Re: ALTER TABLE ADD COLUMN fast default - Mailing list pgsql-hackers

From David Rowley
Subject Re: ALTER TABLE ADD COLUMN fast default
Date
Msg-id CAKJS1f-tnAcD0whHcGyZVPGRrJoCPo9ZajtEFV2BDgCwKP+DVw@mail.gmail.com
Whole thread Raw
In response to Re: ALTER TABLE ADD COLUMN fast default  (Andrew Dunstan <andrew.dunstan@2ndquadrant.com>)
Responses Re: ALTER TABLE ADD COLUMN fast default  (David Rowley <david.rowley@2ndquadrant.com>)
List pgsql-hackers
On 8 March 2018 at 18:40, Andrew Dunstan <andrew.dunstan@2ndquadrant.com> wrote:
>  select * from t;
>  fastdef tps = 107.145811
>  master  tps = 150.207957
>
> "select * from t" used to be about a wash, but with this patch it's
> got worse. The last two queries were worse and are now better, so
> that's a win.

How does it compare to master if you drop a column out the table?
Physical tlists will be disabled in that case too. I imagine the
performance of master will drop much lower than the all columns
missing case.



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


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