ROLLUP Analytical function in PostgreSQL.
Currently, there is no version of PG, which supports the rollup. However, people look for this analytical function features. ROLLUP queries result can be achieve using the UNION of Queries. First Let's Understand what does rollup do: If SQL Query has col1,col2,col3,aggregate(col4) then rollup Processing would be something like this. 1. Show the aggregate of col4 as per the col1,col2,col3 2. Then rollup will do the subtotal and will show the result as per the as aggregate of based on col1,col2 3. Then it will show the aggregate/subtotal as per the col1. 4. And at end Total/Sum In short, it creates progressively higher-level subtotals, moving from right to left through the list of grouping columns. Finally, it creates a grand total. In PG, this can be achieve by writing a SubQueries and and UNION those. So, if the rollup query is something like given below: select col1,col2,col3,agg(col4) from relation group by rollup(col1,col2,col3) Then in PG above can be writte