For custom validation rules, write SQL statements that are well formed and well tuned. The SQL statement is executed as part of the WHERE condition for incoming data.
Custom validation rules decrease the performance of the load process. Use sparingly.
Use the SQL syntax that is required by your database platform. If you need more information about SQL WHERE clause syntax and wild card patterns, refer to the product documentation for the database platform that is used in your
Informatica MDM Hub
implementation.
Be sure to use parentheses to specify precedence. Incorrect or omitted parentheses can have unexpected results and long-running queries. For example, the following statement is ambiguous and leaves it up to the database server to determine precedence:
WHERE conditionA AND conditionB OR conditionC
The following statements use parentheses to explicitly specify precedence:
WHERE (conditionA AND conditionB) OR conditionC
WHERE conditionA AND (conditionB OR conditionC)
These two statements yield very different results when evaluating records.