Re: Tagging rows into collections?

Tom Lane wrote:
>
> Steve Wampler <swampler(at)noao(dot)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.

Still 7.1. I'd rather not rely on the timestamp resolution, though
that would probably work with 7.2's resolution.

> 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.

I'll try the two-table approach - thanks!

How can I associate <timestamp,event_name> entries in the first
table with <name,value> entries in the second? Would using the OID
work - and, if so, how? (Since insertion performance is important,
I'd like to avoid having to do an: [insert <timestamp,event_name>;
query-to-get-id;insert <name,value> sequences]. Is there a way in
SQL to set up the linkage between a row in the first table and
(multiple) rows in the second table?

Thanks!
--
Steve Wampler -- swampler(at)noao(dot)edu
The gods that smiled on your birth are now laughing out loud.