Abstract: Domain indexes (indexes created and maintained by user-defined indexing schemes) are managed on partitioned database objects that store data using a system-managed approach. Partition maintenance operations performed on the partitioned database objects cause corresponding partition maintenance operations to be performed on the domain indexes. Partition maintenance operations are performed on both the database objects and the indexes by a system-supplied partition manager. Changes in the partition maintenance operations or partitioning methods supplied by the database management system do not affect user-supplied code which is provided by the user-defined indexing scheme. User-supplied code is therefore partition operation-unaware.

Abstract: Disclosed is a method and mechanism for accessing XML data. In one approach, in the case of a schema based document, the structure of the XML document is known apriori and this information can be exploited to store and retrieve the data more efficiently. A Named Access interface or procedure can be defined and associated with elements of the schema. The need for datatype conversions can be eliminated by allowing direct mapping to the intended datatype or the closest matching datatype in the system to which the invention is directed. The storage information can be exploited to provide “direct” access to data based on offset in lieu of a linear traversal. Another aspect is that only the relevant portions need to be even loaded into memory.

Abstract: A method and system of handling document operation requests on documents with large collections and constrained memory is disclosed. In some embodiments, when one or more collection elements of a document are required to be in memory for a document operation, each of the one or more required collection elements not already in the memory are loaded into a collection partition in the memory before the document operation is executed.

Abstract: 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.

Abstract: Techniques and systems are disclosed for storing instances of an opaque type in a database according to a direct path loading approach. According to one aspect, an opaque type implementor registers, with a loader application, routines that the opaque type implementor implements. In response, the loader application associates the opaque type with the routines. The loader application reads data that comprises instances of the opaque type. The loader application determines which routines are associated with the opaque type. The loader application invokes the routines, which create an array for storing instances of the opaque type and populate the array with values specified in the data. The loader application converts the array into a data stream that conforms to the format of the database's data blocks. The loader application then streams the data to a database server, which writes the data directly into data blocks in the database.

Abstract: A method and system for the in-place evolution of XML schemas is disclosed. To automatically evolve an existing XML schema, a schema evolver receives both an existing XML schema and an XML document as input. The XML document indicates changes to be made to the existing XML schema. Based on the existing XML schema and the XML document, the schema evolver evolves the existing XML schema into a new XML schema that incorporates the changes indicated in the XML document. According to one aspect, the schema evolver generates one or more SQL statements based on the new XML schema. The SQL statements, when executed by a database server, cause the database server to evolve database structures that were based on the formerly existing XML schema so that the database structures conform to the new XML schema. This is accomplished “in place,” without copying the data in the database structures.

Abstract: A method and system for evolving XML-schema-based data to conform to an evolved XML schema is disclosed. Based on an existing XML schema and an instance document that is based on the existing XML schema, an XML-schema-independent form of the instance document is generated. Based on a set of specified transformations and the XML-schema-independent form of the instance document, an evolved instance document is generated. The evolved instance document conforms to an evolved XML schema that incorporates changes to the existing XML schema. Techniques described herein are flexible enough to accommodate a wide variety of evolutions to XML schemas.

Abstract: Techniques and systems are disclosed for directly storing semistructured data in a database. According to one aspect, a client application reads data that comprises instances of a parent type. The client application invokes routines associated with the parent type. An array is created for storing instances of the parent type. These routines invoke routines associated with a child type of the parent type. An array is created for storing instances of the child type. The arrays are populated with values specified in the data. According to one aspect, some columns of the arrays may be populated with other values to be stored in hidden columns of database tables. The client application converts the arrays into a data stream that conforms to the format of the database's data blocks. The client application then streams the data to a database server, which writes the data blocks directly into one or more data blocks in the database.

Abstract: Described is a method and system for storing data into a database, where a determination is made if schema metadata that is used to load the data into the database already exists, and where the existing schema metadata is used to load the data into the database if the schema metadata already exists. If the appropriate schema metadata does not exist, then it is generated and cached so that a later load operation for the same schema type will not need to re-generate this information. In this way, the cost to generate the schema metadata is amortized over multiple load operations to load data of the same schema type. The approach is protocol neutral so that multiple different protocol-based loads can operate with the same schema metadata information and load structures.

Abstract: A method and mechanism to execute a query against a partitioned database object. Data processed or created for an earlier partition is maintained even after further processing is performed against a subsequent partition. A shared data object, such as a context object, is maintained to store data from processing the partitions of a partitioned table. Rather than discarding or overwriting the shared data object after processing each partition, the data from a subsequent partition is instead appended to the shared data object.

