Clarification on correct configuration for multiple Windows processes writing to the same embedded Firebird DB

[nir-moshe]

Hello,

I’m using Firebird 5.0.1 on Windows, and I’d like to run it in embedded mode.
My setup involves two separate Windows processes, and each process has multiple threads writing to the same database file.

I want to confirm the correct configuration for this use case.

Currently, my setup is as follows:

In firebird.conf:

ServerMode = SuperClassic

Connection string:

Charset=UNICODE_FSS;clientlibrary={Path_to_fbclient.dll};ServerType=1;Dialect=3;
User={user};Password={password};Database={dbpath};
Pooling=true;MinPoolSize=0;MaxPoolSize=100;Connection lifetime=15;

Questions:

1. Is this configuration correct for multiple Windows processes writing concurrently to the same embedded database file?

If not, what is the recommended setup (ServerMode, connection parameters, etc.) for this scenario?

2. Would using Classic be more appropriate for this use case?

Additional info (if relevant):

Windows version: Windows 11 Pro 64-bit

Firebird version: Firebird 5.0.1

Database file is stored on a local disk (not a network share).

Thank you for your help and for maintaining this great project!

[mrotteveel]

As far as I'm aware, in the case of embedded, the Classic and SuperClassic setting value will behave identical, as the connections are all in one and the same process.

[AlexPeshkoff]

On 10/23/25 10:44, Mark Rotteveel wrote: As far as I'm aware, in the case of embedded, the |Classic| and |SuperClassic| setting value will behave identical, as the connections are all in one and the same process.

Exactly

[hvlad]

Is this configuration correct for multiple Windows processes writing concurrently to the same embedded database file?

Yes.

Would using Classic be more appropriate for this use case?

It is the same.

Take into account that in case of your process crashes, database consistency could be at risk.
Also, don't use UNICODE_FSS, use UTF8 instead.