yary <not.com@gmail.com> writes:
> Is there a link between Sybase and Postgres?
Not that I've ever heard of.
> I ask because I came across a bug in Netezza, and Netezza has a
> well-known Postgres lineage, but when web-searching the bug, the first
> thing I found was a Sybase reference-
>
http://geekswithblogs.net/marocanu2001/archive/2011/08/11/nasty-bug-in-sybase-iq-analytical-function-last_value-over-partition.aspx
> and indeed that is the exact bug I found in Netezza! "first_value"
> works great, "last_value" has window size 1 unless you also say "rows
> between unbounded preceding and unbounded following".
That isn't a bug, it's the behavior required by the SQL standard. The
blogger you cite has apparently not bothered to read same (or much of
any documentation), or he would know that the default window frame is
NOT unbounded preceding to unbounded following. Our own docs point out
specifically that you probably want a nondefault frame for last_value
--- see http://www.postgresql.org/docs/9.2/static/functions-window.html
towards the bottom of the page.
regards, tom lane