linear data set

{{Short description|IBM data record organization type}}

{{merge|Entry-sequenced data set|Key-sequenced data set|Relative record data set|target=Virtual Storage Access Method|discuss=Talk:Virtual Storage Access Method#Merge suggestion|date=March 2025}}

{{More references|date=September 2017}}

A linear data set (LDS) is a type of data set organization used by IBM's VSAM computer data storage system.{{cite book|url=https://www.redbooks.ibm.com/redbooks/pdfs/sg246105.pdf |series=Redbooks |title=VSAM Demystified |first1=Mary |last1=Lovelace |first2=Jose |last2=Dovidauskas |first3=Alvaro |last3=Salla |first4=Valeria |last4=Sokal |chapter=Chapter 1. VSAM basics |edition=3 |publisher=IBM |date=August 2022}}{{rp|5}}

The LDS has a control interval size of 4096 bytes to 32768 bytes{{cite manual

| title = z/OS 2.5 DFSMS Using Data Sets

| id = SC23-6855-50

| section = Linear Data sets

| section-url = https://www-01.ibm.com/servers/resourcelink/svc00100.nsf/pages/zOSV2R5sc236855/$file/idad400_v2r5.pdf#page=126

| page = 91

| date = September 30, 2021

| url = https://www-01.ibm.com/servers/resourcelink/svc00100.nsf/pages/zOSV2R5sc236855/$file/idad400_v2r5.pdf

| publisher = IBM

}}

in increments of 4096.{{rp|31}} A LDS does not have embedded control information, because it does not contain control information, the LDS cannot be accessed as if it contained individual records.{{Cite web|title=IBM Knowledge Center|url=https://www.ibm.com/support/knowledgecenter/en/SSLTBW_2.1.0/com.ibm.zos.v2r1.idad400/d4261.htm|access-date=2021-02-07|website=www.ibm.com| date=27 March 2014 |language=en-US}}

Addressing within an LDS is by Relative Byte Address (RBA), which allows it to be used by systems such as IBM Db2 or the Operating system.{{huh|date=April 2021}} The benefit of this is that systems such as the OS can access multiple disk spindles and view it as a single storage implementation. The limitations of this, though, is that this does not make this particularly useful to higher level abstraction levels.{{or|date=April 2021}} Data In Virtual{{sfn|ASMGUIDE|loc=Chapter 14. Data-in-virtual|pp=[https://www.ibm.com/servers/resourcelink/svc00100.nsf/pages/zOSV2R5sa231368/$file/ieaa600_v2r5.pdf#page=253 225-248]}} (DIV) and Window services{{sfn|ASMGUIDE|loc=Chapter 17. Window Services|pp=[https://www.ibm.com/servers/resourcelink/svc00100.nsf/pages/zOSV2R5sa231368/$file/ieaa600_v2r5.pdf#page=321 293-310]}} provide an alternative method to direct use of VSAM to access an LDS with a CI size of 4096.