buildbot/buildbot — pull request #542 by djmitche (2012-10-02 01:46:25+00:00)
Title: Use hashes to ensure master names are unique

(only the final commit is relevant to this pull req)

Other unique columns in the DB cause us grief because MySQL limits the length of unique keys, so we end up with limited-length columns.

A suggested alternative is to push hashes in the unique column, with the full-length text in a non-unique column. That's the technique I've applied here.