Subject Which connection causes object in use - is there a way to find that out?
Author Tomasz Tyrakowski

From time to time, when I try to alter a stored procedure in a
production database, I get "object in use" error. I was wandering, is
there a way to find the connections (users) that prevent a particular
procedure from being altered?
Querying MON$STATEMENTS is a no-go, no statement currently being
executed uses the procedure (directly) and yet an alter results in
"object in use".

thanks in advance