Multiple File Access

[Jerry Gitomer]

Adonis Vargas wrote:
> 
> i am writing a small database application, utilizing bsddb, and have come
> across
> a problem, when i have more than one thread accessing the database, thread1
> might be performing an output operation, then sync, but prior to the
> synching
> thread2 accessed the table and proceses the file in an out of sync format,
> then
> when thread2 syncs it reverts whatever thread1 did etc.
> 
> how do i go about this? ive thought up of a few scenarios to fix it but have
> come
> full circle.
> 
> any sugguestions would greatly be appreicated.
> 
> Adonis

Your best bet would be to switch to an RDBMS that was designed
as a multiuser
On Line Transaction Processing (OLTP) data base.  PostgreSQL and
MySQL are the two
most frequently mentioned RDBMS for use with Python (or just
about anything else).
Either can do the job.  I believe that the licensing provisions
are more liberal
for PostgreSQL (no license fees even when used in commercial
applications) but 
many consider it overkill for small applications.  

But, if data integrity is important to you the smartest thing to
do is bite the
bullet and go with PostgreSQL because, when it comes to
multi-user OLTP, PostgreSQL 
has been more widely used and probably has fewer undiscovered
bugs.  (Please note
that I am an Oracle DBA and based on my professional experience
and bias before
anything else an RDBMS must preserve the integrity of the data,
for if it does not
it is not worth having.)