ORA-30036: unable to extend segment by 8 in undo tablespace 'UNDOTBS1'

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#  Error
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ORA-30036: unable to extend segment by 8 in undo tablespace 'UNDOTBS1'

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#  Full Error 
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ORA-39171: Job is experiencing a resumable wait.
ORA-30036: unable to extend segment by 8 in undo tablespace 'UNDOTBS1'
ORA-39171: Job is experiencing a resumable wait.
ORA-30036: unable to extend segment by 8 in undo tablespace 'UNDOTBS1'

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#  Cause
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Error occurred while trying to import a schema using datapump of 11.2.0.1.0 version.

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#  Command Executed
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impdp -- Schema Import

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## Solution
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### 11.2.0.1.0

1) Index maintenance activity will be performed when impdp import is in progress, so disable the primary key constraints in the tables, then undo generation will be less and import will be successful.

2) In case if import is still failling after disabling primary constraints then try to add some more space to UNDO tablespace.

For me 1st solution worked.