Subject Re: [ib-support] Help please! Database corrupt!
Author Ann W. Harrison
At 02:05 AM 5/4/2001 +0700, Nello Sestini wrote:

> > You may well have a bad page in the database. I'd suggest
> > you backup the database with both garbage collection and
> > checksum checking turned off. If that works, restore the
> > database and things will be fine.
>Can you elaborate just a bit why this works?

Sure. The important part (I think) is turning off garbage
collection. What you've probably got is an uninitialized
page that's referenced from somewhere. If you're not using
forced writes, that can happen in a server crash. Gbak
reads only the committed records. If you tell it not to
garbage collect, it won't look at back versions and other
places likely to be broken. Nor does it look at indexes,
another potential source of problems.

A checksum error is an interesting problem since checksums
haven't been used since V4. However, the space that had been
held by the checksum is now filled with the number 12345.
Your page has something different, which is why I think it's

>Does backing up somehow "fix" the data error that caused
>the original checksum check to fail?

Backup/restore creates a new database and stored all the
old data in it. Structural problems don't survive the
transition - anything "page level" is totally replaced.


We have answers.