Islam Hegazy wrote:
> Thanks for this information. It was really helpful.
>
> Another problem that is facing me is altering existing functions. For
> example, what if I want to change the execution of the SUM function to
> work as follows:
>
> select sum(a)
> from mytable w(5);
>
> which means to sum only 5 records or records that arrived in the last
> 5 minutes. Do I need to change the core code of PostgreSQL to
> implement such thing?
>
>
The first can be done with a limit clause, the second using a where
clause on a timestamp column - there is no good case that I can see for
either usage, not to mention the question of standards compatibility.
cheers
andrew