Re: Avoiding any locks in SQL Servers - read and understand....its magic.

Hi, Brian !

No, you do not create new data. You time - shift all transaction, let them run, as if they are working alone (in reality they work on their own snapshot of database, thank MVCC) and then, before updating the database, you look at the timestamp of other transactions and at the timestamp of updates and rearrange all, as if a lock had been set. Afterwards, you can drop all changes on the snapshot, a clean up. There is some overhead, yes. But that equals by many times the blocks in SQL Server, caused by locks, blocking each other (no deadlocks).

Read about MVTO, its magic...for many SQL programmers, maybe...

regards, Guido Stepken

Brian Peasland wrote:
> Maybe I missed something, and I admit that I don't know that much about
> MVTO. But when you modify data with MVTO, aren't you simply creating
> *new* data? You aren't modifying *old* data. Instead, you are creating a
> new version of the old data. Versioning uses different techniques than
> the techniques required for maintaining transaction consistency in
> non-versioned data. IMO, you can't use versioning and then say that
> locks are not necessary. They may not be necessary in versioned data,
> but they are necessary in non-versioned data if you want to maintain any
> semblance of transaction control and consistency.
>
> Cheers,
> Brian
Received on Mon Aug 18 2003 - 13:38:48 CDT