What causes mysql table lock?
Table locking causes problems when a session is waiting because the disk is full and free space needs to become available before the session can proceed. In this case, all sessions that want to access the problem table are also put in a waiting state until more disk space is made available.
How does mysql detect deadlock?
InnoDB automatically detects transaction deadlocks and rolls back a transaction or transactions to break the deadlock. InnoDB tries to pick small transactions to roll back, where the size of a transaction is determined by the number of rows inserted, updated, or deleted.
What is isolation level in MySQL?
Isolation is the I in the acronym ACID; the isolation level is the setting that fine-tunes the balance between performance and reliability, consistency, and reproducibility of results when multiple transactions are making changes and performing queries at the same time.
Is there an automatic password expiration policy in MySQL?
MySQL enables database administrators to expire account passwords manually, and to establish a policy for automatic password expiration. Expiration policy can be established globally, and individual accounts can be set to either defer to the global policy or override the global policy with specific per-account behavior.
What does it mean to lock a table in MySQL?
A lock is a flag associated with a table. MySQL allows a client session to explicitly acquire a table lock for preventing other sessions from accessing the same table during a specific period. A client session can acquire or release table locks only for itself.
How to release the read lock in MySQL?
From the first session, use the SHOW PROCESSLIST statement to show detailed information: After that, go back to the first session and release the lock by using the UNLOCK TABLES statement. After you release the READ lock from the first session, the INSERT operation in the second session executed.
Where do I Find my locked account in MySQL?
Account locking state is recorded in the account_locked column of the mysql.user system table. The output from SHOW CREATE USER indicates whether an account is locked or unlocked. If a client attempts to connect to a locked account, the attempt fails.