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. See Section 7.4.8, “How MySQL 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
Section 19.30, “Extensions to SHOW
Statements”.
SHOW OPEN TABLES
returns the
following 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 using LOCK TABLE t1 WRITE
,
In_use
will be 1. If another client
issues LOCK TABLE t1 WRITE
while the
table remains locked, the client will block waiting for the
lock, but the lock request causes In_use
to be 2. If the count is zero, the table is open but not
currently being used. In_use
is also
increased by the
HANDLER ...
OPEN
statement and decreased by
HANDLER ...
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 from SHOW OPEN TABLES
.
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