Using an externally hosted postGreSQL as a gnu cash backend?

[John Ralls]

> On Apr 11, 2016, at 3:39 PM, Michael Wagner <mikepwagner at mikepwagner.net> wrote:
> 
> On Mon, Apr 11, 2016 at 6:12 PM, Russell Mercer <rmercer206 at gmail.com>
> wrote:
> 
>> Mike,
>> 
>> I think there are a couple of things at play here.
>> 
>> 1.  Using a database backend as opposed to the .xml file:  There are noted
>> issues with data consistency when using any backend storage aside from the
>> .xml.  The issues may not be major, and may only apply in certain areas
>> like business functions, but that has not been quantified.  In short, there
>> are known data integrity issues, but their scope and severity are not known
>> as they pertain to any or all database backends.  That is one primary
>> reason other people on the list have recommended against using it.
>> 
> 
> Is there a nickel tour of the data consistency issues? I did a quick web
> search and didn't find anything.
> 
> 
>> 
>> 2.  Postgres data integrity, ACID support, etc.  I use Postgres on a daily
>> basis for my work, so I completely understand and agree that it is a
>> stellar RDBMS.  I do not, however, use it for Gnucash.  The primary reason,
>> is as mentioned in item 1.  There are unresolved data integrity issues.
>> The secondary reason is that at this time, Gnucash has not been modified to
>> take advantage of any database functionality.  To your example, a partial
>> transaction could not happen in Gnucash, but for a different reason..  A
>> transaction between accounts in Gnucash does not involve a transaction
>> between 2 tables in Postgres.  This is because the data is essentially
>> stored in a flat file in Postgres.  It is loaded completely into memory and
>> all operations are done in memory with the results written back to the
>> database.
>> So, yes, while in theory, the RDBMS functionality of Postgres should
>> provide far superior data protection than the .xml file, in practice, it is
>> no better.
>> 
> 
> Sorry, I hope my explanation wasn't too tedious.
> 
> So gnucash doesn't update the PostGres DB using transaction semantics?
> That's interesting - not doubting you, that just seems odd.

It's true. GnuCash uses transaction semantics internally for updating its in-memory objects but does not use SQL transaction semantics when writing to the database. Changing that is high on the list of things to do after the backends are rewritten in C++.

Regards,
John Ralls