SQL Server 2016 introduced System-versioned Temporal Table to keep a history of data change by adding additional history table.

In the below article, You can read more about System-versioned Temporal Table and you must know all the rules before creating a System-versioned Temporal Table.

You can also enable System-versioned Temporal Table in the existing table.

Check this demonstration:

Create a table with sample data:

CREATE TABLE tbl_Employees
(
	EmpID INT PRIMARY KEY
	,EmpName VARCHAR(20)
	,EmpDepartment VARCHAR(20)
	,EmpSalary INT
)
GO
 
INSERT INTO tbl_Employees
VALUES 
(1,'Anvesh','Database',90000)
,(2,'Jenny','JAVA',65000)
,(3,'Martin','PHP',85000)
,(4,'Roy','PHP',94000)
GO

Enable System-versioned Temporal Table on this table:

ALTER TABLE tbl_Employees
SET (SYSTEM_VERSIONING = ON (HISTORY_TABLE=dbo.tbl_EmployeesHistory))
GO

You will get a below error because you must configure SYSTEM_TIME column.

Msg 13510, Level 16, State 1, Line 1
Cannot set SYSTEM_VERSIONING to ON when SYSTEM_TIME period is not defined.

Configure SYSTEM_TIME column:

ALTER TABLE tbl_Employees
ADD 
	StartTime DATETIME2 GENERATED ALWAYS AS ROW START DEFAULT GETUTCDATE()
	,EndTime DATETIME2 GENERATED ALWAYS AS ROW END DEFAULT CONVERT(DATETIME2, '9999-12-31 23:59:59.9999999') 
	,PERIOD FOR SYSTEM_TIME (StartTime, EndTime)  
GO

Now, enable System-versioned Temporal Table:

ALTER TABLE tbl_Employees
SET (SYSTEM_VERSIONING = ON (HISTORY_TABLE=dbo.tbl_EmployeesHistory))
GO

SQL Server 2016 introduced a new type of user table that is called System-versioned Temporal Table to keep a full history of data changes.

This is a very good addition to the SQL Server 2016 because to track data change history is always an important task for a big transactional system.

SQL Server already provides few features to track data change like Change Data Capture (CDC), SQL Server Auditing, can create a manual DDL Trigger.

Now, SQL Server 2016 System-versioned temporal table which is something good and very easy to implement on a specific table.
You can audit all data changes and can perform require analysis on it. In Case of invalid delete or update, you can recover your data.

Rules and Requirements:

• Can create your table using SYSTEM_VERSIONING=ON
• Define your history table name HISTORY_TABLE = TableName, which tracks data change history. (It creates automatically).
• Must define two additional columns [ValidFrom] and [ValidTo] with default ROW START and ROW END and must refer to as SYSTEM_TIME period columns.
• Must have a Primary key column.
• Same number of column and structure between both the tables.

Full demonstration:

Create a sampel System Version Table:

CREATE TABLE tbl_Students
(
	StudID INT PRIMARY KEY
	,StudName VARCHAR(50)
	,StudClass CHAR(1)
	,ValidFrom DATETIME2 (2) GENERATED ALWAYS AS ROW START  
	,ValidTo DATETIME2 (2) GENERATED ALWAYS AS ROW END  
	,PERIOD FOR SYSTEM_TIME (ValidFrom, ValidTo)  
) WITH (SYSTEM_VERSIONING = ON (HISTORY_TABLE = dbo.tbl_StudentsHistory));  
GO

Insert few sample records:

INSERT INTO tbl_Students 
(StudID,StudName,StudClass)
VALUES (1,'Roy','A'),(2,'Bony','B'),(3,'Mahi','C')
,(4,'Maria','A'),(5,'Ron','B'),(6,'Murey','C')
GO

Execute few DML statements:

UPDATE tbl_Students SET StudClass = 'B'
WHERE StudID = 4;
GO

DELETE FROM tbl_Students WHERE StudID = 2
GO

Check the result of both tables:

SELECT *FROM tbl_StudentsHistory

StudID  StudName      StudClass ValidFrom                   ValidTo
------- ------------- --------- --------------------------- ---------------------------
4       Maria             A         2017-01-06 05:47:23.73      2017-01-06 05:48:54.43
2       Bony              B         2017-01-06 05:47:23.73      2017-01-06 05:50:12.52


SELECT *FROM tbl_Students

StudID  StudName        StudClass ValidFrom                   ValidTo
------- --------------- --------- --------------------------- ---------------------------
1       Roy                 A         2017-01-06 05:47:23.73      9999-12-31 23:59:59.99
3       Mahi                C         2017-01-06 05:47:23.73      9999-12-31 23:59:59.99
4       Maria               B         2017-01-06 05:48:54.43      9999-12-31 23:59:59.99
5       Ron                 B         2017-01-06 05:47:23.73      9999-12-31 23:59:59.99
6       Murey               C         2017-01-06 05:47:23.73      9999-12-31 23:59:59.99