Re: New feature: accumulative functions. - Mailing list pgsql-general

From Radosław Smogura
Subject Re: New feature: accumulative functions.
Date
Msg-id 201109252009.05512.rsmogura@softperience.eu
Whole thread Raw
In response to New feature: accumulative functions.  (pasman pasmański <pasman.p@gmail.com>)
List pgsql-general
pasman pasmański <pasman.p@gmail.com> Sunday 25 of September 2011 15:19:28
> Hi.
>
> I propose to add "accumulative" flag to a function definition. This
> flag would be set for function f(x) which is accumulative and
> immutable.
>
> This flag allows to use an index on  x for clauses containing f(x):
>
> where f(x) = const
I think for this index designe will require that f(x) will be stored,
additional behaviour of fucntion are not required, is quite enaugh that it
will be function.

> where f(x) > const
>
> and so on.
By this assume that "accumulative" function is
(weakly) increasing or decreasing

f such that x < y => f(x) <= f(y)
?

I only may deduce it for idea that search will be faster on index.

Regards,
Radosław Smogura
http://softperience.eu/

pgsql-general by date:

Previous
From: Tom Lane
Date:
Subject: Re: pg_dump compress
Next
From: pasman pasmański
Date:
Subject: Re: New feature: accumulative functions.