Applies to: 
Azure SQL Database
SQL database in Microsoft Fabric
Empties the database authentication cache containing information about logins and firewall rules, for the current user database. Additionally, it clears all cached Microsoft Entra group membership data stored in the database.
DBCC FLUSHAUTHCACHE doesn't apply to the logical master database, because the master database contains the physical storage for the information about logins and firewall rules.
The user executing the statement and other currently connected users remain connected.
Transact-SQL syntax conventions
Syntax
DBCC FLUSHAUTHCACHE
[;]
Arguments
None.
Remarks
The authentication cache makes a copy of logins and server firewall rules stored in the master database, and places them in memory in the user database.
A user with the KILL DATABASE CONNECTION permission can explicitly terminate a connection to SQL Database by using the KILL (Transact-SQL) command.
DBCC FLUSHAUTHCACHE is not supported for Azure Synapse Analytics.
Permissions
Requires the KILL DATABASE CONNECTION permission SQL Database or the admin account.
Example
The following statement clears the authentication cache for the current database.
DBCC FLUSHAUTHCACHE;