On Fri, 23 Jan 2003, Hannu Krosing wrote: > > 1. [OIDs are] not a relational concept. > so are other system tuples (cid, tid, tableiod, ...).
But there's a key difference here; nobody's advertising these others as any sort of row identifier: i.e., a candidate key. And besides, I wouldn't object at all to getting rid of these, except that they store essential system information and I can't figure out how to get rid of them. :-) > It is an OO concept. Well, it's not, because we have an OID wrap-around problem, so an OID is actually not an OID at all, but simply an arbitrary number tacked on to a row. Other rows, in the same or other tables can have the same OID. > > 2. The OID wraparound problem can get you. > put an unique index on OID column. That still doesn't make it a real OID, because you can't guarantee that two rows in different tables won't have the same OID. > > 3. Other SQL databases don't do this. > Ask Date, hell tell you that SQL is evil, i.e. not relational ;) I did, he said that, and I agreed with him. :-) So now we have something that's evil because it's not relational and also evil because it's not SQL. Double-yuck! > > 5. We should default to what gives us better performance, rather than > > worse. > Not if it breaks anything ;) I disagree. We have to weigh the cost of the breakage versus the benefits in each individual circumstance. We've broken plenty of things before because we felt it was better to do so than maintain backward compatability. Because of its history as a research tool, there's a lot of experimental stuff in postgres that, in hindsight, we can say didn't work so well. When we find something that's not working so well, we should at least consider making some sort of move toward the "right thing," rather than continuing to do the wrong thing forever just for the sake of backwards compatability. Summary: I don't want to hear absolutes like "we should never break backwards compatibility." I want to hear arguments that the cost of breaking backwards compatability is X, and the benefit of the new way of doing things is Y, and here is why you think X > Y. cjs -- Curt Sampson <[EMAIL PROTECTED]> +81 90 7737 2974 http://www.netbsd.org Don't you know, in this new Dark Age, we're all light. --XTC ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
