摘要:
Various techniques are provided for facilitating the management of hierarchical data within a relational database system. One such technique involves separating the storage structures used to store data that captures the information about the hierarchy (the “hierarchy structures”), from the storage structures used to store the content of the resources that belong to the hierarchy (the “content structures”). Techniques are also provided for allowing users to customize the metadata attributes associated with resources that belong to the information hierarchy. One technique involves registering XML schemas that specify the metadata attributes desired by a user. Another technique involves storing attributes that do not correspond to any declared field in a “catch-all” column within the resource table. Techniques are provided for determining how to store resources as they are added to the database. According to one technique, the database server searches the data of the resource to find content-type information. If content-type information is found, then the database server consults a content-type to content-structure mapping to determine where to store the content of the resource.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A method and apparatus for processing path-based database operations is provided. According to one aspect, a path cache is maintained. For each hierarchical node that is traversed during a path-determining operation, it is determined whether a cache entry corresponding to that node is already contained in the path cache. If such a cache entry is already contained in the path cache, then the path indicated in that cache entry is used to complete the pathname for the node for which the operation is being performed. As a result, hierarchically higher nodes do not need to be traversed to complete the operation. Alternatively, if such a cache entry is not already contained in the path cache, then a cache entry for the node currently being traversed is generated and inserted into the path cache for use in subsequent path-determining operations.
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 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:
Business logic is integrated within a repository through the use of “resource configurations.” A resource configuration is a unit of business logic that is supplied by a user to the repository and associated with a particular directory and/or a resource. Each resource configuration contains one or more configuration items that each defines and/or expresses one or more business rules for managing a resource associated with the resource configuration.
摘要:
A method and apparatus for performing an action in response to a file system event is provided. According to one aspect, sets of “event listeners” are associated with a file hierarchy and/or the nodes thereof. Each event listener contains a set of “event handlers.” Each event handler corresponds to a separate type of event that may occur relative to the file hierarchy's nodes. When an event is going to occur relative to the hierarchy or a node thereof, all event listeners that are associated with that hierarchy/node are inspected to determine whether those event listeners contain any event handlers that correspond to the event's type. Those event handlers that correspond to the event's type are placed in an ordered list of event handlers to be invoked. As the event handlers in the list are invoked, programmatic mechanisms that correspond to those event handlers are executed to perform customized user-specified actions.