Hi,
If you built a static dictionary following
this, you may reprocess offline any databases with that dictionary with rtabmap-reprocess:
rtabmap-reprocess \
--Kp/DictionaryPath ~/dictionary.db \
--Kp/IncrementalDictionary false \
rtabmap.db output.db
Add "--Mem/UseOdomFeatures false" if you also want to re-extract features.
You can use rtabmap-info to show loop closures detected afterwards.
cheers,
Mathieu