Transaction-aware caching for access control metadata
AssigneeOracle International Corporation
InventorsDavid J. Long, David B. Pitfield
Life of this patent
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Abstract
Techniques are provided for performing transaction-aware caching of metadata in an electronic file system. A mechanism is described for providing transaction-aware caching that uses a cache hierarchy, where the cache hierarchy includes uncommitted caches associated with sessions in an application and a committed cache that is shared among the sessions in that application. Techniques are described for caching document metadata, access control metadata and folder path metadata. Also described is a technique for using negative cache entries to avoid unnecessary communications with a server when applications repeatedly request non-existent data.
Claims34
A method for determining authorization to operate on a file, the method comprising the computer-implemented steps of:
- receiving a request, associated with a session, for an operation on the file;
- looking in one or more session caches that are associated with said session for an entry that contains permissions metadata for said file;
- if said entry is not in said one or more session caches, then
- looking for said entry in one or more shared caches whose entries are accessible to multiple sessions;
- and
- if said entry is not in said one or more shared caches, then obtaining said permissions metadata from a source other than said one or more session caches and said one or more shared caches;
- and
- using said permission data to determine whether said operation may be performed on said file.
23 A method for maintaining information about a file managed by a database system comprising the computer-implemented steps of:
- storing within a first cache a first version of an entry that includes only changes made by a transaction associated with said first cache;
- wherein said entry is for permissions metadata;
- storing within a second cache a second version of said entry that does not include said changes made by said transaction;
- and
- invalidating said second version of said entry when said transaction successfully terminates.
The method of claim 23 wherein said first cache is only accessible by said transaction.
The method of claim 23 wherein said transaction is a first transaction that is nested in a second transaction wherein said first cache is associated with said first transaction and said second cache is associated with said second transaction.
A method for finding permissions metadata comprising the computer-implemented steps of:
- maintaining outside of a database system a first cache and a second cache that store said permissions metadata about files stored in said database system;
- wherein said first cache stores a first version of said permissions metadata for a particular file in said database system, wherein said first version reflects modifications made during a first session and does not reflect modifications made during a second session;
- and
- wherein said second cache stores a second version of said permissions metadata for said particular file, wherein said second version reflects said modifications made during said second session and does not reflect said modifications made during said first session.
Dependencies are inferred from the claim text.