Re: Meaning of transaction in v$transaction

The simple answer to your question is that there is only one entry in v$transaction per transaction regardless of the number of locks acquired, undo blocks used etc.
There is lot of the other info. you mention in various data structures and available through other v$ views etc. thats too long to go into.

Doug C <dcowles_at_i84.net> wrote in message news:<4kvhmt048vqelcvmpbbnuta9iae007mbnm_at_4ax.com>...
> Per a Tom Kyte example..
> This is available at
> http://asktom.oracle.com/pls/ask/f?p=4950:8:37965::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:839412906735,{v$transaction}
>
> The long and the short of it is that if I open a session, and then create a
> situation where I have various locks on 2 tables, I have 2 entries in
> v$transaction.
>
> Per the note : v$transaction contains an entry for every active transaction..
> However - a database transaction is really a unit of work of any number of
> activities atomically commited or rolled back. And I'm using the term in the
> sense of what you might find in a book by C.J. Date for example. In this
> example (the link), there are two entries in v$transaction for one "database
> transaction". If I were to comit, both entries in v$transaction would go away,
> even though in the theoretical sense, it is really one database transaction.
>
> Therefore - can I assume this - If I in the course of a database transaction
> require the creation of different transaction id's, slots in rbs, etc., that
> that will create different points in time for multi-version read consistency, I
> will get a new entry in v$transaction. In other words, is it intrinsically
> tied to the point-in-time that is related to the transaction id that indicates
> this block is in the middle of being used - use the before image - etc.,
> Emphasis on point-in-time
>
> Just checking... just re-phrasing in my own words.
>
> Thanks,
> Doug
Received on Thu Aug 02 2001 - 17:52:10 CDT