摘要:
Efficient evaluation of resource version history queries is enabled by using a data container storing records corresponding to links between successive versions of a resource. The records include: (a) a record identifier, (b) a predecessor identifier, (c) a successor identifier, (d) a predecessor rowset, which comprises the record identifier of each record in which the predecessor identifier in this record is the successor identifier, and (e) a successor rowset, which comprises the record identifier of each record in which the successor identifier in this record is the predecessor identifier. Depending on the nature of a request, a record is identified in which a particular version is identified by either the predecessor identifier or the successor identifier. Either the predecessor or successor rowsets are recursively read, while the predecessor or successor identifiers corresponding to each record read are added to a result set, thereby forming the ancestor or descendant version history.
摘要:
A method and apparatus for processing a file system operation at a database server is provided. A request to perform a file system operation on a resource stored in a database is received at a database system. The request may be implemented using the NFS protocol. The request may include state identification data that identifies state information associated with the request. State information associated with the request is retrieved within the database system based on the state identification data. State information is information that describes the operational state of the requestor for a particular file. The request is then processed based, at least in part, on the state identification. File system operations may be processed a database management system to access any data, such as a file, relational data, and object-relational data.
摘要:
A method and apparatus for performing network file system (NFS) operations across a plurality of servers is provided. At a first server, a filehandle for a particular file is generated based, at least in part, on an identifier that uniquely identifies the particular file relative to all other files within a file system repository. The file system repository may be implemented in a database. The identifier may also be stored in the database. The first server sends a client the filehandle. The client may thereafter send another request for the performance of a file operation, containing the filehandle, to a different server. The second server may read the filehandle and use the identifier to locate the file within the repository against which to perform the file operation without receiving, from the first server, information that associates the filehandle with the file.
摘要:
A mechanism for querying a label-aware index in the context of versioning is provided. The key of the label-aware index is a composite key and includes a unique label identifier, corresponding to a specific label, and the key of the original index, which key itself may be a composite key. The label-aware index may be implemented as an index-organized table. The label-aware index is organized on disk first by the label identifier and then by the original index key so that queries of versions of resources within a particular label are as efficient as queries on an index of an unversioned repository with the same number of resources.
摘要:
A method and apparatus for performing network file system (NFS) operations across a plurality of servers is provided. At a first server, a filehandle for a particular file is generated based, at least in part, on an identifier that uniquely identifies the particular file relative to all other files within a file system repository. The file system repository may be implemented in a database. The identifier may also be stored in the database. The first server sends a client the filehandle. The client may thereafter send another request for the performance of a file operation, containing the filehandle, to a different server. The second server may read the filehandle and use the identifier to locate the file within the repository against which to perform the file operation without receiving, from the first server, information that associates the filehandle with the file.
摘要:
A method and apparatus for sharing state information among a plurality of servers is provided. A first server receives a request to perform a file operation, such as a NFS file system operation. Thereafter, the first server updates state information to reflect a change in state associated with processing the request. The first server then causes state update information, which identifies the change in state that was made at the first server, to be propagated to a second server. The second server updates state information, stored at the second server, to reflect the change in state associated with processing the request at the first server. Advantageously, a client may send a series of stateful file operations to either the first server or the second server, even if processing any one of the stateful file operation requests requires knowledge of the state of processing prior requests in the series of requests.
摘要:
A database server determines, on an element-level of granularity, what form of VARRAY storage to map collections of elements defined by a XML schema. A collection element may be mapped to an in-line VARRAY or an out-of-line VARRAY. The determination may based on a variety of factors, including the database type mapped to the collection element, database limitations that limit the form storage for certain database types, and annotations (“mapping annotations”) embedded within that XML schema that specifying a database type for database representation of a collection element or a form of VARRAY storage.
摘要:
A method, mechanism, and computer program product for storing, accessing, and managing XML data is disclosed. The approach supports efficient evaluation of XPath queries and also improves the performance of data/fragment extraction. The approach can be applied to schema-less documents. The approach is applicable to all database systems and other servers which support storing and managing XML content. In addition, the approach can be applied to store, manage, and retrieve other types of unstructured or semi-structured data in a database system.
摘要:
A method and system are provided for maintaining an XML index in response to piece-wise modifications on indexed XML documents. The database server that manages the XML index determines which nodes are involved in the piece-wise modifications, and updates the XML index based on only those nodes. Index entries for nodes not involved in the piece-wise modifications remain unchanged.
摘要:
A method and apparatus for facilitating the management of metadata is disclosed, specifically by associating metadata with an XML schema. The database system provides a method that allows end users to maintain additional information describing resources. User-defined metadata attributes are associated as an XML schema which in turn is mapped to a table, referred to as the user metadata table. The XML schema contains user-defined information specifying the metadata that the end-user wants the system to store and maintain. Additionally, a reference is created between an entry in the user metadata table and its corresponding resource entry in the resource table. The resources are accessed directly or by issuing queries against the user metadata table. The querying of the user metadata table gains the benefit of fast and efficient query results and access time.