Table validation verifies that the content of a specific table matches across the Teradata Database systems. You can validate a table using row count, a validation expression, or both for some types of systems. You can set up table validation manually, with triggers, or as part of a workflow.
Ecosystem Manager includes an Expression Helper to assist you in creating a WHERE clause or a validation expression.
Ecosystem Manager does not perform explicit internal datatype cast operations for different database systems involved in table validation. The schema of tables to be validated must be the same across different database systems or if a WHERE clause is specified the datatype for the column must be the same across different database systems. For Hadoop or Aster systems, you may only use the Row Count and Partial Table Validation. For Hadoop systems, SQL-H related limitations and recommendations apply.
- Row Count
- The Row Count validation method accesses the master cylinder index. Row count indicates tables are synchronized with the same number of rows, but does not confirm the rows have the same values.
- Validation Expression
- The Validation expression allows you to create a custom expression to compare the sums of columns in tables. If the custom expression is not an aggregate, Ecosystem Manager will place the expression inside a function to make it aggregate. You can use the Expression Helper to insert actions and columns into an expression.
- Partial Table Validation
- The WHERE clause allows you to specify columns to use for table validation instead of the whole table. You can use the Expression Helper to see the available columns.
Before table validation, the metrics are automatically reset to zero. The results of table validation appear on the Tables tab in the Table Metrics view in the Ecosystem Explorer portlet.