"Robert Haas" <[EMAIL PROTECTED]> writes: > On Mon, Dec 8, 2008 at 10:24 AM, Gregory Stark <[EMAIL PROTECTED]> wrote: >> I tried a different query, trying to get quadratic growth and again failed. >> It
> The profiling results I sent the other day show an exactly-linear > increase in the number of times eqjoinsel invokes FunctionCall2. > Reading through the the eqjoinsel_inner loop in selfuncs.c beginning > around line 2042, I think what is happening is this: since the two > tables are really the same table, nvalues1 and nvalues2 are the same > array, and therefore contain the same elements in the same order. Yeah, that would be fast. To see a quadratic case you need MCV arrays that have little or no overlap of common values --- then each element of the first will be compared (in vain) to all or most of the elements in the second. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers