Parsed test spec with 2 sessions

starting permutation: s1b s1update_nokey s2locktuple s1c
step s1b: BEGIN;
step s1update_nokey: INSERT INTO parttab (key, col1, col2) VALUES (1, 'a', 'b') ON CONFLICT (key) DO UPDATE SET col1 = 'x', col2 = 'y';
step s2locktuple: SELECT * FROM parttab FOR KEY SHARE;
col1|key|col2
----+---+----
a   |  1|b   
(1 row)

step s1c: COMMIT;

starting permutation: s1b s1update_key s2locktuple s1c
step s1b: BEGIN;
step s1update_key: INSERT INTO parttab (key, col1, col2) VALUES (1, 'a', 'b') ON CONFLICT (key) DO UPDATE SET key=1;
step s2locktuple: SELECT * FROM parttab FOR KEY SHARE; <waiting ...>
step s1c: COMMIT;
step s2locktuple: <... completed>
col1|key|col2
----+---+----
a   |  1|b   
(1 row)