How PostgreSQL’s
 SQL dialect stays ahead
 of its competitors @MarkusWinand I’m sorry! I couldn’t make it to PgConf.EU in 2014! Don’t repeat my mistake. Come to 
 PgConf.EU 2018 
 in Lisbon! Oct 23-26. How PostgreSQL’s
 SQL dialect stays ahead
 of its competitors @MarkusWinand PostgreSQL 9.5 2016-01-07 GROUPING SETS GROUPING SETS Before SQL:1999 Only one GROUP BY operation at a time: Monthly revenue Yearly revenue SELECT year SELECT year , month , sum(revenue) , sum(revenue) FROM tbl FROM tbl GROUP BY year, month G R O UP BY year GROUPING SETS Before SQL:1999 SELECT year , month , sum(revenue) FROM tbl GROUP BY year, month UNION ALL SELECT year , null , sum(revenue) FROM tbl GROUP BY year