Horton

Re: Pipeline mode and PQpipelineSync()

Boris Kolpackov <boris@codesynthesis.com>

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From: Boris Kolpackov <boris@codesynthesis.com>
To: Alvaro Herrera <alvaro.herrera@2ndquadrant.com>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2021-06-29T14:14:46Z
Lists: pgsql-hackers 
Alvaro Herrera <alvaro.herrera@2ndquadrant.com> writes:

> No luck reproducing any problems with this sequence as yet.

Can you try to recreate the call flow as implemented here (it's
pretty much plain old C if you ignore error handling):

https://git.codesynthesis.com/cgit/odb/libodb-pgsql/tree/odb/pgsql/statement.cxx?h=bulk#n789

Except replacing `continue` on line 966 with `break` (that will
make the code read-biased which I find triggers the error more
readily, though I was able to trigger it both ways).

Then in an explicit transaction send 500 prepared insert statements
(see previous email for details) with 250'th having a duplicate
primary key.

Commits

  1. libpq: Fix sending queries in pipeline aborted state

  2. Fix libpq state machine in pipeline mode

  3. Add PQsendFlushRequest to libpq