Re: Question: pg_class attributes and race conditions ? - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Question: pg_class attributes and race conditions ?
Date
Msg-id 20070316205918.GG17953@alvh.no-ip.org
Whole thread Raw
In response to Re: Question: pg_class attributes and race conditions ?  ("Simon Riggs" <simon@2ndquadrant.com>)
Responses Re: Question: pg_class attributes and race conditions ?  ("Simon Riggs" <simon@2ndquadrant.com>)
List pgsql-hackers
Simon Riggs wrote:

> >  What if we only applied
> > HOT to primary-key indexes, so that there was certainly not more than
> > one index per table that the property applies to?
> 
> On its own, I don't think this is a sufficiently wide use-case.
>
> Perhaps we should do this PLUS make HOT-semantics optional for each
> additional index. i.e. HOT is always enforced on primary indexes and
> optionally on other indexes (but not by default).

Here's is a very simple, low-tech idea.  How about checking whether the
new index requires chilling tuples; if it does, then elog(ERROR) until
all the indexes have been manually chilled, which would be done with an
"ALTER INDEX ... CHILL" command or something like that.  Only when all
indexes are known chilled, you can create another one, and then the user
can "hotify" indexes as appropriate.

(Disclaimer: I haven't followed the HOT design closely to know if this
makes enough sense)

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.


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