
142
6.1
What Are Partitioning and Parallel Processing?
tions. Since hash partitioning does not provide a business perspective
split, it is more useful in terms of improving internal I/O perfor-
mance, such as when processing multiple partitions in parallel. Good
uses for hash partitioning include very large, unmanageable tables;
tables requiring frequent reindexing; unevenly distributed range or
list values creating skewing across partitions sizes; or any situation
where an even physical spread is important. Hash partitioning is
often most useful in getting good performance for partitioning prun-
ing and partition-wise joins (see later in this chapter) ...