Re: Add Pipelining support in psql

Hello,

After commit 2cce0fe on master

When executing query:
psql postgres <<EOF
CREATE TABLE psql_pipeline();
\startpipeline
COPY psql_pipeline FROM STDIN;
SELECT 'val1';
\syncpipeline
\getresults
EOF

ERROR:  unexpected message type 0x50 during COPY from stdin
CONTEXT:  COPY psql_pipeline, line 1
Pipeline aborted, command did not run
psql: common.c:1510: discardAbortedPipelineResults: Assertion `res ==
((void *)0) || result_status == PGRES_PIPELINE_ABORTED' failed.
Aborted (core dumped)

The psql crashes with the stack trace:
(gdb) bt
#0  __pthread_kill_implementation (no_tid=0, signo=6,
threadid=<optimized out>) at ./nptl/pthread_kill.c:44
#1  __pthread_kill_internal (signo=6, threadid=<optimized out>) at
./nptl/pthread_kill.c:78
#2  __GI___pthread_kill (threadid=<optimized out>, signo=signo(at)entry=6)
at ./nptl/pthread_kill.c:89
#3  0x0000760edd24527e in __GI_raise (sig=sig(at)entry=6) at
../sysdeps/posix/raise.c:26
#4  0x0000760edd2288ff in __GI_abort () at ./stdlib/abort.c:79
#5  0x0000760edd22881b in __assert_fail_base (fmt=0x760edd3d01e8
"%s%s%s:%u: %s%sAssertion `%s' failed.\n%n",
    assertion=assertion(at)entry=0x5ba46ab79850 "res == ((void *)0) ||
result_status == PGRES_PIPELINE_ABORTED", file=file(at)entry=0x5ba46ab6fcad
"common.c",
    line=line(at)entry=1510, function=function(at)entry=0x5ba46ab9c780
<__PRETTY_FUNCTION__.3> "discardAbortedPipelineResults") at
./assert/assert.c:96
#6  0x0000760edd23b517 in __assert_fail
(assertion=assertion(at)entry=0x5ba46ab79850 "res == ((void *)0) ||
result_status == PGRES_PIPELINE_ABORTED",
    file=file(at)entry=0x5ba46ab6fcad "common.c", line=line(at)entry=1510,
    function=function(at)entry=0x5ba46ab9c780 <__PRETTY_FUNCTION__.3>
"discardAbortedPipelineResults") at ./assert/assert.c:105
#7  0x00005ba46ab2bd40 in discardAbortedPipelineResults () at common.c:1510
#8  ExecQueryAndProcessResults (query=query(at)entry=0x5ba4a2ec1e10 "SELECT
'val1';", elapsed_msec=elapsed_msec(at)entry=0x7ffeb07262a8,
    svpt_gone_p=svpt_gone_p(at)entry=0x7ffeb07262a7,
is_watch=is_watch(at)entry=false, min_rows=min_rows(at)entry=0,
opt=opt(at)entry=0x0, printQueryFout=0x0)
    at common.c:1811
#9  0x00005ba46ab2983f in SendQuery (query=0x5ba4a2ec1e10 "SELECT
'val1';") at common.c:1212
#10 0x00005ba46ab3f66a in MainLoop (source=source(at)entry=0x760edd4038e0
<_IO_2_1_stdin_>) at mainloop.c:515
#11 0x00005ba46ab23f2a in process_file (filename=0x0,
use_relative_path=use_relative_path(at)entry=false) at command.c:4870
#12 0x00005ba46ab1e9d9 in main (argc=<optimized out>,
argv=0x7ffeb07269d8) at startup.c:420

06.03.2025 11:20, Michael Paquier пишет:
> On Wed, Mar 05, 2025 at 03:25:12PM +0100, Daniel Verite wrote:
>> Anthonin Bonnefoy wrote:
>>> I do see the idea to make it easier to convert existing scripts into
>>> using pipelining. The main focus of the initial implementation was
>>> more on protocol regression tests with psql, so that's not necessarily
>>> something I had in mind.
>> Understood. Yet pipelining can accelerate considerably certain scripts
>> when client-server latency is an issue. We should expect end users to
>> benefit from it too.
> That was not a test case we had in mind originally here, but if it is
> possible to keep the implementation simple while supporting your
> demand, well, let's do it. If it's not that straight-forward, let's
> use the new meta-command, forbidding \g and \gx based on your
> arguments from upthread.
> --
> Michael