Re: WIP: Covering + unique indexes.

On Fri, Jan 22, 2016 at 7:19 AM, Anastasia Lubennikova
<a(dot)lubennikova(at)postgrespro(dot)ru> wrote:
>
> Done. I hope that my patch is close to the commit too.
>

Thanks for the update.

I've run into this problem:

create table foobar (x text, w text);
create unique index foobar_pkey on foobar (x) including (w);
alter table foobar add constraint foobar_pkey primary key using index
foobar_pkey;

ERROR: index "foobar_pkey" does not have default sorting behavior
LINE 1: alter table foobar add constraint foobar_pkey primary key us...
^
DETAIL: Cannot create a primary key or unique constraint using such an index.
Time: 1.577 ms

If I instead define the table as
create table foobar (x int, w xml);

Then I can create the index and then the primary key the first time I
do this in a session. But then if I drop the table and repeat the
process, I get "does not have default sorting behavior" error even for
this index that previously succeeded, so I think there is some kind of
problem with the backend syscache or catcache.

create table foobar (x int, w xml);
create unique index foobar_pkey on foobar (x) including (w);
alter table foobar add constraint foobar_pkey primary key using index
foobar_pkey;
drop table foobar ;
create table foobar (x int, w xml);
create unique index foobar_pkey on foobar (x) including (w);
alter table foobar add constraint foobar_pkey primary key using index
foobar_pkey;
ERROR: index "foobar_pkey" does not have default sorting behavior
LINE 1: alter table foobar add constraint foobar_pkey primary key us...
^
DETAIL: Cannot create a primary key or unique constraint using such an index.

Cheers,

Jeff