Re: [HACKERS] Partition-wise join for join between (declaratively)partitioned tables - Mailing list pgsql-hackers

From Robert Haas
Subject Re: [HACKERS] Partition-wise join for join between (declaratively)partitioned tables
Date
Msg-id CA+TgmoZt=JpVvCepS5pxu2M-SOwh_50AXDyUvEDDxqyG58FX1A@mail.gmail.com
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In response to Re: [HACKERS] Partition-wise join for join between (declaratively)partitioned tables  (Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>)
List pgsql-hackers
On Mon, Mar 20, 2017 at 9:44 AM, Ashutosh Bapat
<ashutosh.bapat@enterprisedb.com> wrote:
> Right. If we could use parent Vars to indicate parent Var or child Var
> depending upon the context, a lot of memory issues would be solved; we
> wouldn't need to translate a single expression. But I think that's not
> straight forward. I have been thinking about some kind of polymorphic
> Var node, but it seems a lot more invasive change. Although, if we
> could get something like that, we would save a huge memory. :)

Yes, that's why I'm interested in exploring that approach once the
basic framework is in place here.

> I am wondering whether we need to change
> calc_non_nestloop_required_outer() similar to
> calc_nestloop_required_outer() just to keep their signatures in sync.

I haven't looked at the patch, but I don't think you need to worry about that.

> Should I work on completing reparamterized_path_by_child() to support
> all kinds of paths?

Yes, or at the very least all scans, like reparameterize_path() already does.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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