Question { Mphasis, 21320 }

why Datapump is faster than traditional export and import

Answer

The Data Pump is a server based utility vs. the traditional
Export / Import which are client based utilities. The
Oracle Data Pump is not compatible with the Export / Import
functionality.

The Oracle Data Pump can also use NETWORK_LINK
functionality to move data and metadata from a remote
database without a dumpfile using the network technology
between the two databases.

Question { Mphasis, 5155 }

orra 1555 what is this error,why it is occur?

Answer

The "ORA-01555 snapshot too old" error, which causes user
transactions to fail, is a nightmare for Oracle DBAs and
developers. It usually occurs after queries or batch
processes have been running for a long time, which means
you can lose many hours of processing when the error crops
up.