The following is a comparison of variables that either appear only in MariaDB 10.0 or MySQL 5.6, or have different default settings in MariaDB 10.0, and MySQL 5.6. MariaDB 10.0.12 and MySQL 5.6.20, with only default plugins enabled, were used for the comparison.
The most notable differences are that MariaDB includes, by default, the storage engine (resulting in extra memory allocation), uses , and has a different . For this reason, a default implementation of MariaDB 10.0 will use more memory than MySQL 5.6. MariaDB 10 and MySQL 5.6 also have different .
MariaDB's extra memory usage 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.
NONE
CRC32
Specifies the type of BINLOG_CHECKSUM_ALG for log events in the .
0
-
For use in MariaDB's .
100000
-
For use in MariaDB's .
binlog_max_flush_queue_time
-
0
MySQL 5.6-only variable specifying a timeout for reading transactions from the flush queue before continuing with group commit and syncing log to disk.
ON
-
For optimized kernel thread scheduling.
binlog_order_commits
-
ON
MySQL 5.6-only variable for determining whether transactions may be committed in parallel.
binlog_row_image
-
ON
MySQL 5.6-only variable permitting partial logging.
binlog_rows_query_log_events
-
OFF
MySQL 5.6-only variable for logging extra information in row-based logging.
binlogging_impossible_mode
-
IGNORE_ERROR
MySQL 5.6-only variable, determines what happens if a write to binlog fails.
block_encryption_mode
-
aes-128-ecb
MySQL 5.6-only variable for controlling the block encryption mode for block-based algorithms.
core_file
-
OFF
MySQL 5.6-only variable indicating whether a core file will be written in case of a crash.
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
empty
-
For use with MariaDB's .
empty
-
For handling incompatibilities between MariaDB's and the old regex library.
-
InnoDB
Available from
disconnect_on_expired_password
-
ON
MySQL 5.6 permits passwords to be expired.
end_markers_in_json
-
OFF
MySQL 5.6-only variable for adding end markers to JSON output
enforce_gtid_consistency
-
OFF
MariaDB and MySQL have different .
eq_range_index_dive_limit
-
10
MySQL 5.6-only variable for tuning when the optimizer should switch from using index dives to index statistics for qualifying rows estimation.
100
-
Used for determining expensive queries for optimization.
explicit_defaults_for_timestamp
-
FALSE
MySQL 5.6-only variable for handling TIMESTAMP defaults in a standard way.
1
-
Introduced in the .
0
-
Introduced in the .
empty
-
MariaDB and MySQL have different .
empty
-
MariaDB and MySQL have different .
empty
-
MariaDB and MySQL have different .
0
-
MariaDB and MySQL have different .
gtid_executed
-
empty
MariaDB and MySQL have different .
OFF
-
MariaDB and MySQL have different .
gtid_mode
-
OFF
MariaDB and MySQL have different .
gtid_next
-
AUTOMATIC
MariaDB and MySQL have different .
gtid_owned
-
empty
MariaDB and MySQL have different .
gtid_purged
-
empty
MariaDB and MySQL have different .
0
-
MariaDB and MySQL have different .
empty
-
MariaDB and MySQL have different .
OFF
-
MariaDB and MySQL have different .
MariaDB's version indicates whether YaSSL or openssl was used. MySQL's is a synonym for have_ssl.
0
-
MariaDB introduced .
SINGLE_PREC_HB
-
MariaDB introduced .
128
279 (autosized)
MySQL increments the value based on the size of .
0
-
Set to 1 if you are in a transaction, and 0 if not.
*
*
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.
131072 (128KB)
262144 (256KB)
Minimum size of the buffer used for queries that cannot use an index, and instead perform a full table scan. MariaDB's default is sufficient for most users.
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 .
-
empty
MariaDB and MySQL have different .
log_bin_basename
-
empty
MySQL-only variable containing the complete path to the binary log file.
log_bin_index
-
empty
MySQL-only variable containing the index file for binary log file names.
log_bin_use_v1_row_events
-
OFF
MySQL-only variable showing whether or not MySQL's version 2 binary logging format is being used.
log_slow_admin_statements
-
OFF
MySQL-only variable determining whether or not to include slow admin statements in the slow query log.
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 .
log_slow_slave_statements
-
OFF
MySQL-only variable determining whether or not to include slow slave statements in the slow query log.
empty
-
Controls information to be added to the . See also .
log_throttle_queries_not_using_indexes
-
0
MySQL-only variable for limiting the number of statements without indexes written to the slow query log.
master_info_repository
-
FILE
MySQL-only variable determining whether the slaves log info to file or table.
