[GitHub] trafodion pull request #1399: [TRAFODION-2909] Add ROLLUP Function for *Traf...

[liuyu000]

Github user liuyu000 commented on a diff in the pull request:

    https://github.com/apache/trafodion/pull/1399#discussion_r162237087
  
    --- Diff: 
docs/sql_reference/src/asciidoc/_chapters/sql_functions_and_expressions.adoc ---
    @@ -6337,6 +6337,300 @@ UPDATE persnl.job
     SET jobdesc = RIGHT (jobdesc, 12);
     ```
     
    +<<<
    +[[rollup_function]]
    +== ROLLUP Function
    +
    +The ROLLUP function calculates multiple levels of subtotals aggregating 
from right to left through the comma-separated list of columns, and provides a 
grand total. It is a an extension to the `GROUP BY` clause and can be used with 
`ORDER BY` to sort the results.
    +
    +```
    +SELECT…GROUP BY ROLLUP (column 1, [column 2,]…[column n])
    +```
    +
    +ROLLUP generates n+1 levels of subtotals and grand total, where n is the 
number of the selected column(s).
    +
    +For example, a query that contains three rollup columns returns the 
following rows:
    +
    +* First-level: stand aggregate values calculated by GROUP BY clause 
without using ROLLUP.
    --- End diff --
    
    Thanks Dave, your comment has been incorporated :)


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