The pivot selection is the median of the first, middle, and last
elements; it should be the best choice for sorted data. It's still
possible to pick bad pivots, but data that forces hundreds of
consecutive bad pivot selections should be exceedingly rare. -C
On Jun 4, 2008, at 9:24 AM, Doug Cutting wrote:
Andreas Kostyrka wrote:
java.lang.StackOverflowError
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.compare
(MapTask.java:494)
at org.apache.hadoop.util.QuickSort.fix(QuickSort.java:29)
at org.apache.hadoop.util.QuickSort.sort(QuickSort.java:58)
at org.apache.hadoop.util.QuickSort.sort(QuickSort.java:82)
Quicksort is known to cause stack overflows when sorting large,
already-sorted data. Could that be the issue here?
http://safari.oreilly.com/0201361205/ch07lev1sec3
http://www.finesse.demon.co.uk/steven/sorting.html#quicksort
http://www.seeingwithc.org/topic2html.html
Doug
