction isolation level was set to READ COMMITTED or a
less strict level, InnoDB returned an error even if the
statement in question was filtered out according to the
--binlog-do-db or --binlog-ignore-db rules in effect at the
time. (Bug#42829: http://bugs.mysql.com/42829)

* Replication: FLUSH LOGS did not actually close and reopen the
binary log index file.
(Bug#34582: http://bugs.mysql.com/34582)

* A build configured using the --without-server option did not
compile the yaSSL code, so if --with-ssl was also used, the
build failed. (Bug#47957: http://bugs.mysql.com/47957)

* mysys/mf_keycache.c requires threading, but no test was made
for thread support. (Bug#47923: http://bugs.mysql.com/47923)

* The mysys/mf_strip.c file, which defines the strip_sp has been
removed from the MySQL source. The function was no longer in
use within the main build, and the supplied function was
causing symbol errors on Windows builds.
(Bug#47857: http://bugs.mysql.com/47857)

* The Windows build for MySQL would compile the split.c and
debug.c files unnecessarily, causing additional symbols to be
included in mysqld. (Bug#47850: http://bugs.mysql.com/47850)

* When building storage engines on Windows it was not possible
to specify additional libraries within the CMake file required
for the build. An ${engine}_LIBS macro has been added to the
files to support these additional storage-engine specific
libraries. (Bug#47797: http://bugs.mysql.com/47797)

* When building a pluggable storage engine on Windows, the
engine name could be based on the directory name where the
engine was located, rather than the configured storage engine
name. (Bug#47795: http://bugs.mysql.com/47795)

* On Windows, when an idle named pipe connection was forcibly
closed with a KILL statement or because the server was being
shut down, the thread that was closing the connection would
hang infinitely. (Bug#47571: http://bugs.mysql.com/47571,
Bug#31621: http://bugs.mysql.com/31621)

* A simple SELECT with implicit grouping could return many rows
rather than a single row if the query was ordered by the
aggregated column in the select list.
(Bug#47280: http://bugs.mysql.com/47280)

* An assertion could be raised for CREATE TABLE if there was a
pending INSERT DELAYED or REPLACE DELAYED for the same table.
(Bug#47274: http://bugs.mysql.com/47274)

* Incorrect handling of predicates involving NULL by the range
optimizer could lead to to an infinite loop during query
execution. (Bug#47123: http://bugs.mysql.com/47123)

* Repair by sort or parallel repair of MyISAM tables could fail
to fail over to repair with key cache.
(Bug#47073: http://bugs.mysql.com/47073)

* If InnoDB reached its limit on the number of concurrent
transactions (1023), it wrote a descriptive message to the
error log but returned a misleading error message to the
client, or an assertion failure occurred.
(Bug#46672: http://bugs.mysql.com/46672)
See also Bug#18828: http://bugs.mysql.com/18828.

* Concurrent INSERT INTO ... SELECT statements for an InnoDB
table could cause an AUTO_INCREMENT assertion failure.
(Bug#46650: http://bugs.mysql.com/46650)

* Trailing spaces were not ignored for user-defined collations
that mapped spaces to a character other than 0x20.
(Bug#46448: http://bugs.mysql.com/46448)
See also Bug#29468: http://bugs.mysql.com/29468.

* The GPL and commercial license headers had different sizes, so
that error log, backtrace, core dump, and cluster trace file
line numbers could be off by one if they were not checked
against the version of the source used for the build. (For
example, checking a GPL build backtrace against commercial
sources.) (Bug#46216: http://bugs.mysql.com/46216)

* InnoDB did not disallow creation of an index with the name
GEN_CLUST_INDEX, which is used internally.
(Bug#46000: http://bugs.mysql.com/46000)

* During the build of the Red Hat IA64 MySQL server RPM, the
system library link order was incorrect. This made the
resulting Red Hat IA64 RPM depend on
"libc.so.6.1(GLIBC_PRIVATE)(64bit)", thus preventing
installation of the package.
(Bug#45706: http://bugs.mysql.com/45706)

* With InnoDB Plugin, renaming a table column and then creating
an index on the renamed column caused a server crash to to the
.frm file and the InnoDB data directory going out of sync. Now
InnoDB Plugin 1.0.5 returns an error instead: ERROR 1034
(HY000): Incorrect key file for table 'tbl_name'; try to
repair it. To work around the problem, create another table
with the same structure and copy the original table to it.
(Bug#44571: http://bugs.mysql.com/44571)

* An InnoDB error message incorrectly referred to the
nonexistent innodb_max_files_open variable rather than to
innodb_open_files. (Bug#44338: http://bugs.mysql.com/44338)

* The FORCE INDEX FOR ORDER BY index hint was ignored when join
buffering was used. (Bug#43029: http://bugs.mysql.com/43029)

* Incorrect handling of range predicates combined with OR
operators could yield incorrect results.
(Bug#42846: http://bugs.mysql.com/42846)

* Failure to treat BIT values as unsigned could lead to
unpredictable results.
(Bug#42803: http://bugs.mysql.com/42803)

* Previously, InnoDB performed REPLACE INTO T SELECT ... FROM S
WHERE ... by setting shared next-key locks on rows from S. Now
InnoDB selects rows from from S with shared locks or as a
consistent read, as for INSERT ... SELECT. This reduces lock
contention between sessions.
(Bug#37232: http://bugs.mysql.com/37232)

* When an InnoDB tablespace filled up, an error was logged to
the client, but not to the error log. Also, the error message
was misleading and did not indicate the real source of the
problem. (Bug#31183: http://bugs.mysql.com/31183)

* In mysql, using Control-C to kill the current query resulted
in a ERROR 1053 (08S01): Server shutdown in progress" message
if the query was waiting for a lock.
(Bug#28141: http://bugs.mysql.com/28141)