> Just in case there's confusion, Firebird does not create multiple

copies

> of blobs unless the blob itself changes. If other fields are modified,
> all the record versions will reference the same copy of the blob.
>

Thanks Ann, I should have mentioned that. In hindsight, I suppose a
lot of document management systems need to keep older versions anyway
and so will not delete the old document just because someone has
changed it.

Adam