From: Brar Piening <brar@gmx.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
To: mike.adelson314@gmail.com
Cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #16988: Spurious "SET LOCAL can only be used in transaction blocks" warning using implicit transaction block
Date: Sun, 2 May 2021 00:22:44 +0200
Message-ID: <3a158f8d-708e-ad13-617a-af8349aae4f4@gmx.de> (raw)
In-Reply-To: <3044772.1619712195@sss.pgh.pa.us>
References: <16988-58edba102adb5128@postgresql.org>
<3044772.1619712195@sss.pgh.pa.us>
Tom Lane wrote:
> PG Bug reporting form <noreply@postgresql.org> writes:
>> I am using SET LOCAL in an Npgsql multi-statement command.
> It seems that whatever Npgsql is doing at the wire protocol level
> doesn't match this, but they'd have to explain what they are doing
> for us to offer much help.
>
At the wire protocol level npgsql sends this as two queries via the
extended query protocol without a sync inbetween them.
(Parse,Bind,Describe,Execute;Parse,Bind,Describe,Execute,Sync)
You can use the following short libpq program to reproduce it in PG14
(for brevity I've omitted any error checking):
#include <libpq-fe.h>
int
main(int argc,char **argv)
{
PGconn* conn;
PGresult* res;
conn =PQconnectdb("");
PQenterPipelineMode(conn);
PQsendQueryParams(conn,"SET LOCAL work_mem = 100;",0,NULL,NULL,NULL,NULL,1);
PQsendQueryParams(conn,"SHOW work_mem;",0,NULL,NULL,NULL,NULL,1);
PQpipelineSync(conn);
res =PQgetResult(conn);// SET LOCAL => PGRES_COMMAND_OK
PQclear(res);
PQgetResult(conn);// NULL
res =PQgetResult(conn);// SHOW => PGRES_TUPLES_OK
fprintf(stdout,"%s\n",PQgetvalue(res,0,0));
PQclear(res);
PQgetResult(conn);// NULL
res =PQgetResult(conn);// PGRES_PIPELINE_SYNC
PQclear(res);
PQfinish(conn);
return 0;
}
Regards,
Brar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-bugs@postgresql.org
Cc: brar@gmx.de, tgl@sss.pgh.pa.us, mike.adelson314@gmail.com, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #16988: Spurious "SET LOCAL can only be used in transaction blocks" warning using implicit transaction block
In-Reply-To: <3a158f8d-708e-ad13-617a-af8349aae4f4@gmx.de>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox