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13.7.6.16 SHOW ENGINES Syntax

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  1. 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 15, The InnoDB Storage Engine, and Chapter 16, Alternative Storage Engines.

  1. mysql> SHOW ENGINES\G
  2. *************************** 1. row ***************************
  3.       Engine: ARCHIVE
  4.      Support: YES
  5.      Comment: Archive storage engine
  6. Transactions: NO
  7.           XA: NO
  8.   Savepoints: NO
  9. *************************** 2. row ***************************
  10.       Engine: BLACKHOLE
  11.      Support: YES
  12.      Comment: /dev/null storage engine (anything you write to it disappears)
  13. Transactions: NO
  14.           XA: NO
  15.   Savepoints: NO
  16. *************************** 3. row ***************************
  17.       Engine: MRG_MYISAM
  18.      Support: YES
  19.      Comment: Collection of identical MyISAM tables
  20. Transactions: NO
  21.           XA: NO
  22.   Savepoints: NO
  23. *************************** 4. row ***************************
  24.       Engine: FEDERATED
  25.      Support: NO
  26.      Comment: Federated MySQL storage engine
  27. Transactions: NULL
  28.           XA: NULL
  29.   Savepoints: NULL
  30. *************************** 5. row ***************************
  31.       Engine: MyISAM
  32.      Support: YES
  33.      Comment: MyISAM storage engine
  34. Transactions: NO
  35.           XA: NO
  36.   Savepoints: NO
  37. *************************** 6. row ***************************
  38.       Engine: PERFORMANCE_SCHEMA
  39.      Support: YES
  40.      Comment: Performance Schema
  41. Transactions: NO
  42.           XA: NO
  43.   Savepoints: NO
  44. *************************** 7. row ***************************
  45.       Engine: InnoDB
  46.      Support: DEFAULT
  47.      Comment: Supports transactions, row-level locking, and foreign keys
  48. Transactions: YES
  49.           XA: YES
  50.   Savepoints: YES
  51. *************************** 8. row ***************************
  52.       Engine: MEMORY
  53.      Support: YES
  54.      Comment: Hash based, stored in memory, useful for temporary tables
  55. Transactions: NO
  56.           XA: NO
  57.   Savepoints: NO
  58. *************************** 9. row ***************************
  59.       Engine: CSV
  60.      Support: YES
  61.      Comment: CSV storage engine
  62. Transactions: NO
  63.           XA: NO
  64.   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-engine_name option. For the 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 25.9, “The INFORMATION_SCHEMA ENGINES Table”.


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Document created the 26/06/2006, last modified the 26/10/2018
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