Returning same row n amount of times.

[slimdave]

You might also try recreating the "fifteen" table as an IOT and analyzing it, which would probably be the practice if it were implemented ... my local results (10g)

union all dual     11
table of integers  13 (heap table)
collection type    9
table function     25
pipelined function 17
group by cube      1743

... and ...

union all dual     11
table of integers  8 (analyzed IOT)
collection type    8
table function     20
pipelined function 12
group by cube      1702

I also tried a hint-less version of all the queries, and got ...

union all dual     8
table of integers  7
collection type    7
table function     20
pipelined function 14
group by cube      1717

The Union-all seems to benefit there.

[padders]

So much for hints then :-(

Thanks for suggestions Dave, good stuff.