From: Rik Wasmus
Date: July 13 2012 7:51am
Subject: Re: why this query doesn't use index?
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> can you tell me why my this query doesn't use the index?
> 
> 
> mysql> explain select * from iploc where 1902800418 between start_ip
> and end_ip;

Hazarding a very quick guess: if this table is what I think it is (NON-
overlapping IP ranges + (geo)location), you might want to try:

SELECT *  FROM iploc 
WHERE start_ip < 1902800418
ORDER BY start_ip DESC
LIMIT 1

... at least, that is how we solved our geoip-performance problems. The NON-
overlappig part is crucial though.
-- 
Rik Wasmus