Target's PI and target type. How do you troubleshoot a source-to-target mismatch issue?

A source-to-target mismatch typically arises when the data being extracted does not align with the schema or constraints of the target system. To troubleshoot, first verify the source schema: check column names, data types, and cardinality. Next, examine the target schema for expected types, nullability, and constraints such as primary keys or foreign keys. Map each source field to its target counterpart and confirm that data type conversions are valid (e.g., converting a VARCHAR to an INT). Inspect the ETL logs or transformation scripts for any errors or warnings. If the tool supports data profiling, run a sample extract to see the actual values and compare them against the target expectations. Look for issues like truncation, overflow, or mismatched formats (date formats, currency symbols). If the mismatch is due to business logic, adjust the transformation rules or add validation steps. Finally, test the corrected mapping with a small batch before a full load. Throughout, maintain a clear mapping document and use version control for scripts to track changes.