Abstract: A pre-computed result module computes a result prior to receiving a query. The pre-computed result module includes instructions executed by a processor to assess a pre-computation query to designate each identified database source that contributes to the answer to the pre-computation query and corresponding database source metadata. A metadata signature is computed for each identified database source to create a store of identified database sources and corresponding metadata signatures. The query is evaluated to identify accessed database sources responsive to the query. A current metadata signature for each accessed database source is compared to the metadata signatures to identify each updated database source. Re-computed results are formed for each updated database source. Pre-computed results are utilized for each database source that is not updated. A response is supplied to the query using the re-computed results and the pre-computed results.

Abstract: A system has a distributed database with database partitions distributed across worker nodes connected by a network. An analytical view recommendation engine defines an analytical view comprising attributes and measures defined prior to the receipt of a query. The analytical view is maintained as a data unit separate from the distributed database. The analytical view recommendation engine includes instructions executed by a processor to identify a poorly performing report, evaluate queries associated with the poorly performing report, create a recommended analytical view to enhance the performance of the poorly performing report, and deploy the recommended analytical view.

Abstract: A system has worker machines connected by a network. Each worker machine stores at least one partition of a distributed database and a partial function module to initialize a database dimension, increment an aggregate of the database dimension in response to a data change and to serialize a last aggregate of the database dimension in response to a refresh operation to form partial results of an analytical view. An analytical view machine connected to the network responds to a query without accessing a partition of the distributed database. The analytical view machine merges partial results from the worker machines to produce a final result to the query.

Abstract: Methods are provided to write zeroes to logical blocks of a thin-provisioned volume mapped to a deleted file or a dummy file in the host file system. This causes the thin-provisioned volume to map these logical blocks to a common storage space that contains all zeroes so that storage space previously mapped to these logical blocks is free to be reused.

Abstract: To communicate over a SCSI protocol, a first device allocates buffers for a dummy SCSI read command and sends the dummy SCSI read command to a second device. This dummy SCSI read command is not a request by the first device to read data from the second device but instead is an indication that the first device is ready to receive data from the second device. In response, the second device stores the dummy SCSI read command to a command queue until the second device wishes to send data to the first device. At that time, the second device removes the dummy SCSI read command from the command queue and sends a response to the dummy SCSI read command to the first device. This response includes data that the second device wishes to send to the first device. The first device then delivers the received data to a higher layer process.

Abstract: In one embodiment of the invention, a virtual volume is divided into “filled” and “empty” virtual volume (VV) regions. Empty VV regions are mapped to a special zero logical disk that does not consist of any physical disk regions. When a host writes to an empty VV region, a logical disk (LD) region is allocated to the empty VV region so the formerly empty VV region becomes a filled VV region mapped to the allocated LD region. If there are no LD regions available, a new logical disk is created. Additional physical storage can be added to the storage server to create new logical disks as the use of the virtual volume grows. Physical allocation warning points and limits allow the system administrator to be alerted to and to control physical allocation for each individual VV and the set of VVs drawing from the same data allocation control structure (DC).

Abstract: A method is provided to allow a system administrator of a utility storage server to provision virtual volumes several times larger than the amount of physical storage within the storage server. A virtual volume is a virtual representation of multiple disks as a single large volume to a host or an application. In one embodiment, a virtual volume comprises an exception list containing the set of differences from dummy base volume consisting of all zeros. This exception list can be made up of address tables that map virtual volume pages to logical disk pages. As storage demand grows, additional storage is allocated for the address tables and the data pages from separate pools of storage. If any of the pools runs low, more logical disk regions are allocated to that pool.

Abstract: A method is provided to allow a system administrator of a utility storage server to provision virtual volumes several times larger than the amount of physical storage within the storage server. A virtual volume is a virtual representation of multiple disks as a single large volume to a host or an application. In one embodiment, a virtual volume comprises an exception list containing the set of differences from dummy base volume consisting of all zeros. This exception list can be made up of address tables that map virtual volume pages to logical disk pages. As storage demand grows, additional storage is allocated for the address tables and the data pages from separate pools of storage. If any of the pools runs low, more logical disk regions are allocated to that pool.