At 10:08 AM 10/04/2008, you wrote:

>Hi everybody!
>
>I have a firebird database been used by 10 users simultaneously.
>I've made a routine to backup this database 3 times a day.
>The thing is: Can the backup routine (using gbak) crash the database
>if the users are connected?

No. Databases don't crash. The server can be made to crash under certain conditions - but never just from reading

>I think it can't but I've seen a site once saying that it could.

Ah, well, if it was on a website, it must be true! ;-)

>I don't know how gbak works but I guess it opens a snapshot
>transaction and read database structure and records saving it to the
>backup file. So, it would act as any other user connected to the
>database.

Exactly right. And the transaction is a read-only transaction. And it doesn't execute any UDFs or create garbage or mess up character sets, as human users and bad application code written by humans can sometimes do.

>Thinking that way, saying that gbak can crash a database
>with connected users would mean the same as saying that any user could
>crash the database, right?

Some users could crash the server, if they invoked a bad UDF. Databases don't "crash" since they are not executable programs.

>Am I wrong? Did anyone here have any experience to share?

Probably most of us. :-)