首页 / MYSQL / Mysql:Changes in MySQL 5.7.7 (2015-04-08, Release Candidate):The innodb_file_format default value wa
Mysql:Changes in MySQL 5.7.7 (2015-04-08, Release Candidate):The innodb_file_format default value wa
内容导读
互联网集市收集整理的这篇技术教程文章主要介绍了Mysql:Changes in MySQL 5.7.7 (2015-04-08, Release Candidate):The innodb_file_format default value wa,小编现在分享给大家,供广大互联网技能从业者学习和参考。文章包含7513字,纯文字阅读大概需要11分钟。
内容图文
![Mysql:Changes in MySQL 5.7.7 (2015-04-08, Release Candidate):The innodb_file_format default value wa](/upload/InfoBanner/zyjiaocheng/875/86fbee9842a948968401c0e7c58105bd.jpg)
Changes in MySQL 5.7.7 (2015-04-08, Release Candidate)
Functionality Added or Changed
-
Important Change; InnoDB: The following changes were made to
InnoDB
configuration option default values:-
The innodb_file_format default value was changed to
Barracuda
. The previous default value wasAntelope
. This change allows tables to use Compressed or Dynamic row formats. -
The innodb_large_prefix default value was changed to
ON
. The previous default wasOFF
. When innodb_file_format is set toBarracuda
, innodb_large_prefix=ON allows index key prefixes longer than 767 bytes (up to 3072 bytes) for tables that use a Compressed or Dynamic row format. -
The innodb_strict_mode default value was changed to
ON
. The previous default wasOFF
. When innodb_strict_mode is enabled,InnoDB
raises error conditions in certain cases, rather than issuing a warning and processing the specified statement (perhaps with unintended behavior).
The configuration parameter default changes described above may affect replication and mysqldump operations. Consider the following recommendations when using the new default settings:
-
When replicating or replaying mysqldump data from older MySQL versions to MySQL 5.7.7 or higher, consider setting innodb_strict_mode to
OFF
to avoid errors. Target settings should not be more strict than source settings. -
When replicating from MySQL 5.7.7 or higher to older slaves, consider setting
innodb_file_format=Barracuda
andinnodb_large_prefix=ON
on the slave so that the target and source have the same settings.
The following file format related configuration options are deprecated and will be removed in a future MySQL version:
These four configuration options were provided for creating tables compatible with earlier versions of
InnoDB
in MySQL 5.1. Now that MySQL 5.1 has reached the end of its product lifecycle, these options are no longer required. Also, the file format scheme, by which named file formats would be introduced as new features were added, was not used after introduction of theBarracuda
file format.InnoDB
formats have changed since the introduction of theBarracuda
file format, but new named file formats have not been added.If non-default values are used for any of the four deprecated options,
InnoDB
prints a deprecation and removal warning to the server error log. The same warning is issued to the client if the parameters are set dynamically using a SET statement. -
-
Important Change; InnoDB: The innodb_buffer_pool_dump_at_shutdown and innodb_buffer_pool_load_at_startup configuration options are now enabled by default. With this change, a percentage of most-recently-used buffer pool pages is dumped at server shutdown and restored at server startup. This behavior helps avoid a lengthy buffer pool warmup period after restarting the server, particularly for instances with large buffer pools. The innodb_buffer_pool_dump_pct option defines the percentage of buffer pool pages that are dumped. The default value for innodb_buffer_pool_dump_pct is reduced from 100 to 25.
These configuration option default value changes represent a change in behaviour at server shutdown and startup. If you prefer the previous default values, it is recommended that you configure the options explicitly in your MySQL configuration file after upgrading to MySQL 5.7.7 or later, and before restarting the server.
For more information, see Saving and Restoring the Buffer Pool State.
