Oracle: Tables and Views missing from the all_objects dictionary

You have a few options, some of which will make your database unsupportable by Oracle (if you care!) as you need to fiddle with SYS owned objects.

The first option is to revoke select privs from everyone:

revoke select on all_users from public;

Then grant it back to certain users, plus all other internal Oracle users.

The 2nd option is to look at the source for the view, drop it, then recreate an altered version that supports your needs.

Another option that would trick casual users would be to create a table called ALL_USERS in each schema. Unless the logged in person explicitly qualified ALL_USERS (ie: SYS.ALL_USERS) they would get the resultset from the table in their own schema. This trick could also be done with a synonym pointing to a view that does:

select * from all_users where username = (SELECT sys_context('USERENV', 'SESSION_USER') from DUAL);

Not much else you can do with XE I'm afraid.

There is no such one command to do this kind of migration of a schema because as you mentioned, Oracle Express edition doesn't support all the features that are used in the Enterprise edition. However, I tried to collect some of the useful parameters which can be used during expdp/impdp to modify or include/exclude (un)wanted objects and features.

partition declarations can be omitted.

In that case you can use PARTITION_OPTIONS parameter in impdp.

PARTITION_OPTIONS=[NONE | DEPARTITION | MERGE].

PARTITION_OPTIONS

storage declarations omitted or simplified (e.g. as little as possible initial space reserved for tables).

TRANSFORM parameter in impdp enables you to alter object creation DDL for objects being imported.

TRANSFORM = transform_name:value[:object_type]

TRNASFORM

tablespace declarations omitted or replaced (a single tablespace used in XE).

You can use REMAP_TABLESPACE parameter during impdp on Oracle XE instance.

REMAP_TABLESPACE=source_tablespace:target_tablespace

REMAP_TABLESPACE

materialized views with some advanced features can be simplified or replaced with simple views.

I think you need to import DDL of such materialized views into a SQL FILE then create view manually.

jobs can be omitted.

You can use EXCLUDE parameter to exclude jobs but currently, Data Pump Export/Import can exclude/include jobs which were created with DBMS_JOB.

Reference

java functions (scarsely used but present in one pl/sql package) can be disabled or imported with compilation errors.

You can use EXCLUDE to ignore such java classes.

EXCLUDE=JAVA_CLASS

Now you can combine these parameters to form your expdp/impdp command.

Note: All included reference links are related to Oracle 11g version, please refer to the Oracle documentation related to your version.