Re: Sequence Access Method WIP

On 08/11/14 00:57, Petr Jelinek wrote:
> On 08/11/14 00:45, Robert Haas wrote:
>> On Nov 5, 2014, at 5:43 PM, Petr Jelinek <petr@2ndquadrant.com> wrote:
>>> I don't see how to make that work with ALTER SEQUENCE USING to be
>>> honest and I do care quite a lot about that use-case (I think the
>>> ability to convert the "local" sequences to 3rd party ones and back
>>> is very important).
>>
>> What specific problems do you foresee?  There's an issue if something
>> depends on one of the added sequence columns, but if that is the case
>> then you had *better* fail.
>>
>> I think that the debugability value of making extra sequence columns
>> human-readable is quite high.
>>
>
> My main problem is actually not with having tuple per-seqAM, but more
> with the fact that Heikki does not want to have last_value as compulsory
> column/parameter. How is the new AM then supposed to know where to pick
> up and if it even can pick up?
>

And obviously, once the last_value is part of the compulsory columns we 
again have to WAL log all the time for the use-case which Heikki is 
using as model, so it does not help there (just to clear what my point 
was about).


--  Petr Jelinek                  http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training &
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