On Fri, Oct 14, 2011 at 9:32 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > We could hack around this by adding more columns to the result so that > an index-only scan doesn't work. But I wonder whether it wouldn't be > smarter to add ORDER BY clauses to the window function calls. I've been > known to argue against adding just-in-case ORDER BYs to the regression > tests in the past; but these cases bother me more because a plan change > will not just rearrange the result rows but change their contents, > making it really difficult to verify that nothing's seriously wrong.
I'm not sure if it applies to this case but I recall I was recently running queries on Oracle that included window functions and it wouldn't even let me run them without ORDER BY clauses in the window definition. I don't know if it cleverly determines that the ORDER BY will change the results or if Oracle just requires ORDER BY on all window definitions or what. -- greg -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
