SHOW OPEN TABLES Syntax
SHOW OPEN TABLES lists the non-TEMPORARY tables that are currently open in the table cache. See , "How MariaDB Opens and Closes Tables". The FROM clause, if present, restricts the tables shown to those present in the db_name database. The LIKE clause, if present, indicates which table names to match. The WHERE clause can be given to select rows using more general conditions, as discussed in , "Extensions to SHOW Statements".
SHOW OPEN TABLES returns the following columns:
DatabaseThe database containing the table.
TableThe table name.
In_useThe number of table locks or lock requests there are for the table. For example, if one client acquires a lock for a table using
LOCK TABLE t1 WRITE,In_usewill be 1. If another client issuesLOCK TABLE t1 WRITEwhile the table remains locked, the client will block waiting for the lock, but the lock request causesIn_useto be 2. If the count is zero, the table is open but not currently being used.In_useis also increased by theHANDLER ... OPENstatement and decreased byHANDLER ... CLOSE.Name_lockedWhether 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 from SHOW OPEN TABLES.