Re: [PATCH] Better Performance for PostgreSQL with large INSERTs

[Filip Janus]

Hi,
7% is an interesting improvement for these cases. I see it as a nice
feature,
What about adding a GUC variable to have the ability to configure
PQ_RECV_BUFFER_SIZE based on the user's needs?

    -Filip-


út 30. 9. 2025 v 10:42 odesílatel Philipp Marek <phil...@marek.priv.at>
napsal:

> Here's the patch again, this time with a 128kB buffer size.
>
> This gives us nearly the same gains (~7%) for the blob INSERTs,
> and the additional memory usage (120kB) shouldn't really matter,
> with "temp_buffer"s 8MB and "work_mem" 4MB defaults.
>
> Making it configurable would give a much more complex patch --
> so I suggest just using this fixed size.
>
>
> Thanks!
>
>
> diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
> index 25f739a6..72d092b2 100644
> --- a/src/backend/libpq/pqcomm.c
> +++ b/src/backend/libpq/pqcomm.c
> @@ -117,7 +117,7 @@ static List *sock_paths = NIL;
>    */
>
>   #define PQ_SEND_BUFFER_SIZE 8192
> -#define PQ_RECV_BUFFER_SIZE 8192
> +#define PQ_RECV_BUFFER_SIZE (128 * 1024)
>
>   static char *PqSendBuffer;
>   static int     PqSendBufferSize;       /* Size send buffer */
>
>
>