Here is a new patch for this. This now follows the implementation that
Tom has suggested: Leave date_part() alone, add a new set of extract()
functions, and map the SQL EXTRACT construct to those. I have basically
just copied over the implementations from my previous patch and placed
them next to the existing date_part() implementations. So all the
behavior is still the same as in the previous patches.
One thing I still need to look into is how to not lose all the test
coverage for date_part(). But that should be fairly mechanical, so I'm
leaving it off in this version.
--
Peter Eisentraut
2ndQuadrant, an EDB company
https://www.2ndquadrant.com/
