Re: Parallel copy - Mailing list pgsql-hackers

From vignesh C
Subject Re: Parallel copy
Date
Msg-id CALDaNm1ZhpYFNDG5xwkGNCqnJ3EkpV6z1NU=jdLm1XtVYagNMw@mail.gmail.com
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In response to RE: Parallel copy  ("Hou, Zhijie" <houzj.fnst@cn.fujitsu.com>)
Responses RE: Parallel copy
List pgsql-hackers
On Mon, Dec 7, 2020 at 3:00 PM Hou, Zhijie <houzj.fnst@cn.fujitsu.com> wrote:
>
> > Attached v11 patch has the fix for this, it also includes the changes to
> > rebase on top of head.
>
> Thanks for the explanation.
>
> I think there is still chances we can know the size.
>
> +                * line_size will be set. Read the line_size again to be sure if it is
> +                * completed or partial block.
> +                */
> +               dataSize = pg_atomic_read_u32(&lineInfo->line_size);
> +               if (dataSize != -1)
> +               {
>
> If I am not wrong, this seems the branch that procsssing the populated block.
> I think we can check the copiedSize here, if copiedSize == 0, that means
> Datasizes is the size of the whole line and in this case we can do the enlarge.
>
>

Yes this optimization can be done, I will handle this in the next patch set.

Regards,
Vignesh
EnterpriseDB: http://www.enterprisedb.com



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