Subject Re: [IB-Architect] Database files > 2GB.
Author Bill Karwin
> From: "Jason Chapman" <jason@...>
> 1) It appears that I will have a _Major_ problem when
> the backup file breaches 2GB as Gsplit is not supposed
> to work under NT - what am I going to do?

I think gbak files don't suffer from the 2GB limit, because it has no need
to treat gbak files as random-access files. It treats them more like a tape
device. That is, a stream of data. Since NTFS seems to support files
larger than 2GB, I think you can create a huge gbak file and restore from it

It's worth a test to make sure, though. :)

> 2) ... The secondary file seems to not believe in relative
> addressing ...
> Whichever, it means that I must always have the GDB
> in the same location, i.e. e:\data\sqldata\DBName which
> has just made my database a whole lot less portable.

This is an often-cited "gotcha" with multi-file databases. The path to the
secondary files is written in the header page of the primary gdb file, and
there is currently no tool that can alter these paths. You might be able to
do it with a binary editor (make sure no one is attached to the database!).
But you might have to ensure that the paths have the same number of

It would be challenging to do so in the general case, because if there are
many files with long pathnames, the list can easily fill up the header page.
InterBase allocates more header pages as necessary to store all the
filenames. The extra header pages are not necessarily contiguous.

The system table RDB$FILES stores the paths of secondary files and shadow
files, but this is read-only; changing these values _doesn't_ change where
InterBase looks for the secondary files.

Ideally, there should be a tool to edit the header page(s), or perhaps
syntax for the ALTER DATABASE statement to change the location of secondary
files. This would have to work even if (especially if) the database could
not be readied due to mislocated secondary files.

This problem doesn't seem like it's unsolvable. It's a good candidate for a
contributed enhancement after IB 6.0 is released and the source is opened.
Whomever does it would be a hero!

Bill Karwin