What's the deal with the various MySQL versions?

I haven't been paying attention for a while, but I just checked and the latest release of MySQL is at 5.5.

I always use what the vendor of whatever OS I'm using provides, which has been 5.0 or 5.1 for the last couple years.

This page lists two community versions, 5.1 and 5.5: http://dev.mysql.com/

There is documentation for 5.0, 5.1, 5.4, 5.5: http://dev.mysql.com/doc/refman/5.0/en/insert-select.html

So:

开发者_如何学运维
1. What happened to 5.2, and 5.3?
2. Why do all distros, even the newest Ubuntu which is not considered to be particularly conservative, only ship with 5.0 and 5.1?

dev.mysql.com is the DEVELOPMENT stream - both the community and enterprise listings are 5.1.

That's why there's no 5.2 or 5.3 - 5.5 hasn't been released (to public, anyways). But version numbers are semantic - marketing will muck with them for sake of better presentation.

5.1 is the latest GA version, others (5.4, 5.5, whatever other number they're using) are not considered ready for production use. Therefore the distros won't ship it, in particular because they might include features which subsequently get dropped, and your app might then depend on them (MySQL don't guarantee continued support of features not yet present in any GA version).

I would suggest always using Sun/Oracle binaries rather than Linux distribution ones, as they will not include dodgy vendor patches, which history suggests do not always improve software.