View source for Telemetry/LongitudinalExamples

Note: There is good background in the [https://gist.github.com/vitillo/627eab7e2b3f814725d2 example notebook] for the longitudinal data set.

Get an overview of the longitudinal data table:
 describe longitudinal_v20160229

That table has a row for each client, with columns for the different parts of the ping.
Some properties are directly available to query on:
 SELECT count(*) AS count
 FROM longitudinal_v20160229
 WHERE os = 'Linux'

=== Arrays ===
Other properties are arrays, which contain one entry for each submission from that client (newest first):
 SELECT element_at(reason, 1) AS last_reason
 FROM longitudinal_v20160229
 WHERE os = 'Linux'

Links:
* [https://prestodb.io/docs/current/functions/array.html Documentation on array functions]

=== Maps ===

Links:
* [https://prestodb.io/docs/current/functions/map.html Documentation on map functions]

=== Examples ===
* Blocklist URLs (extensions.blocklist.url):
 SELECT bl, COUNT(bl)
 FROM
   (SELECT element_at(settings, 1).user_prefs['extensions.blocklist.url'] AS bl
    FROM longitudinal_v20160229)
 GROUP BY bl

* Blocklist enabled/disabled (extensions.blocklist.enabled) count:
 SELECT bl, COUNT(bl)
 FROM
   (SELECT element_at(settings, 1).blocklist_enabled AS bl
    FROM longitudinal_v20160229)
 GROUP BY bl