1048576
4194304
Maximum size in bytes of a packet or a generated/intermediate string. Increased in MySQL 5.6.6 to 4MB.
1048576
-
Maximum size for parameter values sent with mysql_stmt_send_long_data(). Removed in MySQL 5.6.
1073741824
0
Can be set by session in MariaDB.
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.
134216704
8388608
Size in bytes of the buffer allocated when creating or sorting indexes on a MyISAM table.
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 .
100
-
Controls number of record samples to check condition selectivity.
A series of flags for controlling the query optimizer. MariaDB has introduced a number of new settings.
optimizer_trace
-
Off by default
MySQL 5.6-only variable for optimizer tracing.
optimizer_trace_features
-
Off by default
MySQL 5.6-only variable for optimizer tracing.
optimizer_trace_limit
-
1
MySQL 5.6-only variable for optimizer tracing.
optimizer_trace_max_mem_size
-
16384
MySQL 5.6-only variable for optimizer tracing.
optimizer_trace_offset
-
-1
MySQL 5.6-only variable for optimizer tracing.
1
-
Controls which statistics can be used by the optimizer when looking for the best query execution plan.
OFF
ON
The is off by default in MariaDB.
Many performance schema variables are autoset in MySQL.
unknown
-
Minimum acceptable plugin maturity.
5
-
Time in seconds between sending progress reports to the client for time-consuming statements.
0
1048576
MySQL and MariaDB disable the query cache by default in different manners.
OFF
-
Whether to strip any comments from the query before searching to see if it exists in the .
ON
OFF
MySQL and MariaDB disable the query cache by default in different manners.
relay_log_basename
-
empty
MySQL-only variable containing the complete path to the relay log file.
relay_log_info_repository
-
FILE
MySQL-only variable determining whether the slave's position in the relay logs is written to a file or table.
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 .
0
-
Unused, removed in MySQL 5.6.
rpl_stop_slave_timeout
-
31536000
MySQL-only variable for controlling the time that STOP SLAVE waits before timing out.
OFF
ON
MySQL 5.6 prohibits connections from clients using the old (pre-MySQL 4.1) password format.
server_id_bits
-
server_id
MySQL-only variable for use in MySQL Cluster.
server_uuid
-
UUID
MySQL-only variable containing the UUID.
OFF
-
See .
slave_allow_batching
-
OFF
MySQL-only replication variable.
slave_checkpoint_group
-
512
MySQL-only replication variable.
slave_checkpoint_period
-
300
MySQL-only replication variable.
IDEMPOTENT
-
Modes for how replication of DDL events should be executed.
0
-
For configuring .
131072
-
For configuring .
0
-
For configuring .
slave_parallel_workers
-
0
MySQL-only replication variable.
slave_pending_jobs_size_max
-
16777216
MySQL-only replication variable.
slave_rows_search_algorithms
-
TABLE_SCAN, INDEX_SCAN
MySQL-only replication variable.
2097152
262144
The default sort buffer allocated has been reduced in MySQL.
empty
NO_ENGINE_SUBSTITUTION
MySQL 5.6 does not permit tables to be created in the default storage engine if the original is not available. See .
0
10000
MariaDB relies upon the operating system to flush the master.info file to disk.
0
10000
MariaDB relies upon the operating system to flush the relay log to disk.
0
10000
MariaDB relies upon the operating system to flush the relay-log.info file to disk.
400
-1 (autosized)
Number of table definitions that can be cached.
400
-1 (autosized)
Number of open tables for all threads. See .
-
1
Removed in MariaDB as similar results achieved in a different way.
0
-1 (autosized)
MariaDB uses an .
60
-
See .
500
-
See .
1
-
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 .
transaction_allow_batching
-
OFF
MySQL-only variable for enabling batching of statements within the same transaction in MySQL Cluster.
NEVER
-
Controls the use of .
OFF
-
Whether to activate MariaDB's implementation, not available in MySQL.
bundled_jemalloc
-
Version of the used malloc library.
Variable
MySQL 5.6
Notes
Variable
MySQL 5.6
Notes
*
-
The storage engine is only available in MariaDB.
-
127.0.0.1
MySQL has the value of the bind-address option as a variable.
OFF
-
Introduced in MariaDB 5.3 for replicating between MariaDB 5.3 and MySQL/MariaDB 5.1.