2008/8/30 Hitoshi Harada <[EMAIL PROTECTED]>: > Here's the latest window functions patch against HEAD. It seems to be > ready for the September commit fest, as added documents, WINDOW clause > feature and misc tests. I guess this would be the window functions > feature freeze for 8.4. The remaining feature will be implemented for > the later release. > > This patch consists of: > - windowed aggregates > - cooperate with GROUP BY aggregates > - some optimizations with multiple windows > - ranking functions > - WINDOW clause > - windowing SQL regression tests > - sgml documents > > Looking up the total road map, the dropped features are: > > - sliding window (window framing) > - lead(), lag(), etc. that reach for random rows > - user defined window functions > > The first and second topics are difficult to implement currently. > Because these features require random row access, it seems that > tuplestore would be able to save multiple positions to mark/restore. > This is fundamental change that is over my capability. Also, user > defined window functions seem to have much more to decide. I think I > can't put into shape the general needs of user's window functions now. > Lacking these feature, this stage looks compatible to SQLServer 2005, > while Oracle and DB2 have almost full of the specification. > > Also, current implementation has only a type of plan which uses sort > operation. It should be optimized by re-position the windows and/or > using hashtable. > > Oh, git hosting repository is updated as well.
README is updated. http://umitanuki.net/pgsql/wfv04/design.html Please add link to commit fest wiki. Regards, -- Hitoshi Harada -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
