2014-06-05 17:18 GMT+07:00 Marc Mamin <m.ma...@intershop.de>: > I'm thinking about adding a final function to my aggregate that would replace > zero values will nulls, > hence transforming the intarray into a standard int[], possibly with > nullbitmap and a lowerbound that can be > 1. > This will probably degrade the performance considerably, but may reduce the > size of the end result for spare data and not too small integers... > Performances should greatly depend on the data distribution and order as they > influence the number of palloc. > My first tests shown as well better and poorer results. > > My target is not to get better performances at the first place, but to get a > pivot structure in an early aggregation stage.
Usually for pivot, i use crosstab function from tablefunc (http://www.postgresql.org/docs/9.4/static/tablefunc.html#AEN158550). If your patch doesn't perform better, it's more easier to just use crosstab. For storing it efficiently, the result can be transformed into array manually. PS: as Michael Paquier said above, its better if you could send the patch in the .patch file format (see: https://wiki.postgresql.org/wiki/Working_with_GIT). -- Ali Akbar -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
