On Thu, Apr 17, 2008 at 12:35:33AM +0800, Craig Ringer wrote: > That's subject to the same issues, because a transaction's > current_timestamp() is determined at transaction start. But clock_timestamp() (and its ancestors in Postgres) don't have that restriction. I dunno that it's enough for you, though, since you have visibility issues as well. You seem to want both the benefits of files and relational database transactions, and I don't think you can really have both at once without paying in reader complication. One way I can think of doing it is to write a seen_log that notes what the client has already seen with a timestamp of (say) 1 minute. Then you can say "go forward from this time excluding ids (ids here)". A
