Juliet,
> My first question is about oid's. What are they exactly and when
> should/shouldn't I use them. I had trouble finding any information on
> them in either the online documentation or the online books. I'm
> using pgadmin to develop my database and I noticed that once I select
> or don't select oid that I can't change my mind.
We need a FAQ on this. Sigh.
OIDs are for system use. Occasionally some developers will build
transaction tables, to which thousands or millions of records will be
written and erased per day. For that case (and that case only) they
will build "OID-less tables" in Postgres 7.2.
Otherwise, you should build your tables with OIDs, but then ignore the
OIDs and not use them as an index. The system helps by "hiding" the
OID column from you.
Should you run across documentation suggesting that you use the OID as
an index or primary, key, that documentation is outdated.
-Josh Berkus