Re: Fillfactor for GIN indexes

On Sat, Jan 17, 2015 at 4:49 AM, Alexander Korotkov
<aekorotkov(at)gmail(dot)com> wrote:
> I already wrote quite detailed explanation of subject. Let mel try to
> explain in shortly. GIN is two level nested btree. Thus, GIN would have
> absolutely same benefits from fillfactor as btree. Lack of tests showing it
> is, for sure, fault.
>
> However, GIN posting trees are ordered by ItemPointer and this makes some
> specific. If you have freshly created table and do inserts/updates they
> would use the end of heap. Thus, inserts would go to the end of GIN posting
> tree and fillfactor wouldn't affect anything. Fillfactor would give benefits
> on HOT or heap space re-usage.

Ah, OK. Those tests clarify things considerably; I see the point now.

--
Robert Haas
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