System and method for cascading data updates through a virtual copy hierarchy
First Claim
1. A method, in a data processing system, for updating metadata in a hierarchy of copies of metadata, comprising:
- updating a first copy of metadata;
identifying a second copy of metadata that is a child copy of the first copy of metadata;
updating the second copy of metadata, in response to the updating of the first copy of metadata, to be consistent with the update to the first copy of metadata; and
wherein the first copy of metadata has a parent copy of metadata, and wherein the parent copy of metadata is not updated in response to the updating of the first copy of metadata.
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Accused Products
Abstract
A system and method for managing data updates by cascading those updates through a virtual copy hierarchy from parent copies to child copies are provided. Virtual copies are created and managed through the use of an instant copy mechanism. Metadata subsets manage both the original data and the copies created by the instant copy mechanism. With an exemplary embodiment of the system and method, changes made to one copy of the data are cascaded to all child copies of the data. In this paradigm not only is the metadata entry for one particular copy changed, but also the corresponding metadata entries of any copies descended from that copy. In an exemplary method, a tree structure is used to maintain a record of all metadata table subsets created by use of an instant copy method. The tree structure can then be searched to find all child copies of a particular copy.
44 Citations
17 Claims
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1. A method, in a data processing system, for updating metadata in a hierarchy of copies of metadata, comprising:
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updating a first copy of metadata; identifying a second copy of metadata that is a child copy of the first copy of metadata; updating the second copy of metadata, in response to the updating of the first copy of metadata, to be consistent with the update to the first copy of metadata; and wherein the first copy of metadata has a parent copy of metadata, and wherein the parent copy of metadata is not updated in response to the updating of the first copy of metadata. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A computer program product stored on a computer readable medium for updating metadata in a hierarchy of copies of metadata, comprising:
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first instructions for updating a first copy of metadata; second instructions for identifying a second copy of metadata that is a child copy of the first copy of metadata; third instructions for updating the second copy of metadata, in response to the updating of the first copy of metadata, to be consistent with the update to the first copy of metadata; and wherein the first copy of metadata has a parent copy of metadata, and wherein the parent copy of metadata is not updated in response to the updating of the first copy of metadata. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. An apparatus in a data processing system for updating metadata in a hierarchy of copies of metadata, comprising:
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said data processing system including a processor executing code for updating a first copy of metadata; a data structure for identifying a second copy of metadata that is a child copy of the first copy of metadata; an update cascade module for updating the second copy of metadata, in response to the updating of the first copy of metadata, to be consistent with the update to the first copy of metadata; and wherein the first copy of metadata has a parent copy of metadata, and wherein the parent copy of metadata is not updated in response to the updating of the first copy of metadata.
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Specification