[graemep]

Benchmarks are not the reason people choose PostgreSQL over MySQL. I have never even bothered to benchmark the two for any project that could have used either.

Features, better ACID (at least historically) and maybe better standards compliance.

The big one for me is being able to run schema changes in transactions, which makes it easy to roll back a failed migration.

[mdavidn]

Also, the license. PostgreSQL is controlled by the open source community via a nonprofit organization.

[graemep]

True, but I would say governance rather than license.

Not being Oracle is a huge advantage ;)