Hello Three years ago we worked on implementation of median function.
http://www.postgresql.org/message-id/aanlktimrksuoggsk7-gtxnvjjgl-1qvuqxiduszqw...@mail.gmail.com Can we implement this function now? There are a few opened questions: * immutable parameters of aggregate functions * effective implementation when data are in memory * effective implementation when data are out of memory * effective implementation for usage as window function - running median. Better than before, we can choose between hashing and sorting based aggregation. But tuplesort implementation is not right for using as window function. Second issue can be a not possible reusing of tuplesort for more final functions - median, percentile in one query. Ideas how to solve this task? Can we move forward in some points? Regards Pavel
