Database Sequences
Database sequences are database objects that generate a series of unique, sequential integer values, typically used for creating primary keys or other unique identifiers in tables. They provide a reliable and efficient way to produce non-repeating numbers across multiple database sessions or transactions, ensuring data integrity and avoiding conflicts. Sequences are commonly supported in relational databases like PostgreSQL, Oracle, and SQL Server, where they automate the assignment of IDs without requiring manual intervention.
Developers should use database sequences when they need to generate unique identifiers for records in a table, such as primary keys, to guarantee uniqueness and avoid duplication in multi-user environments. They are particularly useful in high-concurrency applications where multiple transactions might insert data simultaneously, as sequences handle the generation atomically to prevent race conditions. Learning sequences is essential for database design in systems requiring scalable and consistent ID generation, such as e-commerce platforms or financial systems.