How to instruct data pump import to load whatever it can from a corrupted source

Oracle 18c introduces a new option to the parameter DATA_OPTIONS: CONTINUE_LOAD_ON_FORMAT_ERROR.
This option will tell data pump import to skip forward to the start of the next granule if a stream format error is encountered while loading data.
In previous versions, if a format error was found, impdp would abort and already loaded rows would be rolled back.

If you find yourself in a situation where all recovery options have failed you, then you might save at least some of the source data using this parameter.

Used in a simple paramter file called impdp.par:

USERID=system
FULL=y 
DUMPFILE=mydumpfile.dmp 
DIRECTORY=DP
TABLE_EXISTS_ACTION=replace 
DATA_OPTIONS=CONTINUE_LOAD_ON_FORMAT_ERROR

Execute:

impdp parfile=impdp.par

The feature is documented in the 18c new features documentation.

See also the utilities documentation for 18c

How to create a private temporary table from Oracle 18c and onwards

The default is to throw away the data after a transaction ends with commit or rollback:

create private temporary table ora$ptt_mytemptab
on commit drop definition;

You could also let the data be visible for the entire duration of the session:

create private temporary table ora$ptt_mytemptab
on commit preserve definition;

The notation ora$ptt is derived from the parameter private_temp_table_prefix:

SQL>show parameter private_temp_table_prefix

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
private_temp_table_prefix            string      ORA$PTT_

It must be included in the create statement of the PTT. You can find information about your PTTs in the dictionary:

set lines 200
col table_name format a20
col tablespace_name format a20
col duration format a20
col num_rows format 99999999
SELECT sid, serial#, table_name, tablespace_name, duration, num_rows
FROM   user_private_temp_tables;

In my case the output is:

      SID    SERIAL# TABLE_NAME           TABLESPACE_NAME      DURATION              NUM_ROWS
---------- ---------- -------------------- -------------------- -------------------- ---------
       280      12720 ORA$PTT_MYTEMPTAB   TEMP                 SESSION                    107

The column "duration" will show whether it is preserving data for the session or the transaction.

Read more about PTTs in the Oracle 18c documentation

Oracle streams being terminated with Oracle 18c

As noted in the "Desupported features" section of the Oracle 18c documentation, Oracle Streams will be terminated in with the release of Oracle 18c.

For replication, Oracle Corporation encourage their customers to use GoldenGate.