When you need to retrieve items from a list with lots of fields, and that you need to get the history (versions) for some specific field (typically, when you can add comments to an item by setting the “Append Changes to Existing Text” option to Yes), you may be facing performance issues. The reason is due to both the limitation of SharePoint Web Services and the fact that Enesys RS Data Extension will retrieve versions for all the fields you have selected.

In version 3.5, it will be possible to specify the specific fields for which you would like to retrieve version information. In the meantime, the following Knowledge Base Article describes a solution that involves using a sub-report. Depending on your specific scenario, the approach explained in the article may greatly improve the overall performance of your report.