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Description of chaining structures for z/TPFCS and the file system

Question & Answer


Question

Could you see if someone at the TPF Lab has a diagram/description of the chaining structures for TPFCS and the file system? Or, maybe a link to some detailed information.

Answer

z/TPFCS, also known as TO2, is a database that exists on z/TPF. For a conceptual view of the database, see z/TPFCS database layout.

Our product documentation also describes what the different collections that are supported mean and how they look conceptually. As for the internal chaining structures (for example, how z/TPFCS is implemented on a traditional z/TPF database) we don't have anything specific. But we do have information that can give you an idea of how z/TPFCS is implemented on z/TPF; see z/TPF collection support database from a z/TPF system perspective.

This information only talks about the "older" structures that were shipped when TPF collection support was first made available. It does not mention the newer structures that implement collections using FARF6 8-byte file addresses. But for all of the 4-byte address structures discussed in the information, there are analogous structures for 8-byte file addresses with similar names in our code. This information just gives you a starting point for understanding how collections are implemented in z/TPF. You have to work with collections more, and look at the code, to get a deeper knowledge.

The file system is another database that exists on z/TPF and has many flavors, including PFS, FFS which are processor-unique, and MFS which is also processor unique but only exists in memory and is not persistent across an IPL. But many customers use the TFS file system, which is made up of collections.

So z/TPFCS can exist without the file system and is used by other packages (such as MQ) that might not even use the file system. And the file system only uses z/TPFCS to implement the TFS.

For more information about the file system layout see the attached file.

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSZL53","label":"TPF"},"Platform":[{"code":"PF036","label":"z\/TPF"}],"Component":"","Version":"","Line of Business":{"code":"LOB35","label":"Mainframe SW"}}]

Document Information

Modified date:
01 April 2020

UID

dwa1249317

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