摘要:
A method and apparatus for efficiently processing a query that specifies a location path and a content path is provided. The location path identifies the hierarchical location of a set of documents within a resource hierarchy. The content path identifies hierarchical location of one or more nodes within the content of the set of documents. Computing the query includes using a resource hierarchy index, based on the location path, to generate first results corresponding to the set of documents. Computing the query also includes using a content index, based on the content path, to generate second results corresponding to the one or more nodes. Final results of the query are based on the first results and second results by, for example, joining the first and second results.
摘要:
Techniques are provided for encoding/decoding binary XML data in a client program before sending/receiving the XML to/from a database server. By encoding the binary XML at the client, the overhead of parsing the XML text is avoided by the database server, thus improving database server scalability. Also, the XML data is sent by the server to the client in the binary form, and the binary format is decoded by the client program to perform the necessary operations.
摘要:
A method and apparatus for loading an XML document into memory is provided. A client loads one or more array elements into a first partition of an array that is maintained in memory. Each array element represents an XML element of an XML document. Upon determining that an amount of data maintained in the first partition exceeds a first threshold, the client subsequently loads array elements into a new partition of the array. Upon determining that an amount of data maintained in the memory of the client exceeds a second threshold, the array elements of the least recently used partition are persistently stored in a database without persistently storing the entire XML document. When the last XML element of the XML document is loaded into a partition of the array, that partition is persistently stored in the database, thereby causing the entire XML document to be stored in the database.
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.
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:
An XML document can be represented in a compact binary form that maintains all of the features of XML data in a useable form. In response to a request for a modification (e.g., insert, delete or update a node) to an XML document that is stored in the compact binary form, a certain representation of the requested modification is computed for application directly to the binary form of the document. Thus, the requested modification is applied directly to the persistently stored binary form without constructing an object tree or materializing the XML document into a corresponding textual form. Taking into account the nature of the binary form in which the document is encoded, the bytes that actually require change are identified, including identifying where in the binary representation the corresponding actual changes need to be made.
摘要:
In a multi-tier data server system, data from the first tier is cached in a mid-tier cache of the middle tier. Access control information from the first tier for the data is also cached within the mid-tier cache. Caching the security information in the middle tier allows the middle tier to make access control decisions regarding requests for data made by clients in the outer tier.