Re: Proposal: Select ... AS OF Savepoint - Mailing list pgsql-hackers

From Hans-Juergen Schoenig
Subject Re: Proposal: Select ... AS OF Savepoint
Date
Msg-id F4EC6589-8919-4198-B770-BC6AD6670310@cybertec.at
Whole thread Raw
In response to Re: Proposal: Select ... AS OF Savepoint  ("Gokulakannan Somasundaram" <gokul007@gmail.com>)
Responses Re: Proposal: Select ... AS OF Savepoint
Re: Proposal: Select ... AS OF Savepoint
List pgsql-hackers

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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