Data Assignment and Update Methods for File Parameters

For File type parameters, the Data Assignment method that you select, together with your choice of Update method, affect the values that the Vusers use to substitute parameters during the scenario run.

The Data Assignment method is determined by the Select next row field, and the Update method is determined by the Update value on field.

The following table summarizes the values that Vusers use depending on which Data Assignment and Update properties you selected. It also includes an example of each for a table/file that has the following values: Kim; David; Michael; Jane; Ron; Alice; Ken; Julie; Fred

Update Method	Data Assignment Method
Sequential	Random	Unique
Each iteration	The Vuser takes the next value from the data table for each iteration. Example: All the Vusers use Kim in the first iteration, David in the second iteration, Michael in the third iteration, and so on.	The Vuser takes a new random value from the data table for each iteration. Example: The Vusers use random values from the table for each iteration.	The Vuser takes a value from the next unique position in the data table for each iteration. Example: For a test run of 3 iterations, the first Vuser takes Kim in the first iteration, David in the second, and Michael in the third. The second Vuser takes Jane, Ron, and Alice. The third Vuser, Ken, Julie, and Fred.
Each occurrence (Data Files only)	The Vuser takes the next value from the data table for each occurrence of the parameter, even if it is within the same iteration. Example: All the Vusers use Kim in the first occurrence, David in the second occurrence, Michael in the third occurrence, and so on.	The Vuser takes a new random value from the data table for each occurrence of the parameter, even if it is within the same iteration. Example: The Vusers use random values for each occurrence of the parameter.	The Vuser takes a new unique value from the data table for each occurrence of the parameter, even if it is within the same iteration. Example: The Vuser uses a unique value from the list for each occurrence of the parameter.
Once	The value assigned in the first iteration is used for all subsequent iterations for each Vuser. Example: All Vusers take Kim for all iterations.	The random value assigned in the first iteration is used for all iterations of that Vuser. Example: All Vusers take the first randomly assigned value for all the iterations.	The unique value assigned in the first iteration is used for all subsequent iterations of the Vuser. Example: The first Vuser takes Kim for all iterations, the second Vuser takes David for all iterations, and so on.

Update Method

Data Assignment Method

Sequential

Random

Unique

Each iteration

The Vuser takes the next value from the data table for each iteration.

Example: All the Vusers use Kim in the first iteration, David in the second iteration, Michael in the third iteration, and so on.

The Vuser takes a new random value from the data table for each iteration.

Example: The Vusers use random values from the table for each iteration.

The Vuser takes a value from the next unique position in the data table for each iteration.

Example: For a test run of 3 iterations, the first Vuser takes Kim in the first iteration, David in the second, and Michael in the third. The second Vuser takes Jane, Ron, and Alice. The third Vuser, Ken, Julie, and Fred.

Each occurrence

(Data Files only)

The Vuser takes the next value from the data table for each occurrence of the parameter, even if it is within the same iteration.

Example: All the Vusers use Kim in the first occurrence, David in the second occurrence, Michael in the third occurrence, and so on.

The Vuser takes a new random value from the data table for each occurrence of the parameter, even if it is within the same iteration.

Example: The Vusers use random values for each occurrence of the parameter.

The Vuser takes a new unique value from the data table for each occurrence of the parameter, even if it is within the same iteration.

Example: The Vuser uses a unique value from the list for each occurrence of the parameter.

Once

The value assigned in the first iteration is used for all subsequent iterations for each Vuser.

Example: All Vusers take Kim for all iterations.

The random value assigned in the first iteration is used for all iterations of that Vuser.

Example: All Vusers take the first randomly assigned value for all the iterations.

The unique value assigned in the first iteration is used for all subsequent iterations of the Vuser.

Example: The first Vuser takes Kim for all iterations, the second Vuser takes David for all iterations, and so on.

Note: If you select the Sequential method and there are not enough values in the data table, VuGen returns to the first value in the table, continuing in a loop until the end of the test.