The problem that oracle11g empty table cannot be exported by exp

A new feature of oracle11g, when the number of data bars is 0, no segment is allocated, so it cannot be exported.
Solution:
1. Inserting a piece of data (or deleting it again) is a waste of time, and sometimes hundreds of tables will be exhausted.
2 Before creating the database, use the following code to adjust and rebuild the table, both of which are not good:

alter system set deferred_segment_creation=false;

Here's the ultimate method:
first query which tables are empty:

select table_name from user_tables where NUM_ROWS=0;

3 Next, we generate the modification statement through select, and then copy the sql content in the result window and execute it in the command:

select 'alter table '||table_name||' allocate extent;' from user_tables where num_rows=0;

ok Execute the above sql, and then exp it, that is the moment to witness the miracle.


                                         Change the password validity period from the default 180 days to "unlimited"
ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME UNLIMITED;