Proxy access means that the Grafana backend will proxy all requests from the browser, and send them on to the Data Source. This is useful because it can eliminate CORS (Cross Origin Site Resource) issues, as well as eliminate the need to disseminate authentication details to the Data Source to the browser.
Direct access is still supported because in some cases it may be useful to access a Data Source directly depending on the use case and topology of Grafana, the user, and the Data Source.
Click the plus icon to the right to add a function. You can search for the function or select it from the menu. Once
a function is selected it will be added and your focus will be in the text box of the first parameter. To later change
a parameter just click on it and it will turn into a text box. To delete a function click the function name followed
by the x icon.
![](/img/animated_gifs/graphite_query2.gif)
### Optional parameters
Some functions like aliasByNode support an optional second argument. To add this parameter specify for example 3,-2 as the first parameter and the function editor will adapt and move the -2 to a second parameter. To remove the second optional parameter just click on it and leave it blank and the editor will remove it.
You can reference queries by the row “letter” that they’re on (similar to Microsoft Excel). If you add a second query to graph, you can reference the first query simply by typing in #A. This provides an easy and convenient way to build compounded queries.