Josh Berkus <[EMAIL PROTECTED]> writes: > I now have a simple test case which shows significant performance > degradation on 8.3devel for a specific query, apparenly due to an > unnecessary call to Top-N sort.
It does the right thing if t_s_symb is declared as text instead of varchar. When it's varchar, even setting enable_sort off won't make it pick the right plan, which suggests that it fails to recognize that the index can match the query's ORDER BY. I'm guessing I overlooked a binary-compatibility case when I rejiggered the handling of PathKeys in connection with the NULLS FIRST/LAST stuff. No time to look deeper right now. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly