[jsizzle]

I would maintain that if you are experiencing poor performance for a web site, there are MUCH more fruitful places to look than DNS latency. Third party objects, excessive page sizes, lack of overall optimization based on device are just the tip of the iceberg.

[edoceo]

For many apps I've worked the DB connection setup was always the slow part (use PgBouncer). Then, the part was the queries. DNS, gziped CSS/JS - chasing a red-herring.

[jsizzle]

Yeah definitely. A poorly crafted SQL query can wreak havoc on performance, especially at scale!