MySQL 5.6 Reference Manual Including MySQL NDB Cluster 7.3-7.4 Reference Guide
SHOW [STORAGE] ENGINES
SHOW ENGINES
displays status
information about the server's storage engines. This is
particularly useful for checking whether a storage engine is
supported, or to see what the default engine is.
For information about MySQL storage engines, see Chapter 14, The InnoDB Storage Engine, and Chapter 15, Alternative Storage Engines.
mysql> SHOW ENGINES\G
*************************** 1. row ***************************
Engine: FEDERATED
Support: NO
Comment: Federated MySQL storage engine
Transactions: NULL
XA: NULL
Savepoints: NULL
*************************** 2. row ***************************
Engine: MRG_MYISAM
Support: YES
Comment: Collection of identical MyISAM tables
Transactions: NO
XA: NO
Savepoints: NO
*************************** 3. row ***************************
Engine: MyISAM
Support: YES
Comment: MyISAM storage engine
Transactions: NO
XA: NO
Savepoints: NO
*************************** 4. row ***************************
Engine: BLACKHOLE
Support: YES
Comment: /dev/null storage engine (anything you write to it disappears)
Transactions: NO
XA: NO
Savepoints: NO
*************************** 5. row ***************************
Engine: CSV
Support: YES
Comment: CSV storage engine
Transactions: NO
XA: NO
Savepoints: NO
*************************** 6. row ***************************
Engine: MEMORY
Support: YES
Comment: Hash based, stored in memory, useful for temporary tables
Transactions: NO
XA: NO
Savepoints: NO
*************************** 7. row ***************************
Engine: ARCHIVE
Support: YES
Comment: Archive storage engine
Transactions: NO
XA: NO
Savepoints: NO
*************************** 8. row ***************************
Engine: InnoDB
Support: DEFAULT
Comment: Supports transactions, row-level locking, and foreign keys
Transactions: YES
XA: YES
Savepoints: YES
*************************** 9. row ***************************
Engine: PERFORMANCE_SCHEMA
Support: YES
Comment: Performance Schema
Transactions: NO
XA: NO
Savepoints: NO
The output from SHOW ENGINES
may
vary according to the MySQL version used and other factors.
SHOW ENGINES
output has these
columns:
Engine
The name of the storage engine.
Support
The server's level of support for the storage engine, as shown in the following table.
Value | Meaning |
---|---|
YES |
The engine is supported and is active |
DEFAULT |
Like YES , plus this is the default engine |
NO |
The engine is not supported |
DISABLED |
The engine is supported but has been disabled |
A value of NO
means that the server was
compiled without support for the engine, so it cannot be
enabled at runtime.
A value of DISABLED
occurs either because
the server was started with an option that disables the
engine, or because not all options required to enable it
were given. In the latter case, the error log should contain
a reason indicating why the option is disabled. See
Section 5.4.2, “The Error Log”.
You might also see DISABLED
for a storage
engine if the server was compiled to support it, but was
started with a
--skip-
option. For the engine_name
NDB
storage
engine, DISABLED
means the server was
compiled with support for NDB Cluster, but was not started
with the --ndbcluster
option.
All MySQL servers support MyISAM
tables.
It is not possible to disable MyISAM
.
Comment
A brief description of the storage engine.
Transactions
Whether the storage engine supports transactions.
XA
Whether the storage engine supports XA transactions.
Savepoints
Whether the storage engine supports savepoints.
Storage engine information is also available from the
INFORMATION_SCHEMA
ENGINES
table. See
Section 21.7, “The INFORMATION_SCHEMA ENGINES Table”.