Understanding Surrogate Keys in Siebel

In Siebel, a surrogate key is an artificially generated unique identifier used as the primary key for a record in a database table. It serves as a substitute for natural keys, which are based on real-world, meaningful attributes. In Siebel, surrogate keys are typically used to maintain uniqueness and are system-generated to avoid relying on business data for primary key purposes.

Characteristics of Surrogate Keys in Siebel

• Uniqueness: Each record in a table has a unique surrogate key to ensure proper identification.
• System-Generated: In Siebel, the surrogate key is usually the ROW_ID field, which is automatically generated.
• Hidden from Users: Users do not see or interact with surrogate keys directly; they are used internally for record identification and relationships.
• Data Independence: Surrogate keys are not tied to business data, ensuring that changes in business attributes do not affect the relationships or keys.
• Fixed Length: ROW_ID is usually a fixed-length alphanumeric value in Siebel (15 characters by default).

Example in Siebel

Consider a "Contact" table that stores information about customers. Instead of using the customer's email or phone number as the primary key (which may change over time), Siebel generates a unique ROW_ID for each contact record.

ROW_ID	First Name	Last Name	Email
1-ABC123	John	Doe	john.doe@mail.com
1-DEF456	Jane	Smith	jane.smith@mail.com

Benefits of Using Surrogate Keys

• Stability: Business data can change, but surrogate keys remain constant, ensuring data integrity.
• Simplifies Relationships: Using surrogate keys helps avoid complexities when linking tables, especially in many-to-many or hierarchical relationships.
• Efficient Joins: Surrogate keys are compact and efficient for database indexing and query joins.

Common Interview Question on Surrogate Keys

Q: Why does Siebel use ROW_ID as a surrogate key instead of natural keys like email or phone numbers?

A: ROW_ID ensures that each record is uniquely identified regardless of changes to business data. Natural keys like email or phone numbers can change over time, potentially causing issues with data consistency and relationships. ROW_ID, being system-generated and immutable, ensures data stability and simplifies database operations.