Re: [patch] CLUSTER blocks scanned progress reporting - Mailing list pgsql-hackers

From Matthias van de Meent
Subject Re: [patch] CLUSTER blocks scanned progress reporting
Date
Msg-id CAEze2WiwvfktwML1KRffV3h5idP3ynA=ES9LvddhUojHJQKzCg@mail.gmail.com
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In response to Re: [patch] CLUSTER blocks scanned progress reporting  (Fujii Masao <masao.fujii@oss.nttdata.com>)
Responses Re: [patch] CLUSTER blocks scanned progress reporting  (Fujii Masao <masao.fujii@oss.nttdata.com>)
List pgsql-hackers
On Thu, 26 Nov 2020 at 00:55, Fujii Masao <masao.fujii@oss.nttdata.com> wrote:
>
> +                                * A heap scan need not return tuples for the last page it has
> +                                * scanned. To ensure that heap_blks_scanned is equivalent to
> +                                * total_heap_blks after the table scan phase, this parameter
> +                                * is manually updated to the correct value when the table scan
> +                                * finishes.
>
> So it's better to update this comment a bit? For example,
>
>      If the scanned last pages are empty, it's possible to go to the next phase
>      while heap_blks_scanned != heap_blks_total. To ensure that they are
>      equivalet after the table scan phase, this parameter is manually updated
>      to the correct value when the table scan finishes.
>

PFA a patch with updated message and comment. I've reworded the
messages to specifically mention empty pages and the need for setting
heap_blks_scanned = total_heap_blks explicitly.

Feel free to update the specifics, other than that I think this is a
complete fix for the issues at hand.

Regards,

Matthias van de Meent

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