# Database Level Locks

* A database level lock is taken on the database that the operation is operating on. While an operation holds a database level lock, no other operation that requires the same lock can operate on that database.
* A database level lock can be taken concurrently with locks on other databases in the same cluster. For example, two ALTERs can run simultaneously on two different databases.
* If a database level lock is taken, it will block a cluster lock from being taken.
* DML operations are not affected by these locks.
* DDL operations that are affected by these locks are listed in [Operations that Take Database Level Locks](https://docs.singlestore.com/db/v9.1/reference/sql-reference/operations-that-take-either-a-database-or-a-cluster-level-lock/operations-that-take-database-level-locks.md).
* Any blocked operations will queue.

Example: Database `a` takes a shared lock to perform `CREATE DATABASE`. Database `b` takes a shared lock to perform `BACKUP DATABASE` concurrently.

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Modified at: August 30, 2022

Source: [/db/v9.1/reference/sql-reference/operations-that-take-either-a-database-or-a-cluster-level-lock/database-level-locks/](https://docs.singlestore.com/db/v9.1/reference/sql-reference/operations-that-take-either-a-database-or-a-cluster-level-lock/database-level-locks/)

(An index of the documentation is available at /llms.txt)