Re: New vacuum option to do only freezing

On Fri, Nov 2, 2018 at 2:02 AM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> On Mon, Oct 1, 2018 at 6:23 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> > Attached patch adds a new option FREEZE_ONLY to VACUUM command. This
> > option is same as FREEZE option except for it disables reclaiming dead
> > tuples. That is, with this option vacuum does pruning HOT chain,
> > freezing live tuples and maintaining both visibility map and freespace
> > map but does not collect dead tuples and invoke neither heap vacuum
> > nor index vacuum. This option will be useful if user wants to prevent
> > XID wraparound a table as quick as possible, especially when table is
> > quite large and is about to XID wraparound. I think this usecase was
> > mentioned in some threads but I couldn't find them.
>

Thank you for the comment!

> The feature seems like a reasonable one, but the name doesn't seem
> like a good choice. It doesn't only freeze - e.g. it HOT-prunes, as
> it must. Maybe consider something like (without_index_cleanup true)
> or (index_cleanup false).

Adding a field-and-value style option might be worth. Or maybe we can
add one option for example freeze_without_index_cleanup?

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center