Merge stage mapping error
Posted: Mon Jun 09, 2008 3:04 am
I made a mapping error in a Merge stage, but the consequences of the error are inexplicable.
The first input file had columns, lets call them A, B, and C, that are all Decimal 7, Scale 1, Display 9. The output had identical columns, and I should have mapped A->A, B->B and C->C, but I accidentally mapped C->A, B->B, C->C. The actual column names were easily confused, and I was careless in not mapping them correctly.
The consequences of this, however, were that the C column contained entirely null values after the first record of output. I fixed the mapping by mapping A->A and re-ran, and this fixed the contents of the C column in the output.
Any idea what was going on here?
The first input file had columns, lets call them A, B, and C, that are all Decimal 7, Scale 1, Display 9. The output had identical columns, and I should have mapped A->A, B->B and C->C, but I accidentally mapped C->A, B->B, C->C. The actual column names were easily confused, and I was careless in not mapping them correctly.
The consequences of this, however, were that the C column contained entirely null values after the first record of output. I fixed the mapping by mapping A->A and re-ran, and this fixed the contents of the C column in the output.
Any idea what was going on here?