Re: Sequence Access Method WIP

On 18 November 2013 07:36, Heikki Linnakangas <hlinnakangas@vmware.com> wrote:
> On 14.11.2013 22:10, Simon Riggs wrote:
>>
>> Includes test extension which allows sequences without gaps - "gapless".
>
>
> I realize this is just for demonstration purposes, but it's worth noting
> that it doesn't actually guarantee that when you use the sequence to
> populate a column in the table, the column would not have gaps. Sequences
> are not transactional, so rollbacks will still produce gaps. The
> documentation is misleading on that point. Without a strong guarantee, it's
> a pretty useless extension.

True.

If I fix that problem, I should change the name to "lockup" sequences,
since only one transaction at a time could use the nextval.

Should I change the documentation, or just bin the idea?

-- Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services