On 13 May 2015 at 11:56, Heikki Linnakangas <hlinnaka@iki.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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Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services