Re: Index Skip Scan

2019-06-22 Thread Peter Geoghegan
On Sat, Jun 22, 2019 at 3:15 PM Floris Van Nee wrote: > Perhaps a question: when stepping through code in GDB, is there an easy way > to pretty print for example the contents on an IndexTuple? I saw there's some > tools out there that can pretty print plans, but viewing tuples is more > complic

Re: Index Skip Scan

2019-06-22 Thread Floris Van Nee
> Thanks for testing! You're right, looks like in the current implementation in > case of backwards scan there is one unnecessary extra step forward. It seems > this mistake was made, since I was concentrating only on the backward scans > with a cursor, and used not exactly correct approach to wra

Re: [PATCH] Stop ALTER SYSTEM from making bad assumptions

2019-06-22 Thread Stephen Frost
Greetings, On Sat, Jun 22, 2019 at 17:43 Amit Kapila wrote: > On Sun, Jun 23, 2019 at 2:43 AM Stephen Frost wrote: > > > > Greetings, > > > > On Sat, Jun 22, 2019 at 17:07 Amit Kapila > wrote: > >> > >> On Fri, Jun 21, 2019 at 8:15 PM Robert Haas > wrote: > >> > > >> > On Mon, Jun 17, 2019 at

Re: [PATCH] Stop ALTER SYSTEM from making bad assumptions

2019-06-22 Thread Amit Kapila
On Sun, Jun 23, 2019 at 2:43 AM Stephen Frost wrote: > > Greetings, > > On Sat, Jun 22, 2019 at 17:07 Amit Kapila wrote: >> >> On Fri, Jun 21, 2019 at 8:15 PM Robert Haas wrote: >> > >> > On Mon, Jun 17, 2019 at 10:50 AM Ian Barwick >> > wrote: >> > > In Pg12, the code in pg_basebackup implies

Re: [PATCH] Stop ALTER SYSTEM from making bad assumptions

2019-06-22 Thread Stephen Frost
Greetings, On Sat, Jun 22, 2019 at 17:07 Amit Kapila wrote: > On Fri, Jun 21, 2019 at 8:15 PM Robert Haas wrote: > > > > On Mon, Jun 17, 2019 at 10:50 AM Ian Barwick > > wrote: > > > In Pg12, the code in pg_basebackup implies the correct thing to do is > append to .auto.conf, > > > but as demo

Re: [PATCH] Stop ALTER SYSTEM from making bad assumptions

2019-06-22 Thread Amit Kapila
On Fri, Jun 21, 2019 at 10:31 PM Stephen Frost wrote: > * Tom Lane (t...@sss.pgh.pa.us) wrote: > > > If anybody does complain, my first reaction would be to make ALTER > > SYSTEM strip all comment lines too. > > Uh, I believe it already does? > Yeah, I also think so. -- With Regards, Amit Kapil

Re: [PATCH] Stop ALTER SYSTEM from making bad assumptions

2019-06-22 Thread Amit Kapila
On Fri, Jun 21, 2019 at 8:15 PM Robert Haas wrote: > > On Mon, Jun 17, 2019 at 10:50 AM Ian Barwick > wrote: > > In Pg12, the code in pg_basebackup implies the correct thing to do is > > append to .auto.conf, > > but as demonstrated that can cause problems with duplicate entries. > > Yeah. > > T

Re: \describe*

2019-06-22 Thread Corey Huinker
> > > So what is the uptake on implementing this at the server side, ie. > > DESCRIBE? > > I'm pretty skeptical of this idea, unless you are willing to throw > away at least one and possibly both of the following goals: > > 1. Compatibility with psql's existing \d behavior. > I don't think *compat

Re: Index Skip Scan

2019-06-22 Thread Dmitry Dolgov
> On Sat, Jun 22, 2019 at 12:17 PM Floris Van Nee wrote: > The following sql statement seems to have incorrect results - some logic in > the backwards scan is currently not entirely right. Thanks for testing! You're right, looks like in the current implementation in case of backwards scan there i

Re: Choosing values for multivariate MCV lists

2019-06-22 Thread Tomas Vondra
On Fri, Jun 21, 2019 at 08:50:33AM +0100, Dean Rasheed wrote: On Thu, 20 Jun 2019 at 23:35, Tomas Vondra wrote: On Thu, Jun 20, 2019 at 06:55:41AM +0100, Dean Rasheed wrote: >I'm not sure it's easy to justify ordering by Abs(freq-base_freq)/freq >though, because that would seem likely to put

Re: Index Skip Scan

2019-06-22 Thread Floris Van Nee
The following sql statement seems to have incorrect results - some logic in the backwards scan is currently not entirely right. -Floris drop table if exists a; create table a (a int, b int, c int); insert into a (select vs, ks, 10 from generate_series(1,5) vs, generate_series(1, 1) ks); cr