Population SSL
142 U929-J-Z125-9-76
Size of the hash area for a secondary key
Only in the case of SYSTEM sets can a secondar y key be used for conversion by a hash
routine. UDS/SQL calculates the minimum number of pages required for distributed storage
of record addresses on the basis of the set occurren ce population entry (see the section
“Indirect CALC page” on page 213) and then reserves the number of pag es corresponding
to the next higher prime number.
If some pages overflow due to uneven data distribution by the hash routine, UDS/SQL
automatically sets up overflow pages.
A hash area can be extended at a later time by means of the BREORG utility routine (see
the "Recovery, Information and Reorganization" manual, BREORG).
By default, UDS/SQL sets up a hash area with a size of one page.