Self-referencing
merge
BigQuery
Db2 (LUW)
MariaDB
MySQL
Oracle DB
PostgreSQL
SQL Server
SQLite
2005
2007
2009
2011
2013
2015
2017
2019
2021
✓ 2008R2+
b
✓ 15+
a
b
✓ 11gR1+
b
✓ 9.7+
b
✓ 2.0+
b
Doesn’t support
merge
at all
Syntax accepted, functionality not tested thoroughly