The object access method (OAM) is used to help people access files in the operating system (OS) via certain command line codes. Unlike other access methods that are made for generic systems, the object access method is only fitted to work with the z/OS®, a barebones system used mostly by lawyers and retail stores. OAM is made specifically to help with storing files, and it normally can hold up to 2 gigabytes (GB) of data. Files traditionally are in digital catalogs, but the entire file set itself is cataloged with OAM. Another difference between OAM and other access methods is that all files are recorded as a stream.
There are many access methods used with a range of different OS's, and some are generic, meaning they can be used with several different OS's at once. With the object access method, this can only be used with the z/OS®. This is a 64-bit mainframe OS that does not have an intensive graphical user interface (GUI) but, because it is barebones, it normally can process tasks much faster. While this can be used by many industries, it largely is a favorite of law firms and retail stores.
Based on how it handles files, the main feature of the object access method is to assist in storing a lot of files, such as images, shipping lists, documents and many other computer files. Not only can it store a lot of files, but the files can be rather large. Most mainframe systems can only hold small documents, but OAM can hold up to 2GB because of memory optimization.
When files enter a database or an access method, each file normally is cataloged to make it easier to find. This approach has some advantages, but it takes up a lot of memory. With the object access method, the entire set of files is cataloged as one unit, reducing the memory footprint. A simple search command usually is used to help people find a file in the OAM.
When a traditional access method stores a file, it also makes a record of it in the OS’s database. This takes up memory, as with the catalog, but it also can cause the system to slow down, because it has difficulty processing a high number of documents. To avoid this, the object access method makes each file into a stream, which makes it easier to open and access.