At 03:17 PM 5/02/2009, you wrote:

>Hi All,
>
>I'd encountered this error while opening the FDB file sent by client
>using FB 1.0/1.5/2.0/2.1;
>
>Statement failed, SQLCODE = -820
>
>unsupported on-disk structure for file C:\SK.FDB; found 523, support XX
>
>So I think this ODS ver is not supported by any available firebird
>release.
>
>Can anyone suggest that ODS version 523 is belongs to which alpha/beta
>release?

That number doesn't tell you anything. If it is a Firebird database at all, it's probably one made with the Fb 2.5 alpha.

Or it might be an InterBase 6.5 or higher one (not compatible with Firebird).

Use gstat -h and see whether you can read the header page. If it works, you can see what its ODS version is.

./hb