Re: Suggestion to add --continue-client-on-abort option to pgbench

On Thu, 13 Nov 2025 18:17:37 +0800
Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com> wrote:

>
>
> > On Nov 13, 2025, at 17:40, Yugo Nagata <nagata(at)sraoss(dot)co(dot)jp> wrote:
> >
> > The following script:
> >
> > \startpipeline
> > <queries list 1>
> > \syncpipeline
> > <queries list 2>
> > \endpipeline
> >
> > can be considered equivalent to:
> >
> > BEGIN;
> > <queries list 1>
> > END;
> > BEGIN;
> > <queries list 2>
> > END;
>
> This looks like that every \sysnpipeline will start a new transaction, is that true?

Yes, it causes a new transaction to start.
In a pipeline, an implicit transaction block is started, and \syncpipeline closes it.
Then, a new implicit transaction begins.

Here’s a simple example to illustrate this:

$ cat pipeline_tx.sql
drop table if exists tbl;
create table tbl (i int);
\startpipeline
insert into tbl values(1);
insert into tbl values(2);
\syncpipeline
insert into tbl values(3);
insert into tbl values(4);
\endpipeline
$ pgbench -f pipeline_tx.sql -t 1 -M extended -n > /dev/null
$ psql -c "select xmin, i from tbl"
xmin | i
------+---
1268 | 1
1268 | 2
1269 | 3
1269 | 4
(4 rows)

Regards,
Yugo Nagata

--
Yugo Nagata <nagata(at)sraoss(dot)co(dot)jp>