What is a sequence in oracle?
A sequence is a column in a table that allows a faster retrieval of data from the table because this column contains data which uniquely identifies a row. It is the fastest way to fetch data through a select query. This column has constraints to achieve this ability. The constraints are put on this column so that the value corresponding to this column for any row cannot be left blank and also that the value is unique and not duplicated with any other value in that column for any row.
What is a sequence in oracle?
A Sequence is a user created database object. A sequence can be shared by multiple users to generate unique integers. This object is used to create a primary key value. The sequence is generated and incremented by internal Oracle routine. This can be time-saving object because it can reduce the amount of application code needed to write a sequence generating routine.
Oracle sequence generates a series of unique numbers for numeric column of a database's tables.
Syntax :Create sequence seq_name
Increment by n
Start with n
Maxvalue n | NoMaxvalue
Minvalue n | NoMinvalue
Cycle | NoCycle
Cache n | NoCache ;
