DRAFT ETL+ Load Replace Example 2 - Primary Key Prevents Duplicates?
Examples of source data and the target tables that result from a Load Replace.
Key point: The so called DW PK column in the Design page does not put a PK in the target table!
Example Configurations
Column named key is designed as the DW PK.
Load Replace requires that at least one column be designated as a DW PK on the Design page.
Initial Load
Source file
Target Table After
ETL+ Preview Table
new Target Table
SSMS
Log: (4 rows loaded)
2nd Load Replace
Source file
Target Table Before Load
Target Table After Load
Row2 updated, ModifiedSequence = 105
key is designated the Primary Key (DW PK)
Two rows with the same DW PK!
Log: (2 rows replaced)
The result above – 2 rows with the same PK – would not be allowed if the ETL+ created the target table with the PK as designated on the Design page.
Design page for the Target Table shown above.