Maria
supports a number of configuration
options to control the operation and performance of the storage
engine. Many of the options are similar to options that are
already available within the MyISAM
configuration options. See
Section 13.4, “The MyISAM
Storage Engine”.
Maria
command options:
maria
enables the Maria
plugin. You can disable Maria
by using
--skip-maria
.
Default is for the Maria
plugin to be
enabled.
You cannot disable Maria
if you have
enabled Maria
as the default engine for
temporary tables using the configure
--with-maria-tmp-tables
option. If
--with-maria-tmp-tables
has been enabled it
will be used for all temporary tables, including
INFORMATION_SCHEMA
tables.
Sets the block size to be used for Maria
index pages and data pages for the new PAGE
row format. Once the page size has been set the first time
mysqld
has been run, you cannot change the
page size without recreating all your Maria
tables.
To change the block size of existing tables, you should use
mysqldump to save a copy of the table
data, cleanly shutdown mysqld, remove the
maria_log_control
file and associated
logs, and reconfigure the block size before starting up
mysqld again.
The configuration setting of this value is recorded within the
maria_log_control
file the first time
MySQL is started with the Maria
engine
enabled.
The default size is 8192 (8KB).
Sets the interval between automatic checkpoints. Checkpoints
in Maria
synchronize the in-memory and
on-disk data and then collate information about the current
status of different transactions, before writing the
information about the current status to the
Maria
log. The use of checkpoints improves
the ability and speed of Maria
when
recovering from a crash, as recovery can continue from the
last stable checkpoint in the log, instead of replaying the
entire log.
The default checkpoint interval is 30 seconds. You can disable checkpoints by setting the value to 0, but disabling checkpoints will increase the time taken to recover in the event of a failure. You should only set the value to 0 during testing.
This parameter was previously known as
maria_check_interval
.
maria-force-start-after-recovery-failures
Sets the maximum number of recovery operations to attempt
before deleting the Maria
log files and
forcing mysqld to start. Recovery of the
Maria
tables using the log files may fail
during startup, preventing mysqld from
starting.
Setting
maria-force-start-after-recovery-failures
to a nonzero value forces Maria
to check
the recovery count within the Maria
log
control file. This value is incremented each time a recovery
is attempted. If the number of attempts matches the value of
maria-force-start-after-recovery-failures
,
then Maria
will delete all the current log
files before mysqld starts.
Because forcing a start without recovery leaves tables in an
inconsistent state, you should only set
maria-force-start-after-recovery-failures
in conjunction with the maria-recovery
option, which forces checking and recovery of tables during
startup without requiring the Maria log files.
The default value is 0.
Setting maria-force-start-after-recovery
may increase the downtime and recovery time, as the recovery
will be attempted a number of times before startup is
forced. However, without it, mysqld will
fail to start up if there are broken tables.
Sets the path to the directory where the transactional log files and the log control file will be stored. You can set this to another device to improve performance.
The default value is to use the same directory as the
datadir
option.
This option is only available through the configuration or command-line. You cannot change the location of the log files while mysqld is running.
Sets the size of each of the Maria
log
files. When the log reaches this figure, a new log file (with
a new sequential log file number) is created, and the
maria_log_control
file is updated.
The default size is 1GB. The minimum log file size is 8MB and the maximum log file size is (4GB - 8192 bytes)
Specifies how the transactional log will be purged. Supported types are as follows:
at_flush
— the logs will be
removed (deleted from disk) only when they have been
marked “free” (that is, there are no pending
transactions), and a
FLUSH
LOGS
statement has been executed.
immediate
— the logs are deleted
as soon as they no longer have pending transactions.
external
— the logs are not
deleted automatically; it is assumed an external utility
is responsible for actually deleting the logs. This can be
used in combination with a backup solution to delete the
logs only once a backup has been completed.
Default is immediate
.
Don't use the fast sort index method to create the index if the temporary file would get bigger than this size.
Default is the maximum file size.
Sets the default mode for page checksums. If a table has page
checksums, then Maria
will use the checksum
to ensure that the page information is not corrupted. You can
override page checksums on a table by table level by using the
PAGE_CHECKSUM
or
CHECKSUM
option during
CREATE TABLE
.
Default is for maria_page_checksum
to be
enabled.
The number of hits that a hot block in the page cache has to be untouched until it is considered old enough to be downgraded to a warm block. Lower values cause demotion to happen more quickly.
The default is 300.
Sets the size of the buffer used for data and index pages to
Maria
tables. You should increase this
value to improve performance on data and index reads and
writes, ideally to the maximum figure supported by your
environment.
The default value is 8MB.
maria_pagecache_division_limit
The minimum percentage of warm blocks in the page cache.
The default value is 100.
Forces recovery of corrupted Maria
tables
without using the log files. Unlike the automatic recovery
supported by Maria
on transactional tables,
maria-recover
will work for all
Maria
tables.
Number of threads to be used when repairing
Maria
tables when using
REPAIR TABLE
. The default value
of 1 disables parallel repair.
Sets the size of the buffer that is allocated when sorting the
index when doing a REPAIR
or when creating
indexes using CREATE INDEX
or
ALTER TABLE
. Increasing this
option will improve the speed of the index creation process.
The default value is 8MB.
Specifies how index statistics collection treats
NULL
values. Valid choices are
nulls_unequal
,
nulls_equal
,
nulls_ignored
.
The default setting is nulls_unequal
.
Controls the synchronization of the directory after a log file
has been extended or a new log file has been created.
Supported values are never
,
newfile
(only when a new log file is
created), and always
.
The default setting is newfile
.
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