Talk:Multiversion concurrency control
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Merging is impossible! MVCC is a different term it, there are many MVCC systems but only few are integrated with timestamp CC. Many of them are working with two-phase locking (2PL) to reduce shared-locks.
There are at least two kinds of MVCC using 2PL (Oracle merged, Postgres) and using timestamps (also Oracle?). One can say that MVCC extends both CC methods to eliminate read limits. Also pure timestamp CC does not store versions but only detects conflicts based on timestamps and restarts transaction. source1 source2 --Adie 20:16, 3 August 2005 (UTC)
Also see Multi-Version_Concurrency_Control. Looks like a better candidate for merging :-).Nicolas Barbier 20:27, 26 October 2005 (UTC)
- Agreed. I've made the change. Personally, I think this article is more technical than it needs to be. Perhaps use the first (and only paragraph) from the other page, plus the last from this one? Turnstep 23:34, 26 October 2005 (UTC)
[edit] Snapshots, MVCC, and docs
User:Tarvin added this:
- The documentation for some DBMSes use the Snapshot Isolation term for Multiversion Concurrency Control.
Can you give a precise citation, please? Because if this is true then the docs are wrong. MVCC can be used to implement snapshots, but it's not synonymous with that isolation level any more than 2PL is. So if it's true that they state this then the article should probably clarify that it's a misstatement. --Craig Stuntz 21:25, 8 February 2006 (UTC)
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- You are right: MVCC can be used to implement Snapshot Isolation (SI). I've removed the disputed sentence from the page for now.
- I just thought that SI should be mentioned on the page, because it's in instance of MVCC.
- TroelsArvin 22:26, 8 February 2006 (UTC)
- I stuck in a mention. See what you think and feel free to edit. --Craig Stuntz 14:47, 9 February 2006 (UTC)
