Why the {1,255} ? Pg's text type is not varchar, it can get a lot longer than that and still index just fine, and while I can see a restriction on the pre_release stuff -maybe- being useful, compilation/build metadata doesn't seem like something where an enforced maximum length that low is necessarily preferable. (I could see URLs, file paths, repo+path+sha etc. type stuff being useful in metadata and not something the code recording it can really control the length of - it may not do any harm in practice at least for a while, but I don't immediately see what -good- the restriction does, albeit I'm perfectly willing to be told "here's the good thing about it that you didn't think of" ;)