I think Simon Riggs is already working on that idea. This one is fairly easy to implement. I think these are some of the features only a time-stamp based database can implement. I think database standards were formed during the time, when the data consistency was provided with Lock based mechanisms. And moreover i have already committed on the indexes with snapshot and i am still waiting for its approval from hackers. If that does go through, then i need to work on the reverse mapping hash tables, which is really a long task. So i may not be able to take up time-travel now.
if i remember my last talk with Simon correctly the idea is to have timetravel across transactions.
having this feature inside a transaction will not make it into CVS as it is basically of no practical use.
i would suggest to put some effort into making it work across transactions. just saving the snapshot is not enough
here - there are a couple of other things which have to be taken into consideration (transaction wraparound, etc.)
if you want to work on timetravel my team and i can provide some assistance as we wanted to help in this area anyway.
best regards,
hans
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