To: Steve Wampler <swampler@noao.edu>
Cc: postgres-sql <pgsql-sql@postgresql.org>
Subject: Re: Tagging rows into collections? 
In-reply-to: <3D10AAFB.D51B1B66@noao.edu> 
References: <3D10AAFB.D51B1B66@noao.edu>
Comments: In-reply-to Steve Wampler <swampler@noao.edu>
	message dated "Wed, 19 Jun 2002 09:02:03 -0700"
Date: Wed, 19 Jun 2002 17:19:31 -0400
Message-ID: <7413.1024521571@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Steve Wampler <swampler@noao.edu> writes:
>  An event has:  timestamp,event_name,list_of_attributes
>    The list_of_attributes are simple (string) name,value pairs.

> However, although selection performance isn't a priority, the
> ability to reconstruct the events from the database is needed
> and the above simple table doesn't provide enough information
> to do so.  (The resolution on the timestamp field isn't
> enough to distinquish separate events that have the same name.)

What PG version are you using?  In 7.2 the default timestamp resolution
is microseconds, rather than seconds.  That might be enough to fix your
problem.

If not, your two-table approach sounds reasonable.  You could stick
with one table and use arrays for the name/value columns, but that
will make searches harder.

			regards, tom lane