# Lock-free Backups

Lock-free backups do not block `INSERT`, `UPDATE`, and `DELETE` operations at any point during a backup. They do not need to lock and wait for write queries. Lock-free backups are enabled by default

However, `ALTER DATABASE` command will not run while there is a backup job active on the relevant database.  The backup takes the cluster operations lock for the entirety of the backup.

## Commands Blocked by the BACKUP Process

* `ALTER DATABASE`
* `DROP DATABASE`

## Commands Not Blocked by the BACKUP Process

* `CREATE TABLE` (columnstore and rowstore)
* `ALTER TABLE` (columnstore and rowstore)
* `DROP TABLE` (columnstore and rowstore)
* `DELETE TABLE`
* `INSERT TABLE`
* `TRUNCATE TABLE` (columnstore and rowstore)
* `CREATE INDEX`
* `DROP INDEX` (columnstore and rowstore)
* `CREATE VIEW`
* `DROP VIEW`
* `ANALYZE TABLE` (columnstore and rowstore)
* `OPTIMIZE COLUMNSTORE TABLE`
* `SHOW TABLE STATUS`
* `SHOW DATABASE STATUS`
* `OPTIMIZE ROWSTORE TABLE`

***

Modified at: July 11, 2025

Source: [/db/v9.1/manage-data/back-up-and-restore-data/lock-free-backups/](https://docs.singlestore.com/db/v9.1/manage-data/back-up-and-restore-data/lock-free-backups/)

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