Hello,
Using Hibernate3 & Postgresql8 on Win32. I'm much more of a Java developer than SQL user, so any heuristic guidance is welcome. I notice the default string length in my database is 256 - not 200, 250, 257, 300 etc - but on a "standard binary boundary" of 256. Abviously I'll optimise my string lengths as necessary - but is it preferrable to maintain a "standard binary boundary"??? Lets say I want length 10 - should I just round up to 16? Should 50 go to 64, 100 to 128??? Is there a potential big advantage if I could bring a "130 down to 128"??? Or is all this quite marginal and I should concentrate my efforts elsewhere??

I realise this may be very implementation dependent - but any guidance is appreciated.
Thanks.

It may be worthwhile to ensure the size of a whole row is a multiple of the underlying architecture's cache-line size, 64b on most modern x86 CPUs. Aside from that, I doubt there is going to be any measurable difference in any usage scenario. I still try to keep my string lengths to powers of 2, for 'conceptual elegance' :)