Virtual Storage Access Method: Difference between revisions

Revision as of 07:18, 1 December 2020

Revision as of 07:25, 1 December 2020

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While a basic KSDS only has one key (the primary key), alternate indices may be defined to permit the use of additional fields as secondary keys. An Alternate Index (AIX) is itself a KSDS.

The data structure used by a KSDS is nowadays known as a [[B+ tree]].<ref>{{cite web

|url=https://patents.justia.com/patent/9043295

|title=US Patent for Providing record-level alternate-index upgrade locking}}</ref><ref>{{cite web

|url=https://www.wisegeek.com/what-is-vsam.htm

|quote=This index is called a B+ tree.

|title=What is VSAM?}}</ref>

=== Relative VSAM organization ===