On 12/20/2017 01:45 PM, Konstantin Knizhnik wrote: > I wonder if Postgres community is interested in supporting time travel > queries in PostgreSQL (something like AS OF queries in Oracle: > https://docs.oracle.com/cd/B14117_01/appdev.101/b10795/adfns_fl.htm). > As far as I know something similar is now developed for MariaDB. > > It seems to me that it will be not so difficult to implement them in > Postgres - we already have versions of tuples. > Looks like we only need to do three things: > 1. Disable autovacuum (autovacuum = off) > 2. Enable commit timestamp (track_commit_timestamp = on) > 3. Add asofTimestamp to snapshot and patch XidInMVCCSnapshot to > compare commit timestamps when it is specified in snapshot. >
that sounds really awesome ... i would love to see that. my question is: while MVCC is fine when a tuple is still there ... what are you going to do with TRUNCATE and so on? it is not uncommon that a table is truncated frequently. in this case MVCC won't help. what are your thoughts on this ? many thanks, hans -- Hans-Jürgen Schönig Cybertec Schönig & Schönig GmbH Gröhrmühlgasse 26 A-2700 Wiener Neustadt Web: https://www.cybertec-postgresql.com
