"Marc G. Fournier" <scrappy@postgresql.org> writes:
> On Thu, 1 Jan 2004, Tom Lane wrote:
>> "Marc G. Fournier" <scrappy@postgresql.org> writes:
>>> what sort of impact does CLUSTER have on the system? For instance, an
>>> index happens nightly, so I'm guessing that I'll have to CLUSTER each
>>> right after?
>>
>> Depends; what does the "index" process do --- are ndict8 and friends
>> rebuilt from scratch?
> nope, but heavily updated ... basically, the indexer looks at url for what
> urls need to be 're-indexed' ... if it does, it removed all words from the
> ndict# tables that belong to that url, and re-adds accordingly ...
Hmm, but in practice only a small fraction of the pages on the site
change in any given day, no? I'd think the typical nightly run changes
only a small fraction of the entries in the tables, if it is smart
enough not to re-index pages that did not change.
My guess is that it'd be enough to re-cluster once a week or so.
But this is pointless speculation until we find out whether clustering
helps enough to make it worth maintaining clustered-ness at all. Did
you get any results yet?
regards, tom lane
