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.mastdon_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.

This series:

1. Autonomy, packet size, friction, fanout, and velocity
2. Build a Mastodon dashboard with Steampipe
3. Browsing the fediverse
4. A Bloomberg terminal for Mastodon
5. Create your own Mastodon UX
6. Lists and people on Mastodon
7. How many people in my Mastodon feed also tweeted today?
8. Instance-qualified Mastodon URLs
9. Mastodon relationship graphs
10. Working with Mastodon lists
11. Images considered harmful (sometimes)
12. Mapping the wider fediverse
13. Protocols, APIs, and conventions
14. News in the fediverse