What happens if you lock a table with a lock table?
If you lock a table explicitly with LOCK TABLES, any tables used in triggers are also locked implicitly, as described in Section 13.3.5.2, “LOCK TABLES and Triggers”. UNLOCK TABLES explicitly releases any table locks held by the current session.
Can a server restore a table that is not locked?
So, the restore is asking the server to ALTER a table that isn’t locked. You can only do that when your session has no tables locked at all. If you change that table name to your test table name, the restore should work.
Is there a way to lock mysql table?
Table locks can be acquired for base tables or views. You must have the LOCK TABLES privilege, and the SELECT privilege for each object to be locked. For view locking, LOCK TABLES adds all base tables used in the view to the set of tables to be locked and locks them automatically.
Is it possible to lock a table without an alias?
It does not work to lock the table without specifying the alias. Conversely, if you lock a table using an alias, you must refer to it in your statements using that alias. then I read from , this raises Table ‘table_a’ was not locked with Lock Tables.
When does unlock tables implicitly commit a transaction?
UNLOCK TABLES implicitly commits any active transaction, but only if LOCK TABLES has been used to acquire table locks. For example, in the following set of statements, UNLOCK TABLES releases the global read lock but does not commit the transaction because no table locks are in effect: Press CTRL+C to copy.
How are lock tables and unlock used in MySQL?
For cascading updates, a shared-nothing write lock ( LOCK TABLES WRITE) is taken on related tables that are involved in the operation. UNLOCK TABLES explicitly releases any table locks held by the current session. LOCK TABLES implicitly releases any table locks held by the current session before acquiring new locks.
Which is the best use for unlock tables?
Another use for UNLOCK TABLES is to release the global read lock acquired with the FLUSH TABLES WITH READ LOCK statement, which enables you to lock all tables in all databases. See Section 13.7.6.3, “FLUSH Syntax”. (This is a very convenient way to get backups if you have a file system such as Veritas that can take snapshots in time.)