Table validation is a process that verifies that the content of a specific table matches across the Teradata Systems. You can validate a table using row count, a validation expression, or both. You can set up table validation manually, with triggers, or as part of a workflow.
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. Custom or validation expressions are not supported for table validation that involve Hadoop or Aster systems. 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.
- Partial Table Validation
- The WHERE clause allows you to specify only part of a table. For example, to include only table information related to the month of October, add a statement Column x=Oct.
Before table validation, the metrics are automatically reset to zero. The results of table validation appear in the Table Metrics view in the Ecosystem Explorer portlet.