Honestly the deal killer for me with Postgres has always been replication. I believe they're rolling out a replication package as part of the standard distribu

Honestly the deal killer for me with Postgres has always been replication. I believe they're rolling out a replication package as part of the standard distribution soonish, but previously it was stated as "not a core feature". There were one or two commercial replication packages which I didn't get a chance to play with, but the "standard" replication for Postgres, Slony, is incredibly difficult to deal with. By comparision, MySQL's replication tends to "just work" (easier configuration, easier to diagnose & fix problems, setup, tweak, etc). It also had a lot to do with marketing and buzz; Postgres seems to have been happy to chug along in the background while a lot of big sites like Slashdot were pushing the tool they used. Keep in mind originally MySQL was not GPL and did not ship with RedHat, the default was Postgres. I recall when MySQL changed their licensing and RedHat started shipping them, it signified a pretty rapid change in what people were using. All things considered, everytime I use Postgres I'm fairly impressed. I've been able to pretty painlessly migrate Oracle based systems directly to Postgres with it's PL/SQL compatibility, and it's Python stored procedure stuff is useful.