Assad Jarrahian <jarraa(at)gmail(dot)com> writes:
> A column of type text contains username's and groupname's followed
> by comma (eg. 'jarraa, mooreg3, keith') [it is stored this way
> because it will be displayed in this format].
You should *not* allow display concerns to drive your database layout.
The pain you are now experiencing is just the first taste of why that's
a bad idea.
Store the usernames and groupnames separately. If you have an
application that's too dumb to concatenate them for itself, you
can make a view on the table that provides the display representation
the application needs.
regards, tom lane