Difference between formDataSource.query() and formDataSource.queryRun().query()

Any form has 2 instances of the query object - one is the original datasource query (stored in formDataSource.query()), and the other is the currently used query with any user filters applied (stored informDataSource.queryRun().query()). 

When the research method is called, a new instance of the queryRun is created, using theformDataSource.queryRun().query() as the basis. Therefore, if the user has set up some filters on the displayed data, those will be preserved.

This is useful, for example, when multiple users work with a certain form, each user has his own filters set up for displaying only relevant data, and rows get inserted into the underlying table externally (for example, through AIF).
Calling executeQuery, on the other hand, will use the original query as the basis, therefore removing any user filters.