Change Schema or Drop Temporal Table - Exam DP-203: Data Engineering on Microsoft Azure

Change Schema or Drop Temporal Table

Question

You need to change the schema for the temporal table you created earlier.

The below is the command that is used to change the schema or drop the temporal table.

Fill in the blanks with suitable words or values in the command.

…………

TABLE dbo.CustTemporal SET(SYSTEM_VERSIONING = …………)

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D. E. F.

Correct Answer: D

To drop the temporal table or change the Schema, first, you must set System Versioning to OFF.

The below is an example of the command:

Option A is incorrect.

ALTER, not MODIFY, is used to change the schema.

Also, System Versioning needs to be set to OFF.Option B is incorrect.

ALTER, not MODIFY, is used to change the schema.

Option C is incorrect.

ALTER, not MODIFY, is used to change the schema.

Also, System Versioning needs to be set to OFF.Option D is correct.

ALTER and OFF are the right solution.

Option E is incorrect.

System versioning needs to be set to OFF, not ON.

Option F is incorrect.

System versioning needs to be set to OFF, not NULL.

To know more about Temporal Tables, please visit the below-given link:

The given command is used to change the schema or drop the temporal table in SQL Server. The command specifies the table name and the action to be performed on the table.

The table in question is named "CustTemporal" and it has been created with temporal functionality using the "SYSTEM_VERSIONING" keyword, which means that a history table has been created automatically to track changes to the main table.

To change the schema of the temporal table, we can use the "ALTER" keyword followed by the "TABLE" keyword, the table name "dbo.CustTemporal", and the keyword "SET" to specify the new schema options.

The options for the "SET" keyword can be used to modify the temporal table settings. Specifically, the "SYSTEM_VERSIONING" option can be set to "ON" or "OFF" to enable or disable temporal functionality for the table.

Therefore, the correct answer is option E, which is "ALTER, ON", as we want to change the schema and set the "SYSTEM_VERSIONING" option to "ON" to maintain temporal functionality for the table.

Option A, which is "MODIFY, ON", is incorrect because "MODIFY" is not a valid keyword to change the schema of a table in SQL Server.

Option B, which is "MODIFY, OFF", is incorrect because it does not specify the correct keyword to change the schema, and it sets the "SYSTEM_VERSIONING" option to "OFF", which disables temporal functionality for the table.

Option C, which is "MODIFY, NULL", is incorrect because it does not specify the correct keyword to change the schema, and it sets the "SYSTEM_VERSIONING" option to "NULL", which is not a valid option for this command.

Option D, which is "ALTER, OFF", is incorrect because it sets the "SYSTEM_VERSIONING" option to "OFF", which disables temporal functionality for the table, whereas we want to maintain this functionality.

Option F, which is "ALTER, NULL", is incorrect because "NULL" is not a valid option to modify the "SYSTEM_VERSIONING" option.