Difference between Synonyms in oracle

The rules for name resolution are described in the documentation.

When you run your query against sys.dba_objects you are directly accessing the SYS-owned view called dba_objects. When you run your query against the unqualified dba_objects then you may access a table or view that you own, or an object you or someone else owns, through a private synonym (that you own) or a public synonym.

Usually there is just a public synonym for the dba_* views, which means that if you refer to dba_objects then you are still actually looking at sys.dba_objects, via that default public synonym.

In your case two users have private synonyms with the same name. If you are connected as either READ_ONLY or RM2_READ_ONLY then those users' private synonyms will be used; so when you reference dba_objects you will actually be looking at o2support.rm_dba_objects, which - based on the results you're getting - is completely unrelated to the current contents of sys.dba_objects.

To summarise: you have a private synonym which is taking precedence over the public one, and the two statements are querying different tables.

I'd guess it's an earlier snapshot of objects in the system, possibly - from the name - of objects that were going to be removed, perhaps as a reference for reinstating them if needed. Whatever it is, it's stale and you don't seem to want to be seeing its contents.

If you want to see the current data dictionary then you will have to continue to refer explicitly to sys.dba_objects, or see if the private synonyms can be safely removed.

(It's not very useful, but you can also explicitly refer to the public synonym; but the owner has to be supplied as a quoted identifier, i.e. "PUBLIC".dba_objects. There's no benefit in doing that over referring directly to sys.dba_objects though.)