Abstract: A method and apparatus for distributing data of a table across a parallel data base system having a plurality of interlinked database nodes. The table is partitioned in accordance with a predetermined partitioning arrangement and data of the table is distributed across a subset of the nodes in accordance with the partitioning arrangement. The partitioning arrangement can comprise horizontal or vertical partitioning. The partitioning arrangement can comprise a partitioning map defining the relationship of partitions of the table to said subset of nodes.

Abstract: Method and means are provided for simulating a contiguous data space within a computer memory, and for placing and accessing data objects of various sizes within the simulated contiguous data space. Multiple, sub-data spaces are concatenated in such a way that each page and each sub-data space in the contiguous data space are uniquely identified. Data objects are placed in the contiguous data space and at the first reference to a page of the data object, only the segment containing the referenced page in the contiguous data space is mapped to the database storage disk. Once a data space page is mapped, the operating system can read the page into memory without requesting a disk operation from the database manager. On modifying a page, if the database disk page location is changed, the contiguous data space page is remapped without changing the page address in the data space.

Abstract: Method and means are provided for simulating a contiguous data space within a computer memory, and for placing and accessing data objects of various sizes within the simulated contiguous data space. Multiple, sub-data spaces are concatenated in such a way that each page and each sub-data space in the contiguous data space are uniquely identified. Data objects are placed in the contiguous data space and at the first reference to a page of the data object, only the segment containing the referenced page in the contiguous data space is mapped to the database storage disk. Once a data space page is mapped, the operating system can read the page into memory without requesting a disk operation from the database manager. On modifying a page, if the database disk page location is changed, the contiguous data space page is remapped without changing the page address in the data space.

Abstract: Method and means are provided for simulating a contiguous data space within a computer memory, and for placing and accessing data objects of various sizes within the simulated contiguous data space. Multiple, sub-data spaces are concatenated in such a way that each page and each sub-data space in the contiguous data space are uniquely identified. Data objects are placed in the contiguous data space and at the first reference to a page of the data object, only the segment containing the referenced page in the contiguous data space is mapped to the database storage disk. Once a data space page is mapped, the operating system can read the page into memory without requesting a disk operation from the database manager. On modifying a page, if the database disk page location is changed, the contiguous data space page is remapped without changing the page address in the data space.

Abstract: A high power current-limiting fuse comprises a cylindrical envelope which closely surrounds a metallic fusible element in the form of a wire or ribbon. The cylindrical envelope is made of high density rigid ceramic such as Alumina of formula Al.sub.2 O.sub.3, and Beryllium oxide of formula BeO. The two ends of the envelope are metalized to form two terminals respectively connected to the ends of the fusible element, whereby the current-limiting fuse is connectable to an electric circuit to be protected through the two so formed terminals. A sheath of fiberglass or ceramic can be mounted around the cylindrical envelope so as to increase the mechanical rigidity of the current-limiting fuse.

Abstract: A high power current-limiting fuse comprises a cylindrical envelope which closely surrounds a metallic fusible element in the form of a wire or ribbon. The cylindrical envelope is made of high density rigid ceramic such as Alumina of formula Al.sub.2 O.sub.3, and Beryllium oxide of formula BeO. The two ends of the envelope are metallized to form two terminals respectively connected to the ends of the fusible element, whereby the current-limiting fuse is connectable to an electric circuit to be protected through the two so formed terminals. A sheath of fiberglass or ceramic can be mounted around the cylindrical envelope so as to increase the mechanical rigidity of the current-limiting fuse.

Abstract: An improved machine is disclosed for assembling high-voltage fuses without an internal core, which fuses comprise at least one fusible element helically wound inside a tubular casing made of electrically insulating material and filled with a pulverulent arc-quenching material. The machine comprises a mobile head comprising a plurality of threaded rods symmetrically mounted about a central axis and whose threads are especially designed for receiving and helically guiding the fusible elements. The rotation of either the whole head or each of the threaded rods about their respective axis is synchronized to the translational movement of a slidable platform on which the head is mounted. In use, the fusible elements are wound in the threads of the threaded rods by rotation of the mobile head about its central axis. Subsequently, the fusible elements are unwound inside the tubular casing by combining a translation of the platform with a rotation of each of the threaded rods of the mobile head at a given ratio.