SQL - simultaneous GC access ?

[Mike or Penny Novack]

Databases allowing multiple simultaneous users (how that works).

Besides the database itself, there would be a DBM (database manager). 
Instead of applications directly reading or writing to the database, 
they would go through the DBM for access. You could think of the DBM as 
a "server". The DBM ensures that although multiple users could be 
reading the database at the same time, only one writing to it at any 
instant.

The database would only be accessible (in multi-user mode) while the DBM 
program was running.

Leave aside the question of whether there is an open source DBM 
available for the form of SQL gnucash is using << I come from the large 
system mainframe world; know what was used there, but not what exists 
for "little" computers >> Very few of us are working in an environment 
that would support this model. Yes, the 'nix users COULD do it. One 
machine, always up, the database and DBM running here, with users 
logging into this machine remote. But very few even of the 'nix users 
operate this way. We tend to use our machines as "personal" machines, 
not simply a terminal emulator for a session running virtual on another 
(always running) machine.

In other words, NOT just the data (the database) which has to be in some 
shared space, but a PROGRAM running there which controls access to the 
data.

Remember, things have to work when something goes wrong. When you are 
the sole user, you can know if a lock left behind was because the 
application locked up or your computer crashed. In a multi-user 
environment that is not so.

Michael D Novack