You are viewing a plain text version of this content. The canonical link for it is here.

Posted to user@drill.apache.org by Aditya Allamraju <ad...@gmail.com> on 2020/05/29 01:12:13 UTC

FetchSize parameter by Drill driver

Team,

Does drillbit understand the "fetchsize" connection parameter used by a
JDBC driver.
I was going through the Drill JDBC driver documentation and there is no
mention about it.

Is there a fixed default value Drill uses for fetchsize?

Thanks
Aditya

Re: FetchSize parameter by Drill driver

Posted by Paul Rogers <pa...@gmail.com>.

Hi Aditya,

Drill works with data in "batches" of value vectors. I believe that the
client has no control over the amount of data in each batch. Instead, the
batch size is set by the top-most operator in the DAG before "screen". The
good news is that Drill does limit batch sizes in most cases. The bad news
is that the limit can't be set (AFAIK) from JDBC.

- Paul

On Thu, May 28, 2020 at 6:12 PM Aditya Allamraju <ad...@gmail.com>
wrote:

> Team,
>
> Does drillbit understand the "fetchsize" connection parameter used by a
> JDBC driver.
> I was going through the Drill JDBC driver documentation and there is no
> mention about it.
>
> Is there a fixed default value Drill uses for fetchsize?
>
> Thanks
> Aditya
>