Changes in MySQL 5.7.9 (2015-10-21, General Availability)
Server Administration
- A new
SHUTDOWN
SQL statement is available. This provides an SQL-level interface to the same functionality previously available using the mysqladmin shutdown command or themysql_shutdown()
C API function. See SHUTDOWN Statement.The
mysql_shutdown()
function and correspondingCOM_SHUTDOWN
client/server protocol command are deprecated and will be removed in a future MySQL version. Instead, usemysql_query()
to execute aSHUTDOWN
statement.
Functionality Added or Changed
- Incompatible Change; InnoDB: To better manage redo log format changes, the redo log header of the first redo log file (
ib_logfile0
) now includes a format version identifier and a text string that identifies the MySQL version that created the redo log files.A new boolean configuration option,
innodb_log_checksums
, replaces theinnodb_log_checksum_algorithm
option.innodb_log_checksums=ON
enables aCRC-32C
checksum, making it the only supported checksum for redo log pages.This patch also removes unused fields from the redo log header and checkpoint pages.
Due to redo log format changes introduced by this patch, upgrading to or downgrading from MySQL 5.7.9 and higher requires a clean shutdown and, in some cases, removal of existing redo log files. For instructions related to this change, see Changes in MySQL 5.7, and Downgrade Notes. (Bug #21759424, Bug #78275, Bug #21752674)
- Important Change; InnoDB:
DYNAMIC
replacesCOMPACT
as the implicit default row format forInnoDB
tables. A new configuration option,innodb_default_row_format
, specifies the defaultInnoDB
row format. Permitted values includeDYNAMIC
(the default),COMPACT
, andREDUNDANT
.The
COMPACT
row format remained the default row format until this release to ensure compatibility with older versions ofInnoDB
in MySQL 5.1 and earlier. Now that MySQL 5.1 has reached the end of its product lifecycle, the newerDYNAMIC
row format becomes the default. For information about advantages of theDYNAMIC
row format, see DYNAMIC Row Format.Newly created tables use the row format defined by
innodb_default_row_format
when aROW_FORMAT
option is not specified explicitly or whenROW_FORMAT=DEFAULT
is used.Existing tables retain their current row format if a
ROW_FORMAT
option was specified explicitly. If aROW_FORMAT
option was not specified explicitly or ifROW_FORMAT=DEFAULT
was used, any operation that rebuilds a table also silently changes the row format of the table to the format defined byinnodb_default_row_format
. For more information, see Defining the Row Format of a Table. - ...
原文地址:https://www.cnblogs.com/jinzhenshui/p/12584145.html