How many people in my Mastodon feed also tweeted today?

I lasted tweeted on Dec 22. (It was, unsurprisingly, a link to a blog post about Mastodon.) Today I wondered what percentage of the people who appear in my Mastodon timeline today also appeared on Twitter today.

To start, I wrote this query which tries to match Twitter and Mastodon usernames. When it finds a match, it reports the day on which that person last tweeted.

with mastodon as (
  select
    substring(username from 1 for 15) as username, -- twitter names are max 15 chars
    'from:' || substring(username from 1 for 15) as query -- we will query twitter using, e.g., 'from:judell'
  from
    mastodon_toot
  where
    timeline = 'home'
  limit
    500
)
select
  m.username as mastodon_person,
  t.author->>'username' as twitter_person,
  max(to_char(t.created_at, 'YYYY-MM-DD')) as last_tweet_day
from 
  mastodon m
left join
  twitter_search_recent t -- see https://hub.steampipe.io/plugins/turbot/twitter/tables/twitter_search_recent
on
  t.query = m.query
group by
  mastodon_person,
  twitter_person
order by
  last_tweet_day desc

This is my favorite kind of Steampipe query: two different APIs, each represented as a Postgres table, combined with a SQL JOIN.

The result looks like this, with nulls for failed matches.

+-----------------+-----------------+----------------+
| mastodon_person | twitter_person  | last_tweet_day |
+-----------------+-----------------+----------------+
| AlanSill        | null            | null           |
| Colarusso       | null            | null           |
| ...                                                |
| williamgunn     | null            | null           |
| xian            | null            | null           |
| ...                                                |
| futurebird      | futurebird      | 2022-12-29     |
| glynmoody       | glynmoody       | 2022-12-29     |
| ...                                                |
| khinsen         | khinsen         | 2022-12-23     |
| blaine          | blaine          | 2022-12-23     |
+-----------------+-----------------+----------------+

Next I created a table from the above query.

create table public.mastodon_twitter as 
  -- sql as above

And then ran this query.

select
  last_tweet_day,
  count(*)
from
  mastodon_twitter
where
  last_tweet_day is not null
group by
  last_tweet_day
order by
  last_tweet_day desc

Here’s the result.

+----------------+-------+
| last_tweet_day | count |
+----------------+-------+
| 2022-12-29     | 36    |
| 2022-12-28     | 6     |
| 2022-12-27     | 1     |
| 2022-12-26     | 1     |
| 2022-12-25     | 2     |
| 2022-12-23     | 2     |
+----------------+-------+

The 500 toots represented here were created by 93 people who tooted today.

select count(*) from mastodon_twitter

+-------+
| count |
+-------+
| 93    |
+-------+

Of those 93 people, 48 have matching usernames.

select count(*) from mastodon_twitter where last_tweet_day is not null

+-------+
| count |
+-------+
| 48    |
+-------+

Of the 48 with matching usernames, 36 also tweeted today.

So there’s my answer: 75% of the people who appeared in my Mastodon home timeline (when I sampled it just now) also appeared on Twitter today.

—
1 https://blog.jonudell.net/2022/11/28/autonomy-packet-size-friction-fanout-and-velocity/
2 https://blog.jonudell.net/2022/12/06/mastodon-steampipe-and-rss/
3 https://blog.jonudell.net/2022/12/10/browsing-the-fediverse/
4 https://blog.jonudell.net/2022/12/17/a-bloomberg-terminal-for-mastodon/
5 https://blog.jonudell.net/2022/12/19/create-your-own-mastodon-ux/
6 https://blog.jonudell.net/2022/12/22/lists-and-people-on-mastodon/
7 https://blog.jonudell.net/2022/12/29/how-many-people-in-my-mastodon-feed-also-tweeted-today/
8 https://blog.jonudell.net/2022/12/31/instance-qualified-mastodon-urls/
9 https://blog.jonudell.net/2023/01/16/mastodon-relationship-graphs/
10 https://blog.jonudell.net/2023/01/21/working-with-mastodon-lists/
11 https://blog.jonudell.net/2023/01/26/images-considered-harmful-sometimes/
12 https://blog.jonudell.net/2023/02/02/mapping-the-wider-fediverse/
13 https://blog.jonudell.net/2023/02/06/protocols-apis-and-conventions/
14 https://blog.jonudell.net/2023/02/14/news-in-the-fediverse/
15 https://blog.jonudell.net/2023/02/26/mapping-people-and-tags-on-mastodon/
16 https://blog.jonudell.net/2023/03/07/visualizing-mastodon-server-moderation/
17 https://blog.jonudell.net/2023/03/14/mastodon-timelines-for-teams/
18 https://blog.jonudell.net/2023/04/03/the-mastodon-plugin-is-now-available-on-the-steampipe-hub/
19 https://blog.jonudell.net/2023/04/11/migrating-mastodon-lists/
20 https://blog.jonudell.net/2023/05/24/when-the-rubber-duck-talks-back/