Adam,

> I had a report from a customer about a corrupt database, and I am
> looking for any hints to determine what has actually occurred and
> (hopefully) what may have caused it.
>
> Win 2003 Server, 1.5.5 Classic, from firebird.log:
>
> SERVER Tue Oct 28 14:30:04 2008
> Database: E:\DATA\DATA.FDB
> database file appears corrupt ()
> wrong page type
> page 195537 is of wrong type (expected 7, found 5)
> internal gds software consistency check (error during savepoint
> backout (290))
>
> This error occurs hundreds of times as different connections have hit
> the corrupt page and crashed.

A backup/restore will correct the problem, but the solution(*) is to
move to a more recent version of Firebird. There was a bug in the
index re-combination code that could, under heavy load, leave a
pointer in a parent node to a page that had been a lower level index
node, but had since been recombined, released, and reused as a
data page.

(*)90% certainty.

Cheers,

Ann