Erik Sjoblom <sjoblo...@gmail.com> writes: > I’m observing a storage behavior with arrays in a table that differs from > my expectations, and I’d appreciate your insights. I was to store key value > pairs in a very dense data model. I don't haver the requirement of search > so that's why I was thinking an array of a composite type would work well. > I can see that padding might be involved using the int4 and int8 > combination but there is more overhead. Anyone know where the following it > coming from?
Composite values use the same 24-byte tuple headers as table rows do. So you'd be looking at 40 bytes per array element in this example. A large array of them would probably compress pretty well, but it's never going to be cheap. Can you store the int4's and int8's in two parallel arrays? regards, tom lane