Re: Proposal: Commit timestamp - Mailing list pgsql-hackers

From Peter Eisentraut
Subject Re: Proposal: Commit timestamp
Date
Msg-id 200702040916.44380.peter_e@gmx.net
Whole thread Raw
In response to Re: Proposal: Commit timestamp  (Jan Wieck <JanWieck@Yahoo.com>)
Responses Re: Proposal: Commit timestamp  (Jan Wieck <JanWieck@Yahoo.com>)
List pgsql-hackers
Jan Wieck wrote:
> This is all that is needed for last update wins resolution. And as
> said before, the only reason the clock is involved in this is so that
> nodes can continue autonomously when they lose connection without
> conflict resolution going crazy later on, which it would do if they
> were simple counters. It doesn't require microsecond synchronized
> clocks and the system clock isn't just used as a Lamport timestamp.

Earlier you said that "one assumption is that all servers in the 
multimaster cluster are ntp synchronized", which already rung the alarm 
bells in me.  Now that I read this you appear to require 
synchronization not on the microsecond level but on some level.  I 
think that would be pretty hard to manage for an administrator, seeing 
that NTP typically cannot provide such guarantees.

-- 
Peter Eisentraut
http://developer.postgresql.org/~petere/


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