Temporary database option dqp_enabled allows you to enable or disable DQP at the connection level.
You can set the temporary database option dqp_enabled to OFF to disable DQP for the current connection. You can set the option to ON (the default value) to enable DQP for the current connection, but only when DQP is enabled for the user by that user's login policy for the logical server of the current connection.
Setting dqp_enabled to ON results in an error if DQP is disabled based upon the user's login policy:
Invalid setting for option 'dqp_enabled'
Any changes you make to a user's login policy options affect new connections only. Login policy option settings for existing connections are based upon the time the connection was initially established.