The author explicitly states that she is using these in SQL Server, but I did a bit of digging and they are supported in ANSI SQL2003/2008, which is implemented

The author explicitly states that she is using these in SQL Server, but I did a bit of digging and they are supported in ANSI SQL2003/2008, which is implemented by all the major vendors (MySQL, PostegreSQL, Oracle, DB2, SQL Server). Wikipedia has some data on support: https://en.wikipedia.org/wiki/Select_(SQL)#Window_function_support_by_RDBMS_vendors https://en.wikipedia.org/wiki/Select_(SQL)#Window_function_s...