Ah. UNION ALL is the right way to do this query since you are counting two very different things. My query needs an outer join to cover posts that don’t have an entry in discourse_reactions_reactions. Adding that caused my query to time out, so I can’t verify that solves the problem. Union is the right answer here in any case.
I’m a bit curious if post_actions might overcount likes, though. Does it account for people liking a post and then removing or changing that reaction?
I needed to change ‘heart’ to ‘+1’ in the query since we used 
for our likes at College Confidential. Here’s my result from that query:
| reaction | count |
|---|---|
|
2089798 |
 |
28167 |
 |
27070 |
 |
24676 |
 |
24055 |
 |
16778 |
 |
5325 |
 |
4590 |
 |
3547 |
 |
3078 |
 |
2623 |
 |
2443 |
 |
369 |
 |
43 |