[ZODB-Dev] Re: [Persistence-sig] "Straw Man" transaction API

[Phillip J. Eby]

At 09:11 AM 8/1/02 -0400, Barry A. Warsaw wrote:
>
>>>>>> "PJE" == Phillip J Eby <pje@telecommunity.com> writes:
>
>    PJE> The one DBMS whose savepoint implementation I'm sufficiently
>    PJE> familiar with to try and figure this out, won't allow this.
>    PJE> You can only have one savepoint.
>
>Do you mean you can only have one savepoint in total?

I meant, active at a given point in time; that is, there is only one
savepoint at any given moment that you can roll back to.

But it turns out I misspoke, at least in relation to Sybase 12.5.  I just
rechecked the manual and it appears to allow rolling back to arbitrary
named savepoints.  I'm not sure why I thought this wasn't the case,
although perhaps I am thinking of an older version.  I haven't been working
with 12.5 long.

I think I'm going to go back and look at the manuals for some of the other
databases I'm using or plan to use in future, and verify what nesting or
savepoint capabilities they have.  It seems to me that one could simulate
savepoints through the use of nested transactions, or vice versa.  I'll
also take a look at JDBC's metadata variables for transactions, to get an
idea of what variations of capabilities are likely to be out there.

After I've got a better idea of what the different DB's do or don't support
in this area, I'll comment again.  :)