Press CTRL+C to copySHOW [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 17, The InnoDB Storage Engine, and Chapter 18, Alternative Storage Engines.
Press CTRL+C to copymysql> SHOW ENGINES\G *************************** 1. row *************************** Engine: ARCHIVE Support: YES Comment: Archive storage engine Transactions: NO XA: NO Savepoints: NO *************************** 2. row *************************** Engine: BLACKHOLE Support: YES Comment: /dev/null storage engine (anything you write to it disappears) Transactions: NO XA: NO Savepoints: NO *************************** 3. row *************************** Engine: MRG_MYISAM Support: YES Comment: Collection of identical MyISAM tables Transactions: NO XA: NO Savepoints: NO *************************** 4. row *************************** Engine: FEDERATED Support: NO Comment: Federated MySQL storage engine Transactions: NULL XA: NULL Savepoints: NULL *************************** 5. row *************************** Engine: MyISAM Support: YES Comment: MyISAM storage engine Transactions: NO XA: NO Savepoints: NO *************************** 6. row *************************** Engine: PERFORMANCE_SCHEMA Support: YES Comment: Performance Schema Transactions: NO XA: NO Savepoints: NO *************************** 7. row *************************** Engine: InnoDB Support: DEFAULT Comment: Supports transactions, row-level locking, and foreign keys Transactions: YES XA: YES Savepoints: YES *************************** 8. row *************************** Engine: MEMORY Support: YES Comment: Hash based, stored in memory, useful for temporary tables Transactions: NO XA: NO Savepoints: NO *************************** 9. row *************************** Engine: CSV Support: YES Comment: CSV storage engine 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 engineNO
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 7.4.2, “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 theengine_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 disableMyISAM
.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 28.3.13, “The INFORMATION_SCHEMA ENGINES Table”.