Bruce Momjian wrote:
Right, if the cardinality changes, you realize this before execution and optimize/save the plan again. A further optimization would be to save _multiple_ plans for a single prepared plan based on constants and choose one of the other, but that is beyond where we are willing to consider at this stage, I think.
ok .. so you store the cardinality that was used when generating the original plan. on the next execution you look up the cardinality again and compare it, if its off too much, you replan. however this could in extreme cases mean that you replan on every execution and thereby killing off the entire advantage of storing the plan. but thats the absolute worse case scenario. regards, Lukas PS: bruce original email was only send to me directly .. ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq