Parallel Sessions on Datapump Export (10.2.0.4)

Question

Hi,
We are using Oracle 10.2.0.4 on Solaris and I'm exporting a table using Datapump export.
The export includes a query which selects from three tables based on relevant conditions. The parfile specifies 'parallel=4' and the dumpfile setting uses %U so that it creates an appropriate number of files.
When I run the export using my own (DBA) account (i.e. expdp mr_dba parfile=exp_xyz.par) the export completes in 15 minutes and creates four dumpfiles. When I run the export as the schema owner using the exact same parfile (i.e. expdp schema_own parfile=exp_xyz.par) the export takes over two hours and only creates two dumpfiles.
Could anyone suggest things that I could look at to find out why there is such a difference in the elapsed time? The exports have been run a number of times as both users with the box having similar loads and the results are fairly consistent i.e. 15 mins for my user and two hours for the schema owner.
The schema owner does have a different profile and a different Resource Consumer Group but both my profile and the schema owners profile have 'sessions_per_user' set to Unlimited. In Resource Manager the Parallel_Degree_Limit_P1 value is set to 16 for my consumer group and is not set at all for the schema owners consumer group.
I have observed that when exporting under the schema owner the DBA_DATAPUMP_SESSIONS showed a DBMS_DATAPUMP session, a MASTER session and two WORKER sessions. When I run it under my user id it shows these four sessions but also shows three EXTERNAL TABLE sessions. This suggests that it is using a different approach but I'm not sure what would cause this.
Any advice would be very welcome. I haven't posted any specific information about the parameter file or the tables as I'm not sure what info people might require - so if you need specific details of anything please let me know.
Many thanks.

Answer 1

Sorry for the delay in responding - it took a couple of days for our security people to give me the go-ahead to make the changes (red tape is ridiculous here!)
The tweak to the consumer groups in Resource Manager didn't seem to make much difference and it continued to use the same plan (but it was worth trying it). I then granted the EXP_FULL_DATABASE role and it did indeed result in much better performance (and it created the four dumpfiles instead of two).
I'm still not sure why it makes such a difference - the export is only exporting a table from the users schema but it does query a table in someone else's schema to identify appropriate candidates. You would assume that providing it can access all the necessary information it would run at the optimum speed but obviously the EXP_FULL_DATABASE role makes a considerable difference.
Thanks again for both replies, much appreciated. Well done Dean for identifying the solution - great call.
Edited by: user2480656 on 21-Aug-2012 08:35