Re: extended stats on partitioned tables

Tomas Vondra <tomas.vondra@enterprisedb.com>

From: Tomas Vondra <tomas.vondra@enterprisedb.com>

To: Zhihong Yu <zyu@yugabyte.com>

Cc: Justin Pryzby <pryzby@telsasoft.com>, Jaime Casanova <jcasanov@systemguards.com.ec>, PostgreSQL-development <pgsql-hackers@postgresql.org>

Date: 2021-12-12T17:52:00Z

Lists: pgsql-hackers

On 12/12/21 16:37, Zhihong Yu wrote:
> 
> Hi,
> For patch 1, minor comment:
> 
> +           if (planner_rt_fetch(onerel->relid, root)->inh)
> 
> Since the rte (RangeTblEntry*) doesn't seem to be used beyond checking 
> inh, I think it would be better if the above style of checking is used 
> throughout the patch (without introducing rte variable).
> 

It's mostly a matter of personal taste, but I always found this style of 
condition (i.e. dereferencing a pointer returned by a function) much 
less readable. It's hard to parse what exactly is happening, what struct 
type are we dealing with, etc. YMMV but the separate variable makes it 
much clearer for me. And I'd expect the compilers to produce pretty much 
the same code too for those cases.

regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

Add stxdinherit flag to pg_statistic_ext_data
- 269b532aef55 15.0 landed
Build inherited extended stats on partitioned tables
- d6817032d26b 13.6 landed
- 20b9fa308ebf 15.0 landed
- ea212bd95fd2 14.2 landed
- 9d1bcf5dc11a 12.10 landed
- 491182e52909 11.15 landed
- 9211c2e38f09 10.20 landed
Ignore extended statistics for inheritance trees
- 76569ad6f423 12.10 landed
- ff0e7c7e8401 10.20 landed
- b3cac25f4d50 11.15 landed
- acfde7c5837d 13.6 landed
- 2cc007fd0359 14.2 landed
- 36c4bc6e725f 15.0 landed
Don't build extended statistics on inheritance trees
- 859b3003de87 10.10 cited
Tighten up relation kind checks for extended statistics
- 8c5cdb7f4f6e 10.0 cited
Avoid assuming that statistics for a parent relation reflect the properties of
- 427c6b5b9849 8.2.0 cited