A sequence is a user-defined schema bound object that generates a sequence of numeric values according to the specification with which the sequence was created. The sequence of numeric values is generated in an ascending or descending order at a defined interval and can be configured to restart (cycle) when exhausted. Sequences, unlike identity columns, are not associated with specific tables. Applications refer to a sequence object to retrieve its next value. The relationship between sequences and tables is controlled by the application. User applications can reference a sequence object and coordinate the values across multiple rows and tables.
CREATE SEQUENCE [schema_name . ] sequence_name
[ AS [ built_in_integer_type | user-defined_integer_type ] ]
[ START WITH <constant> ]
[ INCREMENT BY <constant> ]
[ { MINVALUE [ <constant> ] } | { NO MINVALUE } ]
[ { MAXVALUE [ <constant> ] } | { NO MAXVALUE } ]
[ CYCLE | { NO CYCLE } ]
[ { CACHE [ <constant> ] } | { NO CACHE } ]
[ ; ]
1)Independent from table. Example : Example : CREATE SEQUENCE [dbo].[Sequence_ID] AS [int] START WITH 1 INCREMENT BY 1 MINVALUE 1 MAXVALUE 1000 NO CYCLE NO CACHE http://raresql.com/tag/sequence-vs-identity-in-sql-server-2012/ http://www.c-sharpcorner.com/UploadFile/ff2f08/identity-vs-sequence-object-in-sql-server/ http://msdn.microsoft.com/en-IN/library/ff878091.aspx
