Object access method
programming function available in z/OS
Object access method (OAM) is an access method under z/OS which is designed for the storage of large numbers of large files, such as images. It has a number of distinguishing features, e.g. compared to VSAM:
OAM datasets do not have an internal record structure; they are accessed as binary data streams.
OAM datasets are not directly cataloged. Rather, they are stored into OAM collections, with only the OAM collection being cataloged. The reason for this is to prevent the catalog from being overloaded with large numbers of (e.g. image) files.
OAM is used in conjunction with IBM Db2. An example use case for OAM would be storing medical images in a Db2 database running under z/OS.
History
OAM was created in the 1980s "as a prototype product for an insurance company to replace microfiche." Initially OAM supported optical storage and magnetic disks. In the 1990s support for magnetic tape was added.
The public source identifies “Object access method” as programming function available in z/OS. This brief keeps that definition visible, then builds a research path around Object, access and method.
Why this record matters
A short description can identify a subject without explaining its stakes. For “Object access method”, the useful work is to connect “programming function available in z/OS” to the records capable of establishing context and consequence.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Jul 19, 2025. The linked authority identifier is Q2011687. None of the 0 selected statements returned an explicit reference.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Object access method”, its source revision and the description used here.
- Expand the search: follow Object access method primary sources, Object access method archive and Object research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Object access method”?
- Which cited source is closest to the event, object or claim?
- Which institution is responsible for the underlying evidence?
Search terms from this dossier
This entry incorporates text from “Object access method” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.