MySQL: Flush Privileges of Single User On Mysql 5.1.72 I created a replication user. Right before running FLUSH PRIVILEGES; this thought passed my mind what if there are any unapplied privilege updates?


How can I flush privileges of a single user? 
How can I check the
list of changes about to get applied once FLUSH PRIVILEGES; is
processed? 
If things go wrong is there any way to revert the
changes?
This answer applies to all versions of MySQL up to, but maybe not including 8.0.


FLUSH PRIVILEGES syncs the entire set of privileges.  No way to flush just one user's.
No way.
Run the equivalent opposite action -- REVOKE &lt;-> GRANT, etc.


A full dump of certain tables in mysql:  user, db and a few others.  This is the 'source of truth' for the current state of all the GRANTs.  Editing the tables with UPDATE (etc) SQL statements has the equivalent effect to GRANT/REVOKE/FLUSH.