Re: POC: postgres_fdw insert batching - Mailing list pgsql-hackers

From Zhihong Yu
Subject Re: POC: postgres_fdw insert batching
Date
Msg-id CALNJ-vRJOC5Sbt7LwFbyP4d9bPJurEyrxTz01EaxypdniG8PiA@mail.gmail.com
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In response to RE: POC: postgres_fdw insert batching  ("tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com>)
Responses RE: POC: postgres_fdw insert batching  ("tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com>)
List pgsql-hackers
Hi, Takayuki-san:

+           if (batch_size <= 0)
+               ereport(ERROR,
+                       (errcode(ERRCODE_SYNTAX_ERROR),
+                        errmsg("%s requires a non-negative integer value",

It seems the message doesn't match the check w.r.t. the batch size of 0.

+   int         numInserted = numSlots;

Since numInserted is filled by ExecForeignBatchInsert(), the initialization can be done with 0.

Cheers

On Sun, Jan 17, 2021 at 10:52 PM tsunakawa.takay@fujitsu.com <tsunakawa.takay@fujitsu.com> wrote:
Tomas-san,

From: Amit Langote <amitlangote09@gmail.com>
> Good thing you reminded me that this is about inserts, and in that
> case no, ExecInitModifyTable() doesn't know all leaf partitions, it
> only sees the root table whose batch_size doesn't really matter.  So
> it's really ExecInitRoutingInfo() that I would recommend to set
> ri_BatchSize; right after this block:
>
> /*
>  * If the partition is a foreign table, let the FDW init itself for
>  * routing tuples to the partition.
>  */
> if (partRelInfo->ri_FdwRoutine != NULL &&
>     partRelInfo->ri_FdwRoutine->BeginForeignInsert != NULL)
>     partRelInfo->ri_FdwRoutine->BeginForeignInsert(mtstate, partRelInfo);
>
> Note that ExecInitRoutingInfo() is called only once for a partition
> when it is initialized after being inserted into for the first time.
>
> For a non-partitioned targets, I'd still say set ri_BatchSize in
> ExecInitModifyTable().

Attached is the patch that added call to GetModifyBatchSize() to the above two places.  The regression test passes.

(FWIW, frankly, I prefer the previous version because the code is a bit smaller...  Maybe we should refactor the code someday to reduce similar processings in both the partitioned case and non-partitioned case.)


Regards
Takayuki Tsunakawa

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