IBM DevOps Code ClearCase: Difference between revisions

Revision as of 05:31, 1 April 2005

Revision as of 15:33, 5 June 2005

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== Views ==

Objects under version control in ClearCase are stored in repositories called '''VOBs''' ('''v'''ersioned '''o'''bject '''b'''ase). ClearCase's novelty was in its versioned file system (called MVFS: '''M'''ulti'''v'''ersion '''F'''ile '''S'''ystem), which can be mountedused to mount VOBs as a virtual file system through a ''dynamic view'', selecting a consistent set of versions and allowing for the production of [[Derived Object|derived objects]]. The dynamic view allows this to map to a [[Software Configuration]]. This was a departure from the ''repository''/''sandbox'' model, allowing for the early management of artifacts (before they are being checked in, and not limited to these first order configuration items).

Alternatively, ClearCase supports ''snapshot views'' which are just copies of a directory tree spanning one or several VOBs. Snapshot views do not use a virtual file system to provide access to VOB data. Instead, a snapshot view stores a copy of the VOB data locally on the user's computer. Snapshot views can be used while disconnected from the network and later resynchronized to the VOB when a connection is reestablished. This mode of operation is similar to how the widely-used [[Concurrent Versions System|CVS]] (Concurrent Versions System) software works.