The following bug has been logged on the website:
Bug reference: 14132
Logged by: Reynold Smith
Email address: fiercetuba(at)protonmail(dot)com
PostgreSQL version: 9.5.2
Operating system: Linux
Description:
This fails, but change bigint to int and it works fine.
```
CREATE TABLE testtable(
a serial PRIMARY KEY,
b bigint,
c bigint
);
CREATE UNIQUE INDEX super_unique_idx ON testtable( COALESCE(b, 0),
COALESCE(c, 0));
INSERT INTO testtable(b, c)
VALUES (1, 2)
ON CONFLICT ((COALESCE(b, 0)), (COALESCE(c, 0))) DO NOTHING;
```