DRAG DROP
You plan to deploy a database to SQL Azure.
You must create two tables named Table 1 and Table 2 that will have the following specifications:
Table1 will contain a date column named Column1 that will contain a null value approximately 80 percent of
the time.
Table2 will contain a column named Column2 which is the product of two other columns in Table2.
Both Table1 and Table2 will contain over one million rows.
You need to recommend which options must be defined for the columns. The solution must minimize the time it
takes to retrieve data from the tables.
Which options should you recommend?
To answer, drag the appropriate options to the correct column in the answer area.
Select and Place:
Answer: 
Explanation:
* Sparse columns are ordinary columns that have an optimized storage for null values. Sparse columns reduce
the space requirements for null values at the cost of more overhead to retrieve nonnull values. Consider using
sparse columns when the space saved is at least 20 percent to 40 percent.* A Persisted column would be faster to retrieve.
* A computed column is computed from an expression that can use other columns in the same table. The
expression can be a noncomputed column name, constant, function, and any combination of these connected
by one or more operators.
Unless otherwise specified, computed columns are virtual columns that are not physically stored in the table.
Their values are recalculated every time they are referenced in a query. The Database Engine uses the
PERSISTED keyword in the CREATE TABLE and ALTER TABLE statements to physically store computed
columns in the table. Their values are updated when any columns that are part of their calculation change.
References: Use Sparse Columns
Specify Computed Columns in a Table