1. If the table is partitioned, then there would be n DataPump Worker processes active (where n is the value of the parallel parameter), each unloading data from one of the table partitions.

2. Include a where clause in the EXPDP command to segment the export and run multiple EXPDP to simulate parallelism:

The expdp command has a QUERY parameter which enables you to filter the data that is exported by specifying a clause for a SQL SELECT statement.
The query_clause is typically a WHERE clause for fine-grained row selection, but could be any SQL clause
This QUERY parameter could be used to run different exports from the same table at the same time, exporting a range of rows in each operation.

1，查询一下等待事件
2，检查内存设置

1.如果没有必要可以不去导统计信息
2.加并行

lob导出确实很慢，不能用并行，感觉没辙