From: Bharath Rupireddy <bharath.rupireddyforpostg...@gmail.com> Sent: Wednesday, May 26, 2021 9:56 PM > On Wed, May 26, 2021 at 6:36 PM Tomas Vondra > <tomas.von...@enterprisedb.com> wrote: > > > > On 5/26/21 8:57 AM, Bharath Rupireddy wrote: > > > On Tue, May 25, 2021 at 2:47 PM Bharath Rupireddy > > > <bharath.rupireddyforpostg...@gmail.com> wrote: > > >> > > >> On Tue, May 25, 2021 at 1:08 PM houzj.f...@fujitsu.com > > >> <houzj.f...@fujitsu.com> wrote: > > >>> Thanks for the comments. I have addressed all comments to the v3 > patch. > > >> > > >> Thanks! The patch basically looks good to me except that it is > > >> missing a commit message. I think it can be added now. > > > > > > With v3 patch, I observed failure in postgres_fdw test cases with > > > insert query in prepared statements. Root cause is that in > > > postgresGetForeignModifyBatchSize, fmstate can be null (see the > > > existing code which handles for fmstate null cases). I fixed this, > > > and added a commit message. PSA v4 patch. > > > > > > > Thanks. In what situation is the fmstate NULL? If it is NULL, the > > current code simply skips the line adjusting it. Doesn't that mean we > > may not actually fix the bug in that case? > > fmstate i.e. resultRelInfo->ri_FdwState is NULL for EXPLAIN without ANALYZE > cases, below comment says it and we can't get the bug because we don't > actually execute the insert statement. The bug occurs on the remote server > when the insert query with those many query parameters is submitted to the > remote server.
Agreed. The "ri_FdwState" is initialized in postgresBeginForeignInsert or postgresBeginForeignModify. I think the above functions are always invoked before getting the batch_size. Only in EXPLAIN mode, it will not initialize the ri_FdwState. /* * Do nothing in EXPLAIN (no ANALYZE) case. resultRelInfo->ri_FdwState * stays NULL. */ if (eflags & EXEC_FLAG_EXPLAIN_ONLY) return; Best regards, houzj