[platonichvn]

I agree with you but I often question when people list "lock in" as an issue. How often do you see projects where they decide to move from one db to another? Even in cases where an ORM is used, making the migration process painless in theory, I doubt many projects take the risk and exercise their freedom of not being locked in.

[joevandyk]

I've only seen people move to postgresql (generally from mysql). I've never heard of people moving away from postgresql. Granted, that's a small sample size.

[pvh]

Etsy did. I don't think it was a good decision and I think the reasons they did had more to do with resetting from some bad architecture decisions, but they're the example I know of. http://codeascraft.etsy.com/2011/09/28/scaling-etsy-what-wen... I think the big lesson here would be: don't have separate DBA and Engineering teams.

On the other hand, I could name quite a few people who went the other way, like Urban Dictionary who run on our http://postgres.heroku.com service, too. (I don't normally name customers, but he recorded a video saying he liked us so I think it's fair game. http://success.heroku.com/urbandictionary )

[gouranga]

If you look at most "corporate" IT platforms, they tend to have favourite database engines that they need to use. If you have DBMS portability, then it gets one foot in the door straight away.

Also contrary to the norm here, some applications last a long time. The one I work with daily is actually 20 years old this year. In that time a lot has changed and in the next 20 years a lot will as well. It makes sense for long-lived applications to plan well ahead and consider paradigm and architecture changes.

This platform started in C++ on OS/2 with Oracle running on VAX/VMS at the back end. It went to Java/J2EE with an Oracle back end in the early 00's. It's now SQL Server and .Net.

[cageface]

You have to admit that a 20 year old app with over a PB of data and millions of lines of code is not exactly typical. For most apps the benefits of a structured database outweigh the costs.

[neeleshs]

Interesting to know what abstractions were found useful when migrating from VAX/VMS to Java/J2EE to .Net.

[gouranga]

Hibernate and nhibernate.

[gouranga]

I'd like to know the reason that was downvoted...