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

From Alvaro Herrera
Subject Re: [PROPOSAL] Move all am-related reloption code into src/backend/access/[am-name] and get rid of relopt_kind
Date
Msg-id 20160527202456.GA717848@alvherre.pgsql
Whole thread Raw
In response to Re: [PROPOSAL] Move all am-related reloption code into src/backend/access/[am-name] and get rid of relopt_kind  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Alvaro Herrera <alvherre@2ndquadrant.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/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: [PROPOSAL] Move all am-related reloption code into src/backend/access/[am-name] and get rid of relopt_kind
Next
From: Tom Lane
Date:
Subject: Re: Parallel pg_dump's error reporting doesn't work worth squat