Performance with ATTACH/DETACH with rowid
An index is created for rowids but, is not fragmented.
Resolving the problem
An ATTACH/DETACH will cause an index rebuild
Without rowids, performance of ATTACH/DETACH is faster.
Normally DETACH command will force table to keep only data. Indexes and constraints are not inherited. But, with rowids an "index" is created that is not a fragmented index, so it will need to be rebuilt.
This action will impact the overall performance of a DETACH.
The reverse will happen with an ATTACH command.