How I can find a running Oracle database is started using PFILE or SPFILE?

You can check through following ways

Check in v$parameter view

Select * from v$parameter where  upper(name)  like ‘SPFILE’;                              

or

SHOW PARAMETER SPFILE. 

If you find any data in above query then it started using SPFILE else with PFILE.

What is Oracle Data Pump (impdp and expdp)?

• Oracle Data Pump is a new feature of Oracle Database 10 g that provides high speed, parallel, bulk data and metadata movement of Oracle database contents.
• DBMS_DATAPUMP package  provides a server-side infrastructure for fast data and metadata movement. expdp and impdp is used to import/export activites.
• It vastly improved performance and greatly enhanced functionality, such as restartability, flexible object selection, and better monitoring and control of export and import jobs.
• Data Pump is server-based, rather than client-based. Dump files, log files, and SQL files are accessed relative to server-based directory paths, so that appropriate file security can be enforced.
• Data Pump requires you to specify directory paths as directory objects. A directory object maps a name to a directory name on the file system.
• Before you can run Data Pump Export or Data Pump Import, a directory object must be created by a DBA or by any user with CREATE ANY DIRECTORY privilege.