Re: Should we add GUCs to allow partition pruning to be disabled? - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Should we add GUCs to allow partition pruning to be disabled?
Date
Msg-id CA+TgmoaAcikptp-hHuHd1uQbNTcEoM-wFtijGEh6uDQ-qqN4ZA@mail.gmail.com
Whole thread Raw
In response to Re: Should we add GUCs to allow partition pruning to be disabled?  (Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>)
Responses Re: Should we add GUCs to allow partition pruning to be disabled?
List pgsql-hackers
On Mon, Mar 11, 2019 at 12:30 AM Amit Langote
<Langote_Amit_f8@lab.ntt.co.jp> wrote:
> Now the question is where to put this text?  Currently, we have:
>
> 5.10. Table Partitioning
>   5.10.1. Overview
>   5.10.2. Declarative Partitioning
>   5.10.3. Implementation Using Inheritance
>   5.10.4. Partition Pruning
>   5.10.5. Partitioning and Constraint Exclusion
>
> Should we add 5.10.6 Notes for the above "note", or should it be stuffed
> under one of the existing sub-headings?

I think it should be added to one of the existing sub-headings.  I
suggest adding it to the end of 5.10.1 and rephrasing it so that it
makes clearer the distinction between what will happen with
inheritance and what will happen with table partitioning, e.g.

When using either declarative partitioning or table inheritance,
partitioning hierarchies with more than a few hundred partitions are
not currently recommended. Larger partition hierarchies may incur long
planning time, and especially in the case of UPDATE and DELETE,
excessive memory usage.  When inheritance is used, see also the
limitations described in Section 5.10.5, Partitioning and Constraint
Exclusion.

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


pgsql-hackers by date:

Previous
From: Evgeniy Efimkin
Date:
Subject: Re: Special role for subscriptions
Next
From: Alvaro Herrera
Date:
Subject: Re: Update does not move row across foreign partitions in v11