When organizing available free storage for re-use, we will probably have a choice whether to favor using space in (mostly-) empty blocks, or in mostly-full blocks. Empty and mostly-empty blocks are quicker -- you can put lots of rows in them before they fill up and you have to choose another. Preferring mostly-full blocks improves active-storage and cache density because a table tends to occupy fewer total blocks. Does anybody know of papers that analyze the tradeoffs involved? Nathan Myers [EMAIL PROTECTED] ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html