Casey Duncan <[EMAIL PROTECTED]> writes: > Yes, but it may be much more efficient for the human to tell the > computer than for the computer to introspect things. Take, for > example, ndisinct as data grows large.
Yeah, an override estimate for a column's ndistinct seems a perfect example of the sort of statistical hint that I'd be in favor of having. We have also talked about solving the multi-column statistics problem (which, at its core, is "which combinations of columns are worth accumulating stats for?" --- you can't possibly store stats for every combination!) by having what would amount to hints from the DBA saying "keep stats for these combinations". regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org