|queryType|This String should always be "timeBoundary"; this is the first thing Druid looks at to figure out how to interpret the query|yes|
|dataSource|A String or Object defining the data source to query, very similar to a table in a relational database. See [DataSource](../querying/datasource.html) for more information.|yes|
|bound | Optional, set to `maxTime` or `minTime` to return only the latest or earliest timestamp. Default to returning both if not set| no |