RENAME DATABASE statement changes the name of a database.
Database renames are not transactional. For more information, see Database renaming considerations.
Only members of the
admin role can rename databases. By default, the
root user belongs to the
||The first instance of
Database renaming considerations
Database renames are not transactional. There are two phases during a rename:
system.namespacetable is updated. This phase is transactional, and will be rolled back if the transaction aborts.
- The database descriptor (an internal data structure) is updated, and announced to every other node. This phase is not transactional. The rename will be announced to other nodes only if the transaction commits, but there is no guarantee on how much time this operation will take.
- Once the new name has propagated to every node in the cluster, another internal transaction is run that declares the old name ready for reuse in another context.
This yields a surprising and undesirable behavior: when run inside a
COMMIT block, it’s possible for a rename to be half-done - not persisted in storage, but visible to other nodes or other transactions. This violates A, C, and I in ACID. Only D is guaranteed: If the transaction commits successfully, the new name will persist after that.
Rename a Database
> SHOW DATABASES;
+---------------+ | database_name | +---------------+ | db1 | | db2 | | defaultdb | | postgres | | system | +---------------+ (5 rows)
> ALTER DATABASE db1 RENAME TO db3;
> SHOW DATABASES;
+---------------+ | database_name | +---------------+ | db2 | | db3 | | defaultdb | | postgres | | system | +---------------+ (5 rows)
Rename fails (new name already in use)
> ALTER DATABASE db2 RENAME TO db3;
pq: the new database name "db3" already exists