Oracle International Corporation

Bhushan Khaladkar

Nipun Agarwal

Sam Idicula

Ravi Murthy

Sabina Petride

Asha Tarachandani

Eric Sedlar

Sivasankaran Chandrasekar

Muralidhar Krishnaprasad

James W Warner

Anand Manikutty

Visar Nimani

Adiel Yoaz

Neema Jalali

Sanket Malde

Syam Sundar Pannala

Tim Wing Yu

Mohammed Irfan Rafiq

Ashwini Surpur

Sivansankaran Chandrasekar

Ellen Batbouta

Deepak Agrawal

Sandeep Mane

Tomas Saulys

Sheng-Yih Guan

Ian Macky

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.

Client processing for binary XML in a database system

Techniques are provided for efficiently collecting statistics for hierarchically-organized collections of data. A database system leverages container-level modification time stamps and stored subtree-level change information to gather statistical information from only those resources in a hierarchical collection for which the statistics have changed since the last time that statistics were gathered for the collection. A lockless data structure is also described for storing the subtree-level change information in which an identifier corresponding to each subtree in a collection containing a changed resource may be stored. This data structure may be a table that is distinct from one or more tables representing the collection. In one embodiment of the invention, the immediate parent resource of a particular modified resource may be omitted from the subtree table by leveraging modification time stamps while gathering statistics based on tracked subtree-level information.

Technique to gather statistics on very large hierarchical collections in a scalable and efficient manner

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.

Efficient file access in a large repository using a two-level cache

Techniques are provided to achieve performance improvements for path-based access to hierarchical data and for utilizing an extensible indexing framework. Extensible operators may be optimized by evaluating the operators using functions native to the database system instead of using functions defined through an extensible indexing mechanism. Furthermore, the database system may resolve a resource path of a query when the query is compiled, and may store the mapping of the resource path to one or more resources in a cursor for the query execution plan to avoid resolving the resource path each time the cursor is used to run the query. The cursor may be made dependent on the one or more resources to which the resource path refers at compile time. This takes advantage of the observation that the mapping of the resource path to particular resources rarely changes between evaluations of a particular query.

Techniques for efficient queries on a file system-like repository

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.

Efficient migration of binary XML across databases

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.

Technique for efficiently evaluating a security policy

Techniques for fast and scalable generation and aggregation of XML data are described. In an example embodiment, an XML query that requests data from XML documents is received. The XML query is evaluated to determine one or more XML results. For each particular XML result, evaluating the XML query comprises: instantiating a particular data structure that represents the particular XML result, where the particular data structure is encoded in accordance with tags specified in the XML query but does not store the tags; and storing, in the particular data structure, one or more locators that respectively point to one or more fragments in the XML documents, where the particular data structure stores the one or more locators but does not store the one or more fragments. On demand, in response to a request indicating the particular XML result, a serialized representation of the particular XML result is generated based at least on the particular data structure.

Techniques for fast and scalable XML generation and aggregation over binary XML

Systems, methods, and other embodiments associated with providing an XML-based translation service are described. One method embodiment includes accessing a translation-aware XML document that may comply with a translation-enabling XML schema. The document may store a first XML element that stores translatable data and a second XML element that stores a translation of the translatable data. The schema may describe that the first XML element includes a first identifier that identifies the first element as storing translatable data. The schema may also describe that the second XML element includes a second identifier that identifies the second element as storing a translation for translatable data. The method may also include establishing a session language identifier and providing a virtual view of the translation-aware XML document, the virtual view being determined, at least in part, by the session language identifier.

XML-based translation

Systems, methods, and other embodiments associated with providing query modes for translation-enabled XML documents are described. One method embodiment includes receiving an XPath query to an XML document that may store a translation for a data element. The method embodiment may also include automatically selecting a query mode for the XPath query. The method embodiment may also include querying the XML document using the XPath query and the selected query mode. The query mode may control, at least in part, the operation of an XML database logic.

Query modes for translation-enabled XML documents

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.

Fast path loading of XML data

Techniques are provided for changing data for an XML construct in an SQL/XML compliant database management system (DBMS). The DBMS allows instances of XML type to represent XML constructs, such as XML documents, XML elements, XML attributes, and fragments of XML documents. An SQL statement is received that includes an XML operator that operates on a particular component in an instance of XML type. During execution of the SQL statement, the XML operator is evaluated by modifying content for the component without modifying the entire instance. For example, an XML delete operator deletes the particular component from the instance. Other XML operators include an insert operator, an insert-before operator, an append-child operator, and an update operator. During execution, these operators may be rewritten to operate on existing SQL constructs, or evaluated by updating only some of the existing SQL constructs, or both.

Techniques for changing XML content in a relational database

Described herein are techniques that allow applications developed in non-object oriented languages, such as C, to interact with DOM trees implemented under different DOM implementations. An application accesses different DOM implementations through a set of function pointers that conform to a set of function signatures. The set of function pointers may be stored in a data structure defined to have member function pointers that point to functions that conform to the set of function signatures. The set of function signatures define a common interface through which applications may interact with a variety of DOM implementations. One or more applications generate the set of function pointers and store them in a data structure. The other applications register the function pointers with an application by, for example, passing a pointer to the data structure to the application.

Call back structures for user defined DOMs

Described herein is a system for 'lazy' manifestation of XML documents. In lazy manifestation, only portions of an XML document that contain data of interest (e.g., a particular element or attribute requested by an application) are manifested. The term 'manifesting a portion of an XML document' refers to creating an in-memory representation of the portion and incorporating it into existing in-memory representation of an XML document, if any. These portions are referred to herein as a loadable unit. A loadable unit is a set of one or more nodes in an XML document, where when there is need to manifest a node in the set, other nodes in the loadable unit are manifested too. Loadable units may, but not necessarily, correlate to content structures that store the nodes. A loadable unit may be the nodes whose content is contained in a row.

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Mountain View, CA, United States of America

Bhushan Khaladkar