Abstract: Data from a database object are processed. Transaction information for a set of data of the database object is stored separate from the set of data in an allocated storage space, where the transaction information indicates visibility of the set of data to other transactions. A map structure is generated indicating storage of the set of data and the allocated storage space of the transaction information. The transaction information is altered in response to a transaction to the set of data to alter visibility of the set of data. Altering the transaction information is accomplished by providing updated transaction information within a new storage space in accordance with the transaction to the set of data and generating a descriptor for the transaction indicating an existing location of the set of data and the new storage space.

Abstract: Elements of a database object are removed. The database object is stored as a plurality of different object portions, where each object portion is associated with one or more versions of transaction identifiers stored separately from the database object. An oldest transaction identifier is determined for a transaction for which data portions of the database object remains visible. Each object portion is examined and object portions with a threshold amount of data to remove are determined based on a comparison of the transaction identifiers for those object portions and the oldest transaction identifier. Data from the database object are removed in response to a sufficient quantity of data is to be removed from object portions containing the threshold amount of data.

Abstract: Data from a database object are processed. Transaction information for a set of data of the database object is stored separate from the set of data in an allocated storage space, where the transaction information indicates visibility of the set of data to other transactions. A map structure is generated indicating storage of the set of data and the allocated storage space of the transaction information. The transaction information is altered in response to a transaction to the set of data to alter visibility of the set of data. Altering the transaction information is accomplished by providing updated transaction information within a new storage space in accordance with the transaction to the set of data and generating a descriptor for the transaction indicating an existing location of the set of data and the new storage space.

Abstract: Data from a database object are processed. Transaction information for a set of data of the database object is stored separate from the set of data in an allocated storage space, where the transaction information indicates visibility of the set of data to other transactions. A map structure is generated indicating storage of the set of data and the allocated storage space of the transaction information. The transaction information is altered in response to a transaction to the set of data to alter visibility of the set of data. Altering the transaction information is accomplished by providing updated transaction information within a new storage space in accordance with the transaction to the set of data and generating a descriptor for the transaction indicating an existing location of the set of data and the new storage space.

Abstract: Elements of a database object are removed. The database object is stored as a plurality of different object portions, where each object portion is associated with one or more versions of transaction identifiers stored separately from the database object. An oldest transaction identifier is determined for a transaction for which data portions of the database object remains visible. Each object portion is examined and object portions with a threshold amount of data to remove are determined based on a comparison of the transaction identifiers for those object portions and the oldest transaction identifier. Data from the database object are removed in response to a sufficient quantity of data is to be removed from object portions containing the threshold amount of data.

Abstract: Elements of a database object are removed. The database object is stored as a plurality of different object portions, where each object portion is associated with one or more versions of transaction identifiers stored separately from the database object. An oldest transaction identifier is determined for a transaction for which data portions of the database object remains visible. Each object portion is examined and object portions with a threshold amount of data to remove are determined based on a comparison of the transaction identifiers for those object portions and the oldest transaction identifier. Data from the database object are removed in response to a sufficient quantity of data is to be removed from object portions containing the threshold amount of data.

Abstract: Data from a database object are processed. Transaction information for a set of data of the database object is stored separate from the set of data in an allocated storage space, where the transaction information indicates visibility of the set of data to other transactions. A map structure is generated indicating storage of the set of data and the allocated storage space of the transaction information. The transaction information is altered in response to a transaction to the set of data to alter visibility of the set of data. Altering the transaction information is accomplished by providing updated transaction information within a new storage space in accordance with the transaction to the set of data and generating a descriptor for the transaction indicating an existing location of the set of data and the new storage space.

Abstract: Elements of a database object are removed. The database object is stored as a plurality of different object portions, where each object portion is associated with one or more versions of transaction identifiers stored separately from the database object. An oldest transaction identifier is determined for a transaction for which data portions of the database object remains visible. Each object portion is examined and object portions with a threshold amount of data to remove are determined based on a comparison of the transaction identifiers for those object portions and the oldest transaction identifier. Data from the database object are removed in response to a sufficient quantity of data is to be removed from object portions containing the threshold amount of data.

Abstract: Elements of a database object are removed. The database object is stored as a plurality of different object portions, where each object portion is associated with one or more versions of transaction identifiers stored separately from the database object. An oldest transaction identifier is determined for a transaction for which data portions of the database object remains visible. Each object portion is examined and object portions with a threshold amount of data to remove are determined based on a comparison of the transaction identifiers for those object portions and the oldest transaction identifier. Data from the database object are removed in response to a sufficient quantity of data is to be removed from object portions containing the threshold amount of data.

Abstract: Data from a database object are processed. Transaction information for a set of data of the database object is stored separate from the set of data in an allocated storage space, where the transaction information indicates visibility of the set of data to other transactions. A map structure is generated indicating storage of the set of data and the allocated storage space of the transaction information. The transaction information is altered in response to a transaction to the set of data to alter visibility of the set of data. Altering the transaction information is accomplished by providing updated transaction information within a new storage space in accordance with the transaction to the set of data and generating a descriptor for the transaction indicating an existing location of the set of data and the new storage space.

