The following is a comparison of variables that either appear only in MariaDB 5.5, or have different default settings in MariaDB 5.5, and MySQL 5.5. MariaDB and MySQL 5.5.38, with only default plugins enabled, were used for the comparison.
The most notable differences are that MariaDB includes, by default, the storage engine, uses , and has a different . For this reason, a default implementation of MariaDB 5.5 will use more memory than MySQL 5.5. This can be handled with the following rules of thumb:
If you are not using and don't plan to use :
Set to something very low (16K) as it's not used.
Set to what you think you need for handling internal tmp tables that didn't fit in memory.
Normally this is what before you had set for (at least 1M).
If you are using and not planning to use :
Set to what you think you need for handling internal tmp tables that didn't fit in memory.
If you are planning to use , you should set to something that fits a big part of your normal data + overflow temporary tables.
The large number of differences between MySQL's and MariaDB's default innodb* variables (based upon InnoDB/XtraDB differences) are not listed here. Details can be found on the page.
0
-
The Aria storage engine is only available in MariaDB
none
-
The Aria storage engine is only available in MariaDB
0
-
The Aria storage engine is only available in MariaDB
1073741824
-
The Aria storage engine is only available in MariaDB
immediate
-
The Aria storage engine is only available in MariaDB
9223372036853727232
-
The Aria storage engine is only available in MariaDB
ON
-
The Aria storage engine is only available in MariaDB
300
-
The Aria storage engine is only available in MariaDB
134217720
-
The Aria storage engine is only available in MariaDB
100
-
The Aria storage engine is only available in MariaDB
NORMAL
-
The Aria storage engine is only available in MariaDB
1
-
The Aria storage engine is only available in MariaDB
134217728
-
The Aria storage engine is only available in MariaDB
nulls-unequal
-
The Aria storage engine is only available in MariaDB
NEWFILE
-
The Aria storage engine is only available in MariaDB
ON
-
The Aria storage engine is only available in MariaDB
OFF
-
Introduced in for between and MySQL/.
NONE
-
Specifies the type of BINLOG_CHECKSUM_ALG for log events in the .
ON
-
For optimized kernel thread scheduling.
15
-
The Aria storage engine is only available in MariaDB
4
-
The Aria storage engine is only available in MariaDB
50000000
-
The Aria storage engine is only available in MariaDB
10000
-
The Aria storage engine is only available in MariaDB
OFF
-
Disable system thread alarm calls, for debugging or testing
OFF
ON
Controlled by
100
-
Used for determining expensive queries for optimization.
1
-
Introduced in the .
0
-
Introduced in the .
-
Comma-delimited list of directories in the data directory that are not considered as database directories. Only introduced in MySQL 5.6
0
-
Set to 1 if you are in a transaction, and 0 if not.
2097152
-
Maximum size in bytes of the query buffer. See .
2
-
For determining the join algorithms. See .
134217728
8388608
Size of the buffer for the index blocks used by MyISAM tables and shared for all threads.
0
-
The number of segments in a key cache. See .
admin, filesort, filesort_on_disk, full_join, full_scan, query_cache, query_cache_miss, tmp_table, tmp_table_on_disk
-
For slow query log filtering.
1
-
Limits the number of queries logged to the .
''
-
Controls information to be added to the . See also .
OFF
-
Verify binlog checksums when reading events from the binlog on the master.
4294967295
4294967295 (32-bit) or 18446744073709547520 (64-bit)
The most key seeks required when searching with an index, regardless of the actual index cardinality. If this value is set lower than its default and maximum, indexes will tend to be preferred over table scans.
4294967295
4294967295 (32-bit) or 18446744073709547520 (64-bit)
Read lock requests will be permitted for processing after this many write locks.
262144
-
Size of buffer to use when using multi-range read with range access. See .
1024
-
Block size used for index pages.
DEFAULT
OFF
MyISAM recovery mode.
new
-
OFF
Used for backward-compatibility with MySQL 4.1, not present in MariaDB
Empty string
-
Used for getting MariaDB to emulate behavior from an old version of MySQL or MariaDB. See .
A series of flags for controlling the query optimizer. MariaDB has introduced a number of new settings.
unknown
-
Minimum acceptable plugin maturity.
5
-
See .
OFF
-
Whether to strip any comments from the query before searching to see if it exists in the .
OFF
-
Tells the slave to reproduce annotate_rows_events received from the master in its own binary log.
empty string
-
See .
empty string
-
See .
replicate
-
See .
empty string
-
See .
empty string
-
See .
empty string
-
See .
empty string
-
See .
8388608
-
See .
OFF
-
See .
ON
-
Verify binlog checksums when the slave SQL thread reads events from the relay log.
60
-
See .
60
-
See .
60
-
Windows-only. See .
3
-
See .
Number of processors
16*
See . *Only available in MySQL with a commercial plugin.
500
6*
See . *Only available in MySQL with a commercial plugin.
294912
196608 or 262144
See .
OFF
-
Whether to activate MariaDB's implementation, not available in MySQL.
Variable
MySQL 5.5
Notes
Variable
MySQL 5.5
Notes
8192
-
The Aria storage engine is only available in MariaDB
30
-
The Aria storage engine is only available in MariaDB
1048576
-
The Aria storage engine is only available in MariaDB