Re: Sequence Access Method WIP

On 13 May 2015 at 11:56, Heikki Linnakangas <hlinnaka(at)iki(dot)fi> wrote:

> On 05/13/2015 07:10 AM, Alvaro Herrera wrote:
>
>> Heikki, do you have time to go through this at this point?
>>
>
> I'm afraid I won't :-(. I did intend to, but looking at the calendar, I
> won't have the time to review this thoroughly enough to commit. Sorry.
>
> I haven't looked at the CREATE/DROP ACCESS METHOD FOR SEQUENCE syntax
> patch at all yet.
>
> We discussed using a single amdata column vs. any number of am-specific
> columns. We settled on amdata, but I'm still not 100% convinced that's the
> best approach. Just as a data point, this removes the log_cnt field and
> moves it into amdata in a non-human-readable format. So for someone who
> only uses the local seqam, this just makes things slightly worse. For more
> complicated seqam's, it would be even more important to display the state
> in a human-readable format. Perhaps it's OK that each seqam provides its
> own functions or similar to do that, but I'd like to revisit that decision.
>
> I still don't like the serial_sequenceam GUC. Not sure what to do instead.
> Needs some thought.

This has had around 2 years of thought at this point. I don't agree it
needs more thought.

There is one clear use case for this and it is of benefit to many
distributed architectures.

I don't see what calamity will occur if we commit this. If you don't want a
sequence AM, don't ever use this.

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