impdp 在使用了dblink的时候，加了parallel，导人员数据的时候并行没有没有生效，除了存在大字段，还有什么会限制并行。
TABLE_EXISTS_ACTION TRUNCATE
State: EXECUTING
Bytes Processed: 0
Current Parallelism: 2
Job Error Count: 0

Worker 1 Status:
Process Name: DW02
State: EXECUTING
Object Schema: UCR_CI3
Object Name: TF_USER
Object Type: TABLE_EXPORT/TABLE/TABLE_DATA
Completed Objects: 6
Total Objects: 100
Worker Parallelism: 1

Worker 2 Status:
Process Name: DW04
State: WORK WAITING

NAME TYPE VALUE

db_writer_processes integer 4
SQL> show parameter job

NAME TYPE VALUE

job_queue_processes integer 1000