How datapool options affect values that a virtual user retrieves

The Open, Access, and Wrap modes that you select for a datapool affect the values that a virtual user retrieves. The Wrap mode also affects segmented datapools.

The following table lists the most common types of datapools and the options that you select to create them.

Datapool purpose Open mode selection Access mode selection Wrap mode selection
The datapool provides unique data values with in random order for every attempted transaction. The datapool is reset between test runs so that data can be reused. Segmented Shuffled Fetch only once per user
The datapool provides unique data values in any order for every attempted transaction. You determine which values are used so the values can be deleted and not reused in later test runs. Segmented Sequential Fetch only once per user
The datapool enables each virtual user get and keep a single unique data value throughout the virtual user's tests Segmented Sequential Fetch only once per user
The datapool provides randomly chosen nonunique data values to all users. Shared Random Wrap when the last row is reached
The datapool cycles through all data values without any concern for value reuse. Segmented Sequential Wrap when the last row is reached

How rows are assigned in segmented datapools

If a datapool is segmented, a fixed number of rows is assigned to each location. This number is completely independent of the number of users that run the test that contains the datapool. Instead, the number of rows assigned to a location is proportional to the number of virtual users assigned to that location. For example, assume that a schedule contains 25 virtual users, and 5 users are assigned to run at a specific location. This means that 20 percent of the data runs from each segmented datapool are the assigned rows for this location. All values are taken from that segment, or “slice,” of the datapool. Once those row values are exhausted, the datapool either wraps back to the first row of its assigned segment or, if no wrap mode is set, gives a null value.
Feedback