Re: Joins and full index scans...mysql vs postgres?

PFC <lists@peufeu.com>

From: PFC <lists@peufeu.com>
To: "ryan groth" <postgres@cpusoftware.com>, "Stephan Szabo" <sszabo@megazone.bigpanda.com>, "Steinar H. Gunderson" <sgunderson@bigfoot.com>, pgsql-performance@postgresql.org
Date: 2006-02-22T23:18:58Z
Lists: pgsql-performance
> "997+3522 ms". Am I reading these numbers wrong? Are these numbers
> reflective of application performance? Is there an optimization I am
> missing?

	It also reflects the time it takes to pgadmin to insert the results into  
its GUI...

	If you want to get an approximation of the time the server needs to  
process your request, without the data marshalling time on the network and  
anything, you can either use EXPLAIN ANALYZE (but mysql doesn't have it,  
and the instrumentation adds overhead), or simply something like "SELECT  
sum(1) FROM (query to benchmark)", which only returns 1 row, and the sum()  
overhead is minimal, and it works on most databases. I find it useful  
because in knowing which portion of the time is spent by the server  
processing the query, or in data transfer, or in data decoding on the  
client side, or simply in displaying...