db 4 GB bigger?! Rebuild db - what information might I lose?

The DTPro Office Manual says about the database rebuilding the following:

I have a database with many indexed documents and less (but also many) rtf and txt documents which were created partially from indexed pdfs and partially created “freshly”.
… and I have loads of tags (also nested hierarchically in groups) assigned to the documents.

… I dont exactly understand what the hint “you may lose some meta data…” means in reality…
Can anybody help?

My problem is (as described in many recent posts here):
I had hundreds of indexed documents which should reside in their original directory structure and should be replicated in other groups.
I don’t know exactly what I did wrong, but many of those documents suddenly had any replicants any more and did only exist in the new groups (and not in their original structure).

Example:
I had a folders “pdf_catalog” which I had indexed.
And in DTPro the indexed folder had only 5xxx documents, but in reality >6000, so there were some missing…
I indexed it again (Ctrl-Alt-dragged it to another tmp group in the DB) and removed the original indexed directory in the DB.
But now my DB has grown from 8,13 GB to 16,6 GB. :frowning:
(and the backups which I have created in the meantime during the process of changing and re-structuring the database are only about 4 GB big…).

So I wonder where the additional 4,x GB came from and how I can get rid of them.

So the question is, how can I get rid of this duplicate information and duplicate disk usage.

[edit:]

I checked the contents of the 2 database packages (from the backup and the new one) and the difference comes from a Files.noindex folder which grew from 1,2 to 7 GB!
I did a check for unique files with Tidy Up and there are many JPG and PDF files which are new in the new database.
I just picked one example (don’t know if it’s representative), but it is a pdf which is only indexed, but a copy of it exists in the database.
Is that normal?
Kind regards

Martin

… ok, after verify and repair, there were >5000 orphaned files which occupy about 5,8 GB disk space…

I’ll export them and then remove them from the database.