Abstract: A system and method for joining a build table to a probe table in response to a query for data includes executing a hash loops join of the build table and the probe table. Matched rows are joined and output when the rows match each other by satisfying a join predicate. In an outer join, unmatched rows in the probe table are joined to a NULL build table field values and output, such that all rows of the probe table are output regardless of whether they have matched rows in the build table. In an early-out join, on the other hand, a “match once” table defines the probe table and in response to a query for unique probe table outputs, the joining of a probe table row, once joined and output a first time, to any other rows in the other table is prevented regardless of whether the row might match other rows. In both the hash loops early-out join and the hash loops outer join, when the build table is larger than main memory, the roles of the build and probe tables are reversed.

Abstract: A system and method for joining a build table to a probe table in response to a query for data includes over partitioning the build table into “N” build partitions using a uniform hash function and writing the build partitions into main memory of a database computer. When the main memory becomes full, one or more partitions is selected as a victim partition to be written to disk storage, and the process continues until all build table rows or tuples have either been written into main memory or spilled to disk. Then, a packing algorithm is used to initially designate never-spilled partitions as “winners” and spilled partitions as “losers”, and then to randomly select one or more winners for prospective swapping with one or more losers. The I/O savings associated with each prospective swap is determined and if any savings would be realized, the winners are designated as losers the losers are designated as winners. The swap determination can be made multiple times, e.g.

Abstract: A system and method for finding an .epsilon.-approximate .phi.-quantile data element of a data set with N data elements in a single pass over the data set. The .epsilon.-approximate .phi.-quantile data element is guaranteed to lie within a user-specified approximation error .epsilon. of a true .phi.-quantile data element being sought. B buffers, each having a capacity of k elements, initially are filled with sorted data elements from the data set, with the values of b and k depending on .epsilon. and N. The buffers are then collapsed into an output buffer, with the remaining buffers then being refilled with data elements, collapsed (along with the previous output buffer), and so on until the entire data set has been processed and a single output buffer remains. A data element of the output buffer corresponding to the .epsilon.-approximate .phi.-quantile is then output as the approximate .phi.-quantile data element.

Abstract: A system and method for a relational database system for identifying star joins in a query and for breaking the query down for bitmap ANDing. The fact table of the star join is located, and cycles between and within dimension tables are broken. Then, the minimal set of tables necessary to execute the star join is identified, and the dimension tables that should appear in the bitmap ANDing plan are also identified. A bitmap ANDing plan is then generated, or, if the query does not qualify for bitmap ANDing, a conventional execution plan is generated.

Abstract: A method, apparatus, and article of manufacture for a computer implemented storage mechanism for persistent objects in a database management system. A statement is executed in a computer. The statement is performed by the computer to manipulate data in a database stored on a data storage device connected to the computer. It is determined that an object is to be stored in an inline buffer. When the object can be entirely stored in the inline buffer, the object is stored in the inline buffer. When the object cannot be entirely stored in the inline buffer, a selected portion of the object is stored in the inline buffer and the remaining portion of the object is stored as a large object.

Abstract: A method of operating a switched communications network redirects certain types of messages away from the switch to free up switch resources for other messages, thereby decreasing the size of switch needed or delaying necessary switch size upgrading. Messages are redirected by intelligent concentrators that can connect certain types of messages to their destinations without routing them through the switch. For example, messages between an origination and a destination connected to the same concentrator need not be sent through the switch. Similarly, messages between originations and certain high-volume, long-duration destinations such as data service gateways can be connected directly without passing through the switch. The intelligent concentrators communicate with the switch on a control channel so that the switch remains aware of the status of each origination or destination (e.g., so that it knows not to attempt to route messages to an origination or destination that is in use).

Abstract: Unwieldy star/join queries are performed more efficiently using a filtered fact table. Suitable queries include star/join queries with a large fact table joined with multiple subsidiary dimension tables, where indices exist over fact table join columns. The query is analyzed to prepare a query plan for the dimension table accesses. This plan is supplemented by adding nested loop join operations, where the inner table is a dimension table plan and the outer table is an index scan performed over a fact table index of the join column with the dimension table. The plan is also supplemented by filtering records resulting from the nested loop joins using a sequence of dynamic bit vectors, ultimately yielding a list of probable fact table records. The plan is further supplemented by fetching these records to construct a distilled fact which is used, instead of the large original table, to execute the query in considerably less time.

Abstract: The system, method, and program of this invention avoids potential write/write conflicts and read/write conflicts when a subcomponent of a composite object (e.g., an ADT) is mutated. The embodiments of this invention define a copy semantic for the mutation function. In one embodiment, a copy function is inserted prior to any mutation function. In a another embodiment, a global compile-time analysis is performed to determine if a write/write or read/write conflict exists; and to eliminate redundant copy constructors if a conflict does exist. In a preferred embodiment, only a local analysis is performed during the parsing phase, thereby avoiding a global compile-time analysis. A mutation safe flag is associated with each parse tree node. A read target leaf parse tree node is set to false while non-leaf parse tree nodes (functions) derive their value from an incoming node, except that constructors and copy constructor functions are always true. Whether or not a copy is made of the composite object (i.e.

