unique nulls [not] distinct
BigQuery
Db2 (LUW)
MariaDB
MySQL
Oracle DB
PostgreSQL
SQL Server
SQLite
2015
2017
2019
2021
2023
⊘ 3.5.7 - 3.50.0
⊘ 2008R2 - 2022
✓ 15 - 18
⊘ 8.3 - 14
⊘ 11gR1 - 23.9
⊘ 5.0 - 9.4.0
⊘ 5.1 - 12.0.2