Re: [HACKERS] WITH clause in CREATE STATISTICS

On 21 April 2017 at 22:30, Tels <nospam-pg-abuse@bloodgate.com> wrote:
> I'd rather see:
>
>  CREATE STATISTICS stats_name ON table(col);
>
> as this both mirrors CREATE INDEX and foreign keys with REFERENCES. It
> could also be extended to both more columns, expressions or other tables
> like so:
>
>  CREATE STATISTICS stats ON t1(col1, col2 / 2), t2 (a,b);
>
> and even:
>
>  CREATE STATISTICS stats ON t1(col1, col2 / 2), t2 (a,b) WITH (options)
> WHERE t2.a > 4;

How would you express a join condition with that syntax?

> This looks easy to remember, since it compares to:
>
>  CREATE INDEX idx_name ON t2(a,b) WITH (options) WHERE t2.a > 4;
>
> Or am I'm missing something?

Sadly yes, you are, and it's not the first time.

I seem to remember mentioning this to you already in [1].

Please, can you read over [2], it mentions exactly what you're
proposing and why it's not any good.

[1] https://www.postgresql.org/message-id/CAKJS1f9HMeT+7adicEaU8heOMpOB5pKkCVYZLiEZje3DVutVPw@mail.gmail.com
[2] https://www.postgresql.org/message-id/CAEZATCUtGR+U5+QTwjHhe9rLG2nguEysHQ5NaqcK=VbJ78VQFA@mail.gmail.com

-- David Rowley                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services