Oracle Sequences: Unique Primary Key Generation

In Oracle databases, a Sequence is a type of database object used to generate unique numerical values. It is commonly used to create unique identifiers for primary key fields in tables, as well as in other scenarios requiring unique numerical values.

“The main function of Sequence is as follows:”

1. Generate unique primary key values: Sequences can be used to generate unique numerical values for the primary key field of a table, ensuring that each record in the table has a unique identifier.
2. Ensure data consistency: Since the values generated by Sequence are unique and monotonically increasing, it can guarantee data consistency. In a concurrent environment, multiple transactions can independently generate Sequence values, avoiding issues of primary key conflicts.
3. Sequence can be used in other scenarios that require unique numerical values, such as generating order numbers or transaction IDs, in addition to generating primary key values for tables.
4. Efficiently generate unique values: Sequence generates unique values at the database level, unaffected by the application program. It can efficiently generate large amounts of consecutive unique values without the need to frequently interact with the database.

In conclusion, Sequence in Oracle generates unique numerical values and can be used for generating primary keys and other scenarios requiring unique numerical values to ensure data consistency and uniqueness.