Re: PostgreSQL OR performance - Mailing list pgsql-performance

But it's this materialize that's taking the biggest piece of the time.

> "  ->  Materialize  (cost=469981.13..498937.42 rows=2316503 width=30)
> (actual time=15915.639..391938.338 rows=242752539 loops=1)"

15.9 seconds to 391.9 seconds. That's half your time right there. The
fact that it's ending up with 242 million rows isn't promising - are you
sure the query is doing what you think it is?

> "        ->  Sort  (cost=469981.13..475772.39 rows=2316503 width=30) (actual
> time=15915.599..19920.912 rows=2316503 loops=1)"
> "              Sort Key: production.company.run_id"
> "              Sort Method:  external merge  Disk: 104896kB"

By constrast, this on-disk sort of 104MB is comparatively fast.