- Datapump introduced in Oracle 10g whereas conventional exp/imp was used for logical backups in prior versions of oracle 10g. Exp/imp works even in all versions of Oracle.
- Conventional exp/imp can utilize the client machine resource for taking the backups but, the datapump works only in server.
- XML schema, XML types are supported in expdp/impdp but not in exp/imp
- Parallel execution is possible in datapump which is not supported in conventional exp/imp. Using the parallel option the datapump generates multiple dump files simultaneously.
- Datapump cannot export the data into sequential medias like tapes.
- Datapump has better control than exp/imp on the backup job with START, STOP and RESTART options.
- Datapump gives 15 – 50% performance improvement than exp/imp.
- Table Extent compression can be done using COMPRESS option whereas in datapump COMPRESSION does the dumpfile compression.
- Additional Features Available with datapump are:
a. Job Estimation can be done in datapump
b. SAMPLE parameter is used for taking the sample % data.
c. Failed export/import Jobs can be restarted
d. EXCLUDE/INCLUDE parameter allows the fine-grained object selection. Read More On EXCLUDE/INCLUDE...
e. Data remapping can be done using REMAPDATA parameter.
f. Export and import can be taken over the network using database links even without generating the dump file using NETWORK_LINK parameter.
g. CONTENT parameter gives the freedom for what to export with options METADATA ONLY, DATA, BOTH.
h. You don’t need to specify the BUFFER size in datapump
i. Job estimated completion time can be monitored from v$session_longops view.
j. Dump file can be compressed with COMPRESSION parameter. In conventional exp/imp you have to compress the dumps using OS utilities.
k. Data encryption can be done in datapump.
l. DATAPUMP has interactive options like ADD_FILE, START_JOB, KILL_JOB, STOP_JOB.
m. REUSE_DUMPFILES parameter asks the confirmation/rewrite the existing dumpfile.
- Few parameter name changes in datapump and it always makes confusion with parameters in normal exp/imp
IMP: fromuser, touser
- There are many more to explain about each parameter. Please raise your question in comment column. I will try to give you the explanation. J