
316 OnDemand SQL Performance Analysis Simplified on DB2 for i5/OS in V5R4
The Temporary Correlated Hash Table icon indicates that a temporary correlated hash table
was created in order to perform hash processing. A hash table is a data structure where the
table data is collated based upon the value of a column or columns referred to as the hash
key. The hash table can then be used to perform probe operation using the hash key to
quickly retrieve all of the table data that matches a particular hash value. Because this is a
correlated hash table, the hash table needs to be rebuilt prior to any scan or probe
operations being performed.
The Corr ...