I would add the clause LIMIT in the query which performs join to obtain only one row of the result set. For instance, If I have a join view called dv_join_view then I would execute the following query:
`Select * from dv_join_view LIMIT 1`
Similarly, I would use OFFSET and FETCH clauses to limit the number of rows obtained when executing a query.
Additionally, I could also limit the no. of rows graphically by following the steps given below:
* Open the derived view
* Click the Execution panel.
* Edit the Limit Rows/Display Rows value to the desired value.
For more information, you can have a look at the sections [OFFSET, FETCH and LIMIT](https://community.denodo.com/docs/html/browse/latest/vdp/vql/queries_select_statement/offset_fetch_and_limit/offset_fetch_and_limit#offset-fetch-and-limit) of the Virtual DataPort VQL Guide and [Querying Views](https://community.denodo.com/docs/html/browse/latest/vdp/administration/creating_derived_views/querying_views/querying_views#querying-views) of the Virtual DataPort Administration Guide.
Hope this helps!