New Feature: Show locks for a single query analyzed with EXPLAIN

What to do:

add to joe report of the locks obtained by the analysed query

How to implement:

start transaction, execute given query, query pg_locks (not closing transaction), close transaction:

BEGIN
-- Run the analysed query
-- Check which locks are taken
COMMIT

query to get locks data

SELECT l.relation::regclass,
           c.relkind,
           l.locktype,
           l.mode,
           l.granted,
           l.fastpath
    FROM pg_locks l
    JOIN pg_class c ON c.oid=l.relation
    JOIN pg_stat_activity a on l.pid = a.pid
    AND a.query NOT ILIKE '%pg_stat_activity%'
    ORDER BY l.relation ASC;

expected result - something like this

+---------------------------------------+---------+----------+-----------------+---------+----------+
| relation                              | relkind | locktype |      mode       | granted | fastpath |
----------------------------------------+---------+----------+-----------------+---------+----------+
| pg_authid                             | r       | relation | AccessShareLock | t       | f        |
| pg_database                           | r       | relation | AccessShareLock | t       | f        |
+---------------------------------------+---------+----------+-----------------+---------+----------+

UPDATE 2023-07-19: we decided to change the algorithm to avoid observer effects:

begin;
-- Anayze query – with or without execution
-- Get the info about locks form pg_locks, using a different connection (!) to avoid additional locks
commi;