Abstract: Data from a database object are processed. Transaction information for a set of data of the database object is stored separate from the set of data in an allocated storage space, where the transaction information indicates visibility of the set of data to other transactions. A map structure is generated indicating storage of the set of data and the allocated storage space of the transaction information. The transaction information is altered in response to a transaction to the set of data to alter visibility of the set of data. Altering the transaction information is accomplished by providing updated transaction information within a new storage space in accordance with the transaction to the set of data and generating a descriptor for the transaction indicating an existing location of the set of data and the new storage space.

Abstract: Elements of a database object are removed. The database object is stored as a plurality of different object portions, where each object portion is associated with one or more versions of transaction identifiers stored separately from the database object. An oldest transaction identifier is determined for a transaction for which data portions of the database object remains visible. Each object portion is examined and object portions with a threshold amount of data to remove are determined based on a comparison of the transaction identifiers for those object portions and the oldest transaction identifier. Data from the database object are removed in response to a sufficient quantity of data is to be removed from object portions containing the threshold amount of data.

Abstract: Embodiments relate to a linked list for memory allocation. An aspect includes maintaining a linked list of address ranges in a computer memory that are available for allocation. Another aspect includes receiving a request for allocation of a first address range, the request comprising a size of the first address range. Another aspect includes traversing the linked list to determine an available address range having a size that is greater than or equal to the size of the first address range. Another aspect includes determining whether there is interference in the linked list. Another aspect includes, based on determining that there is no interference in the linked list, removing determined address range from the linked list. Another aspect includes, based on determining that there is interference in the linked list, restarting the traversing of the linked list.

Abstract: Embodiments relate to a linked list for memory allocation. An aspect includes maintaining a linked list of address ranges in a computer memory that are available for allocation. Another aspect includes receiving a request for allocation of a first address range, the request comprising a size of the first address range. Another aspect includes traversing the linked list to determine an available address range having a size that is greater than or equal to the size of the first address range. Another aspect includes determining whether there is interference in the linked list. Another aspect includes, based on determining that there is no interference in the linked list, removing determined address range from the linked list. Another aspect includes, based on determining that there is interference in the linked list, restarting the traversing of the linked list.

Abstract: Methods and apparatus provide an adaptive load balancer that presents a virtual data system to client computer systems. The virtual data system provides access to an aggregated set of data, such as files or web service objects, available from a plurality of server data systems respectively operating within a plurality of server computer systems. The adaptive load balancer receives a client data access transaction from a client computer system that specifies a data access operation to be performed relative to the virtual data system presented to the client computer system. The adaptive load balancer processes the client data access transaction in relation to metadata associated with the virtual data system to provide access to the file or service object within a server computer system, or to access the metadata.

Abstract: In a network of computer nodes, a directory service provides both the physical location of directory information around the network and the directory information itself in a single data structure. This single data structure is distributed throughout the network, and continuously redistributed, so as to create a directory service that is both more flexible, and more robust, than prior art directory services.

Abstract: A multi-user file storage service and system enable each user of a pre-subscribed user group to communicate with a remote file server node via a wide area network and to access the files of the file group via the respective client node. More than one user of the pre-subscribed user group is permitted to access the file group at the remote file server node simultaneously. Integrity of the files at the remote file server node are maintained by controlling each access to each file at the remote file server node so that each access to files at the remote file server is performed, if at all, on a respective portion of each file as most recently updated at the remote file server node. Additionally, an encrypted key is transferred from the file server node to a particular client node via a secure channel. The encrypted key uses an encryption function and a decryption function not known locally at the remote file server.

Abstract: A multi-user file storage service and system enables each user of a user group to operate an arbitrary client node at an arbitrary geographic location to communicate with a remote file server node via a wide area network. More than one user of the user group is permitted to access the file group at the remote file server node simultaneously, but the integrity of the files is maintained by controlling access so that each access to one of the files at the remote file server is performed, if at all, on a respective portion of that file as most recently updated at the remote file server node.

Abstract: A method and system are provided for optimizing the local caching of one or more data components available from a server node. Each of plural nodes connected to a local area network is provided with a locally physically present cache. Each of the caches of at least some of the plurality of nodes are linked together into a single virtual cache. A particular one of the nodes is designated as a repository node for persistently storing a particular data component and for providing a copy of the particular data component to other referencing nodes of the plurality of nodes which lack, but which desire to access, the particular data component. Designation of the particular node as the repository node is unchanged solely by providing a copy of the particular data component to one of the referencing nodes that desires to access the particular data component. The repository function of a node for a particular data component is relatively static.

Abstract: In a network of computer nodes, a directory service provides both the physical location of directory information around the network and the directory information itself in a single data structure.