On Tue, Oct 30, 2018 at 3:20 PM Andres Freund wrote:
>
> Hi,
>
> On 2018-10-30 16:54:45 -0400, Tom Lane wrote:
> > Andres Freund writes:
> > > On 2018-10-30 16:23:37 -0400, Tom Lane wrote:
> > >> Well, a Lambda expression is not something that can be optimized away
> > >> (unless perhaps you can
Dear Tom, Andres, Andrew, all
Any update on this interesting topic?
--Stefan
P.S. TIL Databricks SQL lambda functions: "A parameterized expression
that can be passed to a function to control its behavior. For example,
array_sort function (Databricks SQL) accepts a lambda function as an
argument
Hi,
On 2018-10-30 16:54:45 -0400, Tom Lane wrote:
> Andres Freund writes:
> > On 2018-10-30 16:23:37 -0400, Tom Lane wrote:
> >> Well, a Lambda expression is not something that can be optimized away
> >> (unless perhaps you can get rid of the need for any of its output Params)
> >> so I don't see
Andres Freund writes:
> On 2018-10-30 16:23:37 -0400, Tom Lane wrote:
>> Well, a Lambda expression is not something that can be optimized away
>> (unless perhaps you can get rid of the need for any of its output Params)
>> so I don't see how any of its subexpressions would ever wind up split out
>
On 2018-10-30 16:23:37 -0400, Tom Lane wrote:
> Andres Freund writes:
> > How did you deal with the fact that we might extract subset of the LET()
> > into e.g. a RestrictionInfo (and then e.g. an IndexPath), but another
> > part would be e.g. evaluated as part of a qual?
>
> Well, a Lambda expre
Andres Freund writes:
> On 2018-10-30 15:04:55 -0400, Tom Lane wrote:
>> The core idea that I'm working on is to invent a new node type
>> LambdaExpr that evaluates an expression and substitutes it as a
>> Param into another expression, notationally sort of like
>> LET($n := expression1 IN ... res
Hi,
On 2018-10-30 15:04:55 -0400, Tom Lane wrote:
> Andres Freund writes:
> > On 2018-10-30 09:30:54 -0400, Tom Lane wrote:
> >> This is all some more fuel for the idea that we need a less messy
> >> substitute for CaseTestExpr. As it happens, I was just fooling with
> >> that yesterday, and hop
[ splitting this off to a new thread ]
Andres Freund writes:
> On 2018-10-30 09:30:54 -0400, Tom Lane wrote:
>> This is all some more fuel for the idea that we need a less messy
>> substitute for CaseTestExpr. As it happens, I was just fooling with
>> that yesterday, and hope to have something t
