November 2008
Intermediate to advanced
591 pages
17h 28m
English
Another way of categorizing functions is in terms of whether they operate on values from just one row at a time, on values from a collection, or on a set of rows. Aggregate functions operate against a collection of values and return a single summarizing value. Scalar functions return a single value based on scalar input arguments. Some scalar functions, such as CURRENT_TIME, do not require any arguments.