Hannu Krosing <[EMAIL PROTECTED]> writes: > Maybe the quicker way to avoid duplicate-element bugs (and get faster > merges) is to keep the lists ordered, so instead of just appending the > next int, you scan to the proper place and put it there (if it is not > there already).
I had thought of doing that before it occurred to me to switch to a bitmap representation, but I was always afraid to --- I think it would be more buggy not less so. The compiler won't give any help in catching places where plain-list operations are applied to what should be an ordered list. If I change the struct type completely, then the compiler will help me. Also, the bitmap representation makes for a nice reduction in palloc() traffic (typically one palloc per set, not one per set element). That part of the performance gain won't be there if we just change to ordered lists. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])