Re: POC: postgres_fdw insert batching

Tsunakawa-san,

On Tue, Jan 19, 2021 at 12:50 PM tsunakawa.takay@fujitsu.com
<tsunakawa.takay@fujitsu.com> wrote:
> From: Tomas Vondra <tomas.vondra@enterprisedb.com>
> > OK. Can you prepare a final patch, squashing all the commits into a
> > single one, and perhaps use the function in create_foreign_modify?
>
> Attached, including the message fix pointed by Zaihong-san.

Thanks for adopting my suggestions regarding GetForeignModifyBatchSize().

I apologize in advance for being maybe overly pedantic, but I noticed
that, in ExecInitModifyTable(), you decided to place the call outside
the loop that goes over resultRelations (shown below), although my
intent was to ask to place it next to the BeginForeignModify() in that
loop.

    resultRelInfo = mtstate->resultRelInfo;
    i = 0;
    forboth(l, node->resultRelations, l1, node->plans)
    {
        ...
        /* Also let FDWs init themselves for foreign-table result rels */
        if (!resultRelInfo->ri_usesFdwDirectModify &&
            resultRelInfo->ri_FdwRoutine != NULL &&
            resultRelInfo->ri_FdwRoutine->BeginForeignModify != NULL)
        {
            List       *fdw_private = (List *) list_nth(node->fdwPrivLists, i);

            resultRelInfo->ri_FdwRoutine->BeginForeignModify(mtstate,
                                                             resultRelInfo,
                                                             fdw_private,
                                                             i,
                                                             eflags);
        }

Maybe it's fine today because we only care about inserts and there's
always only one entry in the resultRelations list in that case, but
that may not remain the case in the future.

-- 
Amit Langote
EDB: http://www.enterprisedb.com