After creating a data set, always use Preview Results to verify that the data set returns the expected data. Figure 2‑4 shows an example of a result set returned by a JDBC data set. By default, Preview Results shows up to 500 data rows. If you expect the data set to return more than 500 data rows and you want to see all the rows, increase the number of rows that Preview Results displays. Doing so, however, can increase the amount of time it takes to display the results.