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13.7.5.24 SHOW OPEN TABLES Statement

SHOW OPEN TABLES    [{FROM | IN}db_name]    [LIKE 'pattern' | WHEREexpr]

SHOW OPEN TABLES lists the non-TEMPORARY tables that are currently open in the table cache. SeeSection 8.4.3.1, “How MySQL Opens and Closes Tables”. TheFROM clause, if present, restricts the tables shown to those present in thedb_name database. TheLIKE clause, if present, indicates which table names to match. TheWHERE clause can be given to select rows using more general conditions, as discussed inSection 24.8, “Extensions to SHOW Statements”.

SHOW OPEN TABLES output has these columns:

  • Database

    The database containing the table.

  • Table

    The table name.

  • In_use

    The number of table locks or lock requests there are for the table. For example, if one client acquires a lock for a table usingLOCK TABLE t1 WRITE,In_use is 1. If another client issuesLOCK TABLE t1 WRITE while the table remains locked, the client blocks waiting for the lock, but the lock request causesIn_use to be 2. If the count is zero, the table is open but not currently being used.In_use is also increased by theHANDLER ... OPEN statement and decreased byHANDLER ... CLOSE.

  • Name_locked

    Whether the table name is locked. Name locking is used for operations such as dropping or renaming tables.

If you have no privileges for a table, it does not show up in the output fromSHOW OPEN TABLES.