Using the HyperFileSQL logs, you can figure out which queries are used the most and which queries take a long time to run. These queries should be optimized.

To optimize a query, WinDev offers a query optimizer, accessible via the "Project .. Performances and enhancements .. Optimize the project queries" menu option.

The query optimizer lets you see in just a few click whether you need to add key items to the various data files in order to optimize the queries' execution.
Simply select the queries to check and click the "Run the performance analysis" button. WinDev displays the keys to add to the data files to optimize the queries then.
If the optimizer detected some missing keys, simply click the "Apply all modifications" button and WinDev will automatically create the needed keys.
Then, simply regenerate the analysis with the automatic data file modification option.

Note:
When a query is created, WinDev automatically performs this performance analysis. If an optimization is possible, an AAD (Aided Application Development) suggestion will be displayed in the query editor.