Data validation as part of a data warehouse migration from Teradata Vantage to Snowflake

Data reconciliation at the table level serves to systematically identify and quantify discrepancies between the two environments. Particular attention must be paid to database-specific characteristics, especially with regard to data types. A particular challenge is that both environments cannot be operated synchronously, which means that deviations are to be expected, especially in transaction tables. Together with the customer, PTA develops a schedule that defines a suitable strategy for the comparison depending on the size and type of tables (master or transaction tables). Since a large number of tables need to be checked, particular importance is also attached to the runtime of the comparisons during planning. Based on the results of the table comparison, PTA designs a Tableau dashboard to identify specific problem areas.