Abstract: Programming language systems commonly allow for the use of function calls within a body of program source code. Since function names are generally descriptive, it is sometimes the case that two different functions ("function instances") will have the same name, and be distinguishable by having either a different number of arguments ("arity"), or arguments of different types. Both at compile time and at run time, the possibility of error exists if there is a mismatch between the arguments required by a function and the arguments provided to the function by the function call. Methods and related apparatus, for use in programming language systems, are set forth which support compile-time type checking and run-time dispatch for overloaded functions in an environment supporting subtypes with multiple inheritance.

Abstract: Methods and related apparatus, for use in programming language systems, are set forth which support compile-time type checking for overloaded functions in an environment supporting subtypes with multiple inheritance. At both compile and runtime, the invention considers the type of all actual arguments of a function to select a proper function instance to execute. Furthermore, the methods contemplated by the invention identify at compile time the set of function instances which might be invoked due to subtype substitutions for the actual arguments. Since type errors on function invocations or variable assignments are usually indicative of a programming error, program reliability can be improved and faults that would otherwise result in runtime errors can be corrected through the use of the invention prior to program deployment.

Abstract: A retrievable packer is provided for wireline setting and tubing retrieval. A circumferentially extending shear member releases the retrievable packer from the wireline once the retrievable packer is set. A positive locking member releasably locks the upper and lower slips to the mandrel as they are wedged into gripping engagement with the casing string. The positive locking member includes a body lock ring which locks the upper slip assembly in a ratcheting engagement with the packer mandrel, and a J-latch which releasably secures the lower slip assembly to the mandrel.

Abstract: An actuator for actuating a downhole mechanism in a well utilizes increased annular pressure in one instance, and a control line pressure in a second instance. The actuator has an actuating chamber in which an actuating piston moves. The actuating piston communicates with the annulus pressure on one side and with pressure in an intensified pressure chamber on the other side. A control valve locates in a control passage leading from the intensified pressure chamber to the actuator piston. A vent valve locates in a vent passage that leads from the actuator piston to the annulus. The vent valve will close when pressure in the intensified pressure chamber exceeds the annulus pressure by a selected amount. Then, at a selected higher pressure, the control valve will open, allowing the pressure in the intensified pressure chamber to act on the actuator piston. A differential area piston will supply the increased pressure in the intensified pressure chamber from the annulus when the actuator is used with a test tool.

Abstract: A cementing apparatus is shown for use with a wireline run setting tool. The apparatus includes a retainer with external gripping and sealing members for sealing off a lower region of the well below the sealing members. The cement retainer has a plurality of cementing ports at the lower end thereof which communicate the interior of the retainer with the lower well region. A sliding valve located within the lower end of the retainer can be moved between open and closed positions to control communication of fluids between the interior of the retainer and the lower well region. An inner body is initially received within the interior of the retainer end is retained in position by means of a collet latch. Actuation of the setting tool sets the gripping and sealing elements of the retainer and moves the inner body to shear the collet latch. This action simultaneously closes the cementing ports by moving the sliding valve within the lower end of the cement retainer.

Abstract: An anchor seal assembly is shown of the type used to anchor tubing within the bore of a surrounding conduit to provide a seal between the conduit bore and the tubing. A threaded connector circumscribes a portion of the exterior of the tubing. The threaded connector has external threads for matingly engaging a threaded interior surface within the bore of the surrounding conduit. The threaded connector is slidingly received within a recess provided within the exterior surface of the tubing. The tubing recess has a shoulder area at one end thereof for contacting an end of the threaded connector and has a ramp area at the opposite end for contacting the opposite end of the connector. Movement of the tubing in one direction relative to the conduit bore causes the threaded connector to contact the tubing recess shoulder area thereby causing the connector to ratchet into engagement with the threaded interior surface within the bore of the surrounding conduit.

Abstract: An adapter kit is shown for attaching a setting tool of the type having a power actuated outer sleeve and a cooperating inner tubular member to a well packer. The adapter kit includes a tubular mandrel having an upper end which is adapted to be connected to the setting tool inner tubular member and has a ramp area formed in a portion of the mandrel exterior. A collet having a collet body and a plurality of expansive collet fingers is slidably received about the tubular mandrel with the ramp area beneath the collet fingers to expand the fingers outwardly with respect to the mandrel. The collet fingers are provided with an outer threaded surface which is adapted to engage a mating internally threaded surface of the well packer when the collet fingers are expanded to the proper thread diameter by passing the mandrel ramp beneath the collet fingers. The collet is releasably secured in position by a shear wire with the fingers in the outwardly expanded position for engaging the packer internally threaded surface.

Abstract: An expendable plug assembly of the type adapted to be received within the bore of a well packer is shown having a shear sleeve and a plug body initially received within the shear sleeve interior. The plug body has a closed end for preventing flow of well fluid through the well packer when the plug body is in place within the shear sleeve. A lock ring is provided for releasably supporting the plug body within the shear sleeve interior. A collet body mounted about the plug body has a collet extension at one end thereof and a plurality of collet fingers at the opposite end thereof. The collet fingers are selectively engagable within the well packer bore to fix the plug assembly within the bore