Re: the big picture for index-only scans

On Tue, May 10, 2011 at 8:19 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> Robert Haas wrote:
>> >> Any thoughts welcome. ?Incidentally, if anyone else feels like working
>> >> on this, feel free to let me know and I'm happy to step away, from all
>> >> of it or from whatever part someone else wants to tackle. ?I'm mostly
>> >> working on this because it's something that I think we really need to
>> >> get done, more than having a burning desire to be the one who does it.
>> >
>> > Indexonly scans are welcome!
>> > I believe I can help on 3 and 4, but (really) not sure for 1 and 2.
>>
>> Well, I have code for #1, and just need reviews, and #2 shouldn't be
>> that hard, and with luck I'll twist Bruce's arm into doing it (*waves
>> to Bruce*).  So #3 and #4 are the next thing to tackle.  Any thoughts
>> on what/how you'd like to contribute there?
>
> I am happy to have pg_upgrade skip upgrading visibility map files --- it
> already has code to conditionally process them because they only exist
> in >= 8.4:
>
>        /* fsm/vm files added in PG 8.4 */
>        if (GET_MAJOR_VERSION(old_cluster.major_version) >= 804)
>        {
>            /*
>             * Copy/link any fsm and vm files, if they exist
>             */
>
> Just give the word and it will be done.

I hereby give the word. :-)

Specifically, we need to skip copying vm files (only) if coming from a
version prior to this commit:

http://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=e16954f3d27fa8e16c379ff6623ae18d6250a39c

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company