Re: Index Skip Scan - attempting to evalutate patch

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Wednesday, June 26, 2019 1:07 PM, Dmitry Dolgov <9erthalion6(at)gmail(dot)com> wrote:

> > On Wed, Jun 26, 2019 at 1:53 PM pguser pguser(at)diorite(dot)uk wrote:
> > If I apply the latest patch (which says 1 of 2? - maybe I'm missing a part of the patch?), I apply with
>
> Hi,
>
> First of all, thanks for evaluation!
>

No problem. I'd like to get involved in helping this patch mature as I think that we're suffering in a few areas of performance due to this.

> Could you by any change provide also relations schema that were supposed to be
> described by this command?

Okay for now, it's not much. I get the issue of the SIGSEGV on a brand new database with only one relation:

This is with the 12beta2 as compiled from git sources by me:

psql (12beta2)
Type "help" for help.

db2=> \d
List of relations
Schema | Name | Type | Owner
--------+------+-------+-------
e5 | t1 | table | e5
(1 row)

db2=> \d t1
Table "e5.t1"
Column | Type | Collation | Nullable | Default
--------+-------------------+-----------+----------+---------
n1 | smallint | | |
n2 | smallint | | |
c1 | character varying | | |
c2 | character varying | | |
Indexes:
"i1" btree (n1, n2, c1)

And with patch 20 applied:

psql (12beta2)
Type "help" for help.

db2=> \d
psql: server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!> \q
[postgres(at)ip-172-31-33-89 ~]$ . sql2
psql (12beta2)
Type "help" for help.

db2=> \d t1
psql: server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!> \q

In fact, if I do:

createdb db3
psql -d db3
db3=# \d
psql: server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.

I get this on empty database with no relations yet defined.

I feel I have done something silly or missed something when applying patch