Thanks for your answers.

> Describe what you want to achieve in real life and someone will advise

> you about the best model for your requirements.

Thanks that would be great.

I have a Delphi application which ships with  firebird embedded and a service.

The service fills the db with the data and the Application is the GUI where the user can configure and use the service to fill the db or to receive data from the db in order to display it in the GUI .

The installer installs the service and also places the firebird embedded files in a subfolder of the installation directory.

Both, the service and multiple instances of my application should be able to connect to the same database at the same time.

The server is set to SuperClassic ( I also tried the 'Classic' mode).

Both, the service and the application are installed locally on the same pc.

After the installation and the configuration of a database I am able to connect to the db with the service.

I am also able to simultaneously connect to the same db(while the service is also connected) if I run my Application.exe via 'Run as Administrator' (I can connect to the same db with multiple instances of my application

as long as all of the instances are started via 'Run as Administrator'). Everything works fine, but as soon as I open an instance of my application in non-elevated mode, I receive the message

"[ODBC Firebird Driver]Database is probably already opened by another engine instance on another Windows session."

I have also stopped the service and closed all instances. Then I opened my Application in 'normal' non-elevated mode and I am able to connect to the db.

Similar to the describe behaviour above I am now able to connect with multiple non-elevated instances to the db as long as non of them are started ia 'Run as administrator'.

It is not a question of "elevated" vs "non-elevated" users. Embedded
is *by design* a single-user model. A successful embedded connection
locks out all other users from connecting to the same database - hence
the error message you see. The *same user* can make multiple
connections from within the same application space.
So you mean that if I start one instance of my application normally and one instance of my application via 'Run as administrator' firebird

treats them as different users?

Arno

Von: firebird-support@yahoogroups.com [mailto:firebird-support@yahoogroups.com]
Gesendet: Donnerstag, 27. Oktober 2016 22:33
An: firebird-support@yahoogroups.com
Betreff: Re: [firebird-support] [EDatabaseError] How to simultaneously connect to a firebird database in elevated and non-elevated mode.

Embedded access to any database will only allow one connection.

Neville