A sequence in SQL is a powerful feature used to generate a series of numeric values in a designated order.

To elaborate, a sequence in SQL functions as a database object that produces a list of integers. It is primarily utilized to automatically create unique identifiers for rows within a table, which is especially beneficial for assigning unique primary key values to new entries in a database.

Sequences are established using the ‘CREATE SEQUENCE’ statement, and the next value in the sequence can be retrieved with the ‘NEXT VALUE FOR’ function. Notably, the series of numbers generated by a sequence is unaffected by database rollbacks, and the sequence does not automatically reset when it reaches its maximum value.

The sequence object generates numbers based on specific parameters defined at the time of its creation. These parameters include the starting point, the increment value, the maximum and minimum values, and whether the sequence should cycle when it reaches its limit.

For instance, if you have a table containing student records and you need to assign each student a unique ID, a sequence can be employed. When a new student is added to the table, the sequence will automatically generate a new, unique ID for that student. This guarantees that each student is uniquely identifiable by their ID, which is particularly advantageous in large databases where manually assigning unique IDs would be impractical.

In conclusion, a sequence in SQL serves as an effective tool for automatically generating unique identifiers, thereby ensuring data integrity and streamlining database management.