Re: CLUSTER not lose indexes

Bruce Momjian dijo:

> Alvaro Herrera wrote:
> > Hackers:
> >
> > I've modified commands/cluster.c so that it recreates the indexes on the
> > table after clustering the table. I attach the patch.

> I think Tom was suggesting that you may want to continue work on CLUSTER
> and make use of relfilenode. After the cluster, you can just update
> pg_class.relfilenode with the new file name (random oid generated at
> build time) and as soon as you commit, all backends will start using the
> new file and you can delete the old one.

I'm looking at pg_class, and relfilenode is equal to oid in all cases
AFAICS. If I create a new, "random" relfilenode, the equality will not
hold. Is that OK? Also, is the new relfilenode somehow guaranteed to
not be assigned to another relation (pg_class tuple, I think)?

> In this code, we delete the old relation, then rename the new one. It
> would be good to have this all happen in one update of
> pg_class.relfilenode; that way it is an atomic operation.

OK, I'll see if I can do that.

> Let us know if you want to pursue that and we can give you additional
> assistance. I would like to see CLUSTER really polished up. More
> people are using it now and it really needs someone to focus on it.

I thought CLUSTER was meant to be replaced by automatically clustering
indexes. Isn't that so? Is anyone working on that?

> Glad to see you working on CLUSTER. Welcome aboard.

Thank you. I'm really happy to be able to work in Postgres.

--
Alvaro Herrera (<alvherre[a]atentus.com>)
"Limitate a mirar... y algun dia veras"