Re: [PROPOSAL] Move all am-related reloption code into src/backend/access/[am-name] and get rid of relopt_kind

Tom Lane wrote:
> Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> writes:
> > Nikolay Shaplov wrote:
> >> Story start from the point that I found out that a.m. can not forbid changing
> >> some of it's reloptions with ALTER INDEX command.
>
> > Hmm, this sounds like a bug to me. In BRIN, if you change the
> > pages_per_range option for an existing index, the current index
> > continues to work because the value used during the last index build is
> > stored in the metapage. Only when you reindex after changing the option
> > the new value takes effect.
>
> > I think Bloom should do likewise.
>
> AFAICT, Bloom *does* do that. The reloptions are only consulted directly
> while initializing the metapage.

Ah, clearly I misunderstood what he was saying.

> I think Nikolay's complaint is essentially that there should be a way
> for an AM to forbid ALTER INDEX if it's not going to support on-the-fly
> changes of a given reloption. That might be a helpful usability
> improvement, but it's only a usability improvement not a bug fix.

I can get behind that idea, but this also says I should get away from
this thread until 10dev opens.

--
Álvaro Herrera http://www.2ndQuadrant.com/
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