Dan S <strd911@xxxxxxxxx> writes: > I'm trying to write a window function in C . > In the function I'm using a tuplesort to sort the window data and then do > some processing. Hmm ... why do you feel you need to do that? The window function's input should already be sorted according to the window specification. > Now when I'm running the function I get this: 'WARNING: temporary file > leak: File 43 still referenced' > The warning comes from my failure to call tuplesort_end at the appropriate > time. Unsurprising. > So I think I need to use some callback mechanism to get that to work. > I've found some reference in the postgres source code to > RegisterExprContextCallback which seemed promising but I have no idea how > to get the right expression context to put in as the first argument to that > function. I don't think there is one :-(. WindowAgg has a per-input-tuple econtext, and a per-output-tuple econtext, but what you'd need for this is a partition-lifespan econtext, which doesn't exist. It's possible that we could promote the "partcontext" memory context into a full econtext so as to support this sort of behavior. But I'd want to see a reasonably convincing use-case for it. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
