Abstract: A mechanism is described for allowing third party client applications to affect how high-level document commands are implemented in a database. After a high-level document command meeting certain criteria is received in a database management system, the system identifies one or more third party client application that are to be notified when such high-level document commands are received. The client applications are then notified allowing the client application to return implementation instructions which are used by the database management system in determining how to implement the high-level document command. The instruction may be to prevent implementation altogether, to somehow change the implementation, or even to perform high-level document commands in addition to the original high-level document command.

Abstract: A mechanism is described for the reliable notification to client applications of the implementation of predefined high-level document commands in a database. The database management system is issued a number of high-level document commands such as “move electronic mail message” or “add folder” which are to be implemented in the underlying database. As each high-level document command is implemented, an entry representing the high-level document command is set in a notification table stored in a persistent memory such as the database. The appropriate notification is then dispatched to any subscribing client applications. The client application then acknowledges to the database application that the notification has been received. In response, the entry is deleted in the notification table in the database. If the database management system were to fail, the system would check the notification table to see what notification it should send upon restarting.

Abstract: A technique for representing the structure of hierarchically-organized data in a non-hierarchical data structure, such as a relation. The hierarchically-organized data is represented as a tree, and each node in the tree is assigned a position identifier that represents both the depth level of the node within the hierarchy, and its ancestor/descendant relationship to other nodes. The data represented by each node, as well as its position identifier, is stored in a row of a relational database, thereby capturing the hierarchical structure of the data in such relational database. A technique is provided for the compressed storage of position identifiers in a format that allows an efficient bytewise comparison of position identifiers to determine relative order and ancestry.

Abstract: A method and system for generating unique and human-readable URLs for objects included in a network system. When an object is created in a network system it may be that the application creating the object is unaware of URLs. However, it may also be that other applications included on the network system access object using URLs. When it is determined that an object needs a URL, one or more human-readable properties of the object are used to generate a URL. One or more storage locations associated with previously generated URLs are searched to determine if the human-readable properties of the object will generate a unique URL. If it is determined that the human-readable properties of the object will generate a unique URL, then a URL using the human-readable properties of the object is generated. However, if it is determined that the human-readable properties of the object will not create a unique URL, then the URL created using the human-readable properties is modified so that it is unique.

Abstract: The present invention increase the efficiency of virtual memory usage when performing heap allocation and reduces virtual memory fragmentation caused by heap allocation. Instead of incrementally growing the initial heaps when there is not enough heap memory to make an allocation, an entirely new heap is created in which to make the allocation. That new heap may be added to the pool of heaps from which an allocation may be made. The additional heaps are of a constant, relatively large, size thereby reducing the risk of virtual memory fragmentation.

Abstract: A Web crawler creates an index of documents in a document store on a computer network. In an initial crawl, the crawler creates a first full index for the document store. The first full crawl is based on a set of predefined “seed” URLs and crawl restrictions, and involves recursively retrieving each folder/document directly or indirectly linked to the seed URLs. In the process of creating the first full index, the crawler creates a History Table containing a list of URLs for each folder and document found in the first full crawl. The History Table also includes a local commit time (LCT) for each document and a deleted documents count (DDC) and LCT or maximum LCT (MLCT) for each folder (this assumes that the store supports a folder hierarchy and the MLCT, LCT and DDC properties). Thereafter, in an incremental crawl, the crawler determines, for each folder, (1) whether the DDC for that folder has changed and (2) whether the MLCT is more recent than the corresponding value in the History Table.

Abstract: A technique for representing the structure of hierarchically-organized data in a non-hierarchical data structure, such as a relation. The hierarchically-organized data is represented as a tree, and each node in the tree is assigned a position identifier that represents both the depth level of the node within the hierarchy, and its ancestor/descendant relationship to other nodes. The data represented by each node, as well as its position identifier, is stored in a row of a relational database, thereby capturing the hierarchical structure of the data in such relational database. A technique is provided for the compressed storage of position identifiers in a format that allows an efficient bytewise comparison of position identifiers to determine relative order and ancestry.

Abstract: A Web crawler application takes advantage of a document store's ability to provide a content identifier (CID) having a value that is a unique function of the physical storage location of a data object or document, such as a Web page. In operation, the crawler first tries to fetch the CID for a document. If the CID attribute is not supported by the document store, the crawler fetches the document, filters it to obtain a hash function, and commits the document to an index if the hash function is not present in a history table. If the CID is available from the document store, the CID is fetched from the document store. The crawler then determines whether the CID is present in the history table, which indicates whether an identical copy of the document in question has already been indexed under a different URL.

Abstract: A computer system data container such as a directory or data folder includes various items (e.g., e-mail messages) having item level security controls. In this invention, the computer system ignores files for which the viewer has no viewing rights when summary data about the data container is displayed on the viewer's monitor. For each item level security setting, a running total is kept of an aggregate property (e.g., count of, size of) of all the items in the directory or folder of that security setting. Changes to the running total occur as items are added or deleted, or edited if the aggregate property is the size of all items of that security setting. Regardless of what the aggregated data is, the computer system adds only the running totals for which the user has viewing rights when computing summary data. Thus, the user cannot infer anything about non-viewable items from the summary data.

Abstract: The present invention increase the efficiency of virtual memory usage when performing heap allocation and reduces virtual memory fragmentation caused by heap allocation. Instead of incrementally growing the initial heaps when there is not enough heap memory to make an allocation, an entirely new heap is created in which to make the allocation. That new heap may be added to the pool of heaps from which an allocation may be made. The additional heaps are of a constant, relatively large, size thereby reducing the risk of virtual memory fragmentation.

Abstract: Systems and methods for enforcing access control on secured documents that are stored outside of the direct control of the original application that would normally store and govern access to the documents. Access security can be enforced at a search engine associated with an indexing system that compiles references to documents at any number of network locations. The search engine discloses to the requesting user only those documents that the user is authorized to read. If a document is identified for potential disclosure to a user, and the document's source location has an access control system that is not directly interoperable with a native access control system of the search engine, a security provider at the search engine enforces access control. The security provider, in cooperation with the source location of the document, converts the user context that identifies the requesting user to a format that can be used by the security provider.