John A Meinel <[EMAIL PROTECTED]> writes: > Joel Fradkin wrote: >> Postgres was on the second run >> Total query runtime: 17109 ms. >> Data retrieval runtime: 72188 ms. >> 331640 rows retrieved.
> How were you measuring "data retrieval time"? I suspect he's using pgadmin. We've seen reports before suggesting that pgadmin can be amazingly slow, eg here http://archives.postgresql.org/pgsql-performance/2004-10/msg00427.php where the *actual* data retrieval time as shown by EXPLAIN ANALYZE was under three seconds, but pgadmin claimed the query runtime was 22 sec and data retrieval runtime was 72 sec. I wouldn't be too surprised if that time was being spent formatting the data into a table for display inside pgadmin. It is a GUI after all, not a tool for pushing vast volumes of data around. It'd be interesting to check the runtimes for the same query with LIMIT 3000, ie, see if a tenth as much data takes a tenth as much processing time or not. The backend code should be pretty darn linear in this regard, but maybe pgadmin isn't. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
