摘要:
A two-level cache to facilitate resolving resource path expressions for a hierarchy of resources is described, which includes a system-wide shared cache and a session-level cache. The shared cache is organized as a hierarchy of hash tables that mirrors the structure of a repository hierarchy. A particular hash table in a shared cache includes information for the child resources of a particular resource. A database management system that manages a shared cache may control the amount of memory used by the cache by implementing a replacement policy for the cache based on one or more characteristics of the resources in the repository. The session-level cache is a single level cache in which information for target resources of resolved path expressions may be tracked. In the session-level cache, the resource information is associated with the entire path expression of the associated resource.
摘要:
A system and method for improving performance of join operations is disclosed. The method in one embodiment includes building a graph of vertices and edges, which represent the tables and join conditions for a particular database schema. The method then traverses the graph to find a set of candidate join operations. The method further includes selecting from the set of subset of join operations that makes the best use of a given amount of memory, which means finding a collection of denormalizations which when residing in memory provide the most benefit and the least cost for the given amount of memory. The method then deploys the denormalizations so that current queries in a query processing system can use them instead of actually performing the joins.
摘要:
One embodiment of the present invention provides a system for efficiently evaluating a security policy. During operation, the system retrieves one or more roles associated with the user. Next, the system checks if a session-level cache exists for a set of Access Control Entries (ACEs) which is associated with the one or more roles. If this session-level cache exists, the system returns the set of ACEs from the session-level cache. Otherwise, the system generates the set of ACEs associated with the one or more roles from an Access Control List (ACL). During operation, the system can also update the one or more roles associated with the user and update the set of ACEs based on the updated one or more roles and the ACL. The system subsequently updates the session level cache with the updated set of ACEs and updated one or more roles.
摘要:
One embodiment of the present invention provides a system for efficiently evaluating a security policy. During operation, the system retrieves one or more roles associated with the user. Next, the system checks if a session-level cache exists for a set of Access Control Entries (ACEs) which is associated with the one or more roles. If this session-level cache exists, the system returns the set of ACEs from the session-level cache. Otherwise, the system generates the set of ACEs associated with the one or more roles from an Access Control List (ACL). During operation, the system can also update the one or more roles associated with the user and update the set of ACEs based on the updated one or more roles and the ACL. The system subsequently updates the session level cache with the updated set of ACEs and updated one or more roles.
摘要:
A system and method for improving performance of join operations is disclosed. The method in one embodiment includes building a graph of vertices and edges, which represent the tables and join conditions for a particular database schema. The method then traverses the graph to find a set of candidate join operations. The method further includes selecting from the set of subset of join operations that makes the best use of a given amount of memory, which means finding a collection of denormalizations which when residing in memory provide the most benefit and the least cost for the given amount of memory. The method then deploys the denormalizations so that current queries in a query processing system can use them instead of actually performing the joins.
摘要:
Techniques are provided for transporting subset of databases containing binary XML data. In one embodiment, a method is provided that allows transporting binary XML data that conforms to schema by also transporting the schema entries that are necessary to derive the binary XML. In another embodiment, a method is provided that allows transporting binary XML data that does not conform to schema by also transporting the token tables that contain the mapping for the binary XML.
摘要:
Techniques for implementing fast loading of binary XML into a binary XML database repository are provided. A client application reduces the processing burden on the repository by doing pre-processing of the binary XML data prior to loading.
摘要:
A two-level cache to facilitate resolving resource path expressions for a hierarchy of resources is described, which includes a system-wide shared cache and a session-level cache. The shared cache is organized as a hierarchy of hash tables that mirrors the structure of a repository hierarchy. A particular hash table in a shared cache includes information for the child resources of a particular resource. A database management system that manages a shared cache may control the amount of memory used by the cache by implementing a replacement policy for the cache based on one or more characteristics of the resources in the repository. The session-level cache is a single level cache in which information for target resources of resolved path expressions may be tracked. In the session-level cache, the resource information is associated with the entire path expression of the associated resource.
摘要:
Techniques for implementing fast loading of binary XML into a binary XML database repository are provided. A client application reduces the processing burden on the repository by doing pre-processing of the binary XML data prior to loading.
摘要:
Techniques are provided for transporting subset of databases containing binary XML data. In one embodiment, a method is provided that allows transporting binary XML data that conforms to schema by also transporting the schema entries that are necessary to derive the binary XML. In another embodiment, a method is provided that allows transporting binary XML data that does not conform to schema by also transporting the token tables that contain the mapping for the binary XML.