Hannu Krosing wrote:
> The worst that can happen, is a hash collision, in which case you lose
> the benefits of sync scans, but you wont degrade compared to non-sync
> scans
But it could cause "mysterious" performance regressions, no?
Image that your app includes two large tables, which are both
scannen frequently. Suppose that synchronous scanning gives this
use-case a noticeable performance boost. Now, you dump and reload
your schema, and suddently the hashes of oids of those tables
collide. You percieve a noticeable drop in performance that you
can neither explain nor fix without a rather deep understanding
of postgres internals.
greetings, Florian Pflug