Hi Helen,

> Just put this dummy query in a **read-only read committed**

transaction on

> its own and keep the transaction uncommitted. No need for a

timer. For

> tidiness, just remember to commit it as part of your disconnection

routine.

unfortunately it does not help, even an open transaction with "write
read committed" will be dropped. Sorry, that I didn't describe the
problem with more detail.
We think it is the linux firewall, that drops inactive tcp
connections after 30 min. I'm also not sure if the v1.03 had this
also or is it new to v1.5. The Firebird server probably just closes
the socket after the connection is dropped by firewall (nothing in
the server log), client computer has the 10054 messages in the log
file after each disconnect.

Ivan suggested to use isc_database_info(), I will try this next.

regards,
Harri