On 08/05/18 18:11, Ildar Musin wrote:
On 08.05.2018 17:15, Peter Eisentraut wrote:
On 5/8/18 09:19, Chapman Flack wrote:
On 05/08/2018 08:57 AM, Ildar Musin wrote:
select map (pow(2, x) - 1 for x in array[1,2,3,4,5]);
I wonder how efficient an implementation would be possible
strictly as a
Andrew Gierth wrote:
> > "Andreas" == Andreas Karlsson writes:
>
> Andreas> It would be a pain if the SQL committee started using MAP for
> Andreas> something.
>
> They already did - MAP is a non-reserved keyword in sql2016, used at
> least with . Can't see any obvious
> conflict with use
On 08.05.2018 17:15, Peter Eisentraut wrote:
On 5/8/18 09:19, Chapman Flack wrote:
On 05/08/2018 08:57 AM, Ildar Musin wrote:
select map (pow(2, x) - 1 for x in array[1,2,3,4,5]);
I wonder how efficient an implementation would be possible
strictly as a function, without grammar changes?
Peter Eisentraut writes:
> On 5/8/18 10:18, Alvaro Herrera wrote:
>> How would you invoke it? It seems you'd be forced to use EXECUTE in a
>> plpgsql function, or a C function.
> Yes, I was thinking about a C function.
The thing actually implementing MAP would presumably be in C,
so this doesn'
On 5/8/18 10:18, Alvaro Herrera wrote:
> Peter Eisentraut wrote:
>> On 5/8/18 09:19, Chapman Flack wrote:
>>> On 05/08/2018 08:57 AM, Ildar Musin wrote:
select map (pow(2, x) - 1 for x in array[1,2,3,4,5]);
>>>
>>> I wonder how efficient an implementation would be possible strictly
>>> as
> "Andreas" == Andreas Karlsson writes:
Andreas> It would be a pain if the SQL committee started using MAP for
Andreas> something.
They already did - MAP is a non-reserved keyword in sql2016, used at
least with . Can't see any obvious
conflict with use in expressions, but I haven't checked
On 05/08/2018 02:49 PM, Ildar Musin wrote:
The main point of this patch was about convenience; the performance
thing came out later just as a side effect :) Many users are familiar
with "map/reduce/filter" concept that many languages (not only
functional ones) utilized. And my though was that it
Peter Eisentraut wrote:
> On 5/8/18 09:19, Chapman Flack wrote:
> > On 05/08/2018 08:57 AM, Ildar Musin wrote:
> >>
> >> select map (pow(2, x) - 1 for x in array[1,2,3,4,5]);
> >
> > I wonder how efficient an implementation would be possible strictly
> > as a function, without grammar changes?
>
On 5/8/18 09:19, Chapman Flack wrote:
> On 05/08/2018 08:57 AM, Ildar Musin wrote:
>>
>> select map (pow(2, x) - 1 for x in array[1,2,3,4,5]);
>
> I wonder how efficient an implementation would be possible strictly
> as a function, without grammar changes?
Yeah, you can pass a function to another
On 05/08/2018 09:19 AM, Chapman Flack wrote:
>
> While PostgreSQL certainly has extensions to and divergences from
> standard SQL syntax, some historical and some recent, it seems like
> there ought to be a highish bar for adding new ones; or, looking at it
> another way, has this feature been pro
On 05/08/2018 08:57 AM, Ildar Musin wrote:
>
> select map (pow(2, x) - 1 for x in array[1,2,3,4,5]);
I wonder how efficient an implementation would be possible strictly
as a function, without grammar changes?
While PostgreSQL certainly has extensions to and divergences from
standard SQL syntax,
On 08.05.2018 15:49, Ildar Musin wrote:
select map (pow(x, 2) - 1 for x in array[1,2,3]);
Sorry, the example should be:
select map (pow(2, x) - 1 for x in array[1,2,3,4,5]);
?column?
---
{1,3,7,15,31}
(1 row)
--
Ildar Musin
i.mu...@postgrespro.ru
Hello Tom, Ashutosh,
On 07.05.2018 18:16, Tom Lane wrote:
Ashutosh Bapat writes:
Is there a way we can improve unnest() and array_agg() to match
the performance you have specified by let's say optimizing the
cases specially when those two are used together. Identifying that
may be some work, b
Ashutosh Bapat writes:
> Is there a way we can improve unnest() and array_agg() to match the
> performance you have specified by let's say optimizing the cases
> specially when those two are used together. Identifying that may be
> some work, but will not require introducing new syntax.
+1. The
On Fri, May 4, 2018 at 6:38 PM, Ildar Musin wrote:
> Hello hackers,
>
> Recently I was working with sql arrays in postgres and it turned out
> that postgres doesn't have such very convinient functional constructions
> as map, reduce and filter. Currently to map function over array user has
> to ma
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