[fdo-internals] Motion: RFC 3 - PostGIS provider

Paul Ramsey pramsey at refractions.net
Tue May 8 12:59:01 EDT 2007

In that case, PostgreSQL has all the facility needed to support the FDO.


Orest Halustchak wrote:
> I don't think that save points would work the way we'd expect a regular
> transaction to work. A save point is within a transaction and while you
> can roll back to a save point, you can't really commit at a save point
> except by committing the transaction that includes it.
> Again, we're talking about short transactions in this case, not long
> transactions.
> Basically, fdo expects the standard short transaction mechanism. It's
> not a nested transaction concept. You can execute any set of data update
> operations and they will be isolated from other users until a
> transaction commit. At that time, the edits are permanent and other
> users can see them. A rollback will remove all edits done since the
> beginning of the transaction. A short transaction supports ACID
> properties (atomicity, consistency, isolation, and durability).
> Thanks,
> Orest.
> -----Original Message-----
> From: fdo-internals-bounces at lists.osgeo.org
> [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Paul Ramsey
> Sent: Tuesday, May 08, 2007 12:38 PM
> To: FDO Internals Mail List
> Subject: Re: [fdo-internals] Motion: RFC 3 - PostGIS provider
> Jason Birch wrote:
>> PostgreSQL doesn't currently support nested transactions.  Mateusz has
>> been using "soft" transactions internally to ensure per-action 
>> consistency, so if we support explicit transactions he will have to 
>> somehow test for existing transaction before starting internal 
>> transactions.
> Not knowing how FDO is actually exercising the database or what contract
> it expects, I will blindly ask: is it possible that savepoints do what
> FDO needs done?
> http://www.postgresql.org/docs/8.0/interactive/sql-savepoint.html


   Paul Ramsey
   Refractions Research
   pramsey at refractions.net
   Phone: 250-383-3022
   Cell: 250-885-0632

More information about the fdo-internals mailing list