Abstract: A method and mechanism to improve the response time of a query that is executed against a partitioned database object. Only a subset or portion of the partitions are accessed during each pass through the partitions, in which only the retrieved portions of the partitions are processed, and in which results can be immediately returned for the query. Processing only a subset of a partition in a given pass permits each partition to be processed multiple times, rather than requiring a first partition to be entirely processed before processing a second partition. In one approach, the query includes a statement to order the result set for a query against a partitioned database object that contains a local index.

Abstract: A method and system for optimizing the execution of database statement is described. Optimization of database statements having non-boolean predicates is disclosed. Also disclosed is the determination and use of different granularity levels of information for submitting database statement predicates to optimizer-related functions.

Abstract: Techniques for supporting access controls on application-specific operations performed by an application include receiving first data at a server distinct from the application. The first data describes a first set of privileges for performing a first set of application-specific operations. Second data is also received at the server. The second data associates a first user of the application with a privilege in the first set of privileges. In response to receiving a request at the server from the application, it is determined whether a particular user may have the application perform a particular application-specific operation based on the first data and the second data. The request indicates the particular user and the particular application-specific operation. A response is sent to the application. The response indicates whether the particular user may have the application perform the particular application-specific operation.

Abstract: Techniques for managing multiple hierarchies of data from a single native hierarchy include registering a set of routines for each foreign hierarchy. The set of routines performs a set of operations on data in the hierarchy associated with a node. A user request is received, which indicates a particular operation on particular data that does not correspond to a node of the native hierarchy. Based on the user request, a first operation on a first set of one or more nodes of a first hierarchy that is not the native hierarchy is determined. A particular routine that corresponds to the first operation is selected from a first set of routines registered for the first hierarchy, and is invoked. These techniques allow a user to employ a consistent interface with the native hierarchy to reach data in any of the hierarchies.

Abstract: Techniques for accessing data that resides in a document on a computer-readable medium by a device with device resources of limited resource amount include determining usage for each portion of the document that consumes the device resources of a plurality of portions of the document. Each portion may be accessed independently of a different portion of the document. Based on the usage, a particular portion of the document is selected to cease consuming the device resources. The device resources consumed by the particular portion are released. The techniques allow a document-processing device with limited resources to scale up to process a large document that would otherwise exceed the available resources. This capability is an advantage when first inserting a large XML document, which cannot be fully manifested in available memory, as multiple loadable units into a database or other persistent store.

Abstract: A method and system are provided for allowing users to register XML schemas in a database system. The database system determines, based on a registered XML schema, how to store within the database system XML documents that conform to the XML schema. This determination involves mapping constructs defined in the XML schema to constructs supported by the database system. Such constructs may include datatypes, hierarchical relationship between elements, constraints, inheritances, etc. Once the mapping has been determined, it is stored and used by the database system to determine how to store subsequently received XML documents that conform to the registered XML schema.

Abstract: A hierarchy may be explicitly or implicitly reflected in existing data maintained external to hierarchy structures. Such hierarchies are referred to herein as a “pre-existing hierarchies”. Techniques are described herein for capturing a pre-existing hierarchy in hierarchy structures. After a pre-existing hierarchy has been captured, there exist two independent sets of data that reflect the hierarchy: the external hierarchy definition and the internal hierarchy definition. Changing either hierarchy definition changes the hierarchy. Therefore, to maintain a consistent reflection of the hierarchy, the internal hierarchy definition must be modified in response to changes made to the external hierarchy definition, and the external hierarchy definition must be modified in response to changes made to the internal hierarchy definition. Various techniques are described for maintaining consistency between the two hierarchy definitions.

Abstract: Described is a hierarchical index that captures the hierarchical relationship of a hierarchy emulated by a relational database system. The hierarchical index is implemented, using a database table which contains rows that serve as entries of the hierarchical index. Another table has rows that are associated with nodes in the hierarchy. Each entry in the hierarchal index maps to a row that corresponds to a node in the hierarchy. A node in the hierarchy may be a parent node with one or more child nodes. In this case, the corresponding entry in the hierarchical index contains identifiers which identify other entries in the index, where the other entries correspond to rows associated with child nodes of the parent node.

Abstract: A method and system for optimizing the execution of database statement is described. Optimization of database statements having non-boolean predicates is disclosed. Also disclosed is the determination and use of different granularity levels of information for submitting database statement predicates to optimizer-related functions.

Abstract: A method and mechanism to improve the response time of a query that is executed against a partitioned database object. Only a subset or portion of the partitions are accessed during each pass through the partitions, in which only the retrieved portions of the partitions are processed, and in which results can be immediately returned for the query. Processing only a subset of a partition in a given pass permits each partition to be processed multiple times, rather than requiring a first partition to be entirely processed before processing a second partition. In one approach, the query includes a statement to order the result set for a query against a partitioned database object that contains a local index.