Firebase performance - fetching nodes
<p>Two firebase performance questions:</p>

<ol>
<li><p>Docs refer to flat data is best practice when constructing data. However, if I wish to retrieve a few nodes of data together (a JOIN query in SQL), this means a few network requests. Is Firebase optimizing such use case (in server/client side)? How?</p></li>
<li><p>When fetching a specific node, using its full path, is there any need of indexing it? (Docs refer to actual queries, and I'm not sure this case applies as a query)</p></li>
</ol>

<p>Thanks</p>