> Would you consider removing the default log4j properties file from
> the firebirdsql.jar?

I would consider to set
org.firebirdsql.logging.Logger.loggingAvailable to false. This would
require driver to be recompiled. But except few places in the code we
have checks if (Logger.isXXXEnabled()) Logger.XXX(...). If you set
that variable to false, you should driver should work faster because
no java.lang.String objects are created to be passed to Logget.XXX
method.

Best regards,
Roman Rokytskyy