Re: committing inside cursor loop - Mailing list pgsql-hackers

From Peter Eisentraut
Subject Re: committing inside cursor loop
Date
Msg-id 4ab5df79-140a-23f8-879a-94d5c4978be3@2ndquadrant.com
Whole thread Raw
In response to Re: committing inside cursor loop  (Ildus Kurbangaliev <i.kurbangaliev@postgrespro.ru>)
Responses Re: committing inside cursor loop  (Ildus Kurbangaliev <i.kurbangaliev@postgrespro.ru>)
List pgsql-hackers
On 3/6/18 07:48, Ildus Kurbangaliev wrote:
> Although as was discussed before it seems inconsistent without ROLLBACK
> support. There was a little discussion about it, but no replies. Maybe
> the status of the patch should be changed to 'Waiting on author' until
> the end of discussion.

I'm wondering what the semantics of it should be.

For example, consider this:

drop table test1;
create table test1 (a int, b int);
insert into test1 values (1, 11), (2, 22), (3, 33);

do
language plpgsql
$$
declare
  x int;
begin
  for x in update test1 set b = b + 1 where b > 20 returning a loop
    raise info 'x = %', x;
    if x = 2 then
       rollback;
    end if;
  end loop;
end;
$$;

The ROLLBACK call in the first loop iteration undoes the UPDATE command
that drives the loop.  Is it then sensible to continue the loop?

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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