DS error while running the DS job

[sharma]

I am getting below mentioned error while running the DS sequence that runs several jobs:

main_program: Fatal Error: There are irreconcilable constraints on the number of
partitions of an operator: parallel APT_DBExportOperator in ORDER_NW_roe.
The number of partitions is already constrained to 4,
but an eSame partitioned input virtual dataset produced by
parallel Copy_nw has 1.
This step has 4 datasets:
ds0: {/export/home/gopalanp/QA/fw/Loader/Datastore//work/NW.ds
[pp] eSame->eCollectAny
op0[1p] (parallel NW)}
ds1: {op0[1p] (parallel NW)
[pp] eSame->eCollectAny
op1[1p] (parallel Copy_nw)}
ds2: {op1[1p] (parallel Copy_nw)
[pp] eSame<>eCollectAny
op2[4p] (parallel APT_DBExportOperator in ORDER_NW_roe)}
ds3: {op2[4p] (parallel APT_DBExportOperator in ORDER_NW_roe)
eAny>eCollectAny
op3[] (parallel APT_NZWriteSubOperator in ORDER_NW_roe)}
It has 4 operators:
op0[1p] {(parallel NW)
}
op1[1p] {(parallel Copy_nw)
}
op2[4p] {(parallel APT_DBExportOperator in ORDER_NW_roe)
}
op3[] {(parallel APT_NZWriteSubOperator in ORDER_NW_roe)
}

Can anybody explain me what exactly is this error?

[attu]

do an exact search on There are irreconcilable constraints on the number of [/b]