Re: Using "LIMIT" is much faster even though, searching

Hyun-Sang,

> before test, I already executed VACUUM FULL.
> this result show up after vacuum full.

Really?   Your results really look like a bloated table.   Can you run VACUUM 
FULL ANALYZE VERBOSE on the table and post the output?

> When I using index scan, the result was almost same, that means, there
> was no time difference, so i'll not mention about index scan.

Can we see an index scan plan anyway?   EXPLAIN ANALYZE?

Oh, and if this is a zip codes table, why are you using a sequence as the 
primary key instead of just using the zip code? 

-- 
Josh Berkus
Aglio Database Solutions
San Francisco