-
Important Change; InnoDB: The innodb_checksum_algorithm default value is now
crc32
. The previous default setting wasinnodb
. This change also means that innodb_checksums=ON is now equivalent to innodb_checksum_algorithm=crc32 instead of innodb_checksum_algorithm=innodb. -
InnoDB: The
InnoDB
MeCab full-text parser plugin now supports theeucjpms
,cp932
, andutf8mb4
character sets. (Bug #20534096) -
InnoDB: To address a scalability bottleneck for some workloads where
LOCK_grant
is locked in read-mode,LOCK_grant
locks are now partitioned. Read lock requests onLOCK_grant
now acquire one of multipleLOCK_grant
partitions. Write locks must acquire all partitions.To address another scalability bottleneck, the server no longer performs unnecessary lock acquisitions when creating interal temporary tables.
References: See also: Bug #72829, Bug #20023139.
-
Replication: The defaults of some replication related variables have been modified. The following changes have been made:
Additionally, the session scope of gtid_executed has been deprecated. The global scope of gtid_executed remains supported.
-
Replication: The XA implementation in MySQL has been made much more compatible with the XA specification. A prepared XA transaction is no longer rolled back at disconnect. Now when replicating using the binary log, an XA transaction in
PREPARED
state persists in the binary log until an explicitXA COMMIT
orXA ROLLBACK
statement is issued. In prior versions, an XA transaction that was inPREPARED
state would be rolled back on clean server shutdown or client disconnect. Similarly, an XA transaction that was inPREPARED
state would still exist inPREPARED
state in case the server was shut down abnormally and then started again, but the contents of the transaction could not be written to the binary log. As part of this feature, a new event,XA_prepare_log_event
, has been added to track XA transactions in thePREPARED
state and enable them to be replicated. To finalize a two-phase XA transaction, theXA COMMIT
orXA ROLLBACK
is recorded separately in the binary log, possibly interleaving with other transactions. XA transactions committed with the newXA COMMIT ONE PHASE
syntax are logged as one part usingXA_prepare_log_event
.References: See also: Bug #12161, Bug #11745231, Bug #75204, Bug #20214365.
-
Performance Schema stage event instruments that provide statement progress information now are enabled and timed by default. The affected instruments are those displayed by this statement:
SELECT * FROM performance_schema.setup_instruments WHERE ENABLED='YES' AND NAME LIKE "stage/%";
(Bug #20685859)
-
The
XID
column of Performance Schema transaction tables (for example, events_transactions_current) has been split into three columns to permit access to the component parts of XID values. The new columns areXID_FORMAT_ID
,XID_GTRID
, andXID_BQUAL
. (Bug #18320361) -
In MySQL 5.7.6, the NO_AUTO_CREATE_USER was deprecated. (It is preferable to create MySQL accounts with CREATE USER rather than GRANT.) Now the default SQL mode includes NO_AUTO_CREATE_USER and assignments to sql_mode that change the NO_AUTO_CREATE_USER mode state produce a warning, except assignments that set sql_mode to
DEFAULT
. NO_AUTO_CREATE_USER will be removed in a future MySQL version, at which point its effect will be enabled at all times (GRANT will not create accounts). -
Previously, view definitions were not permitted to contain derived tables (subqueries) in the
FROM
clause. This restriction has now been lifted.Previously, derived tables (subqueries) or views in the
FROM
clause could not be merged into the outer query if they contained subqueries in theSELECT
list. Instead, they were processed using materialization. This restriction has now been lifted so that queries previously executed using materialization can be executed more quickly using merging. (Bug #12755, Bug #11745276, Bug #60417, Bug #11865600)
内容总结
以上是互联网集市为您收集整理的Mysql:Changes in MySQL 5.7.7 (2015-04-08, Release Candidate):The innodb_file_format default value wa全部内容,希望文章能够帮你解决Mysql:Changes in MySQL 5.7.7 (2015-04-08, Release Candidate):The innodb_file_format default value wa所遇到的程序开发问题。 如果觉得互联网集市技术教程内容还不错,欢迎将互联网集市网站推荐给程序员好友。
内容备注
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 gblab@vip.qq.com 举报,一经查实,本站将立刻删除。
内容手机端
扫描二维码推送至手机访问。