Hello Seyeong,

Tuesday, June 21, 2016, 12:52:51 PM, you wrote:

> SQL>> connect "/home/user/a.fdb" user '*******' password '**********'; 

> Statement failed, SQLSTATE = HY000
> file /home/user/a.fdb is not a valid database

> Note that the example file, employee.fdb is accessible.

> Again, the same file is perfectly accessible on Windows with FlameRobin.

My top suspicion is that you have a backup file there that you have
inadvertently named with the ."fdb" extension. I suggest you try
again, this time just making certain about those file names when you
back up and restore.

BTW, this error has nothing to do with the file name: it is raised
when the engine finds the named file but can't find a database header
page in it.

Also, Firebird doesn't care about extensions at all. ".fdb" for
databases and ".fbk" for backup files are just a convention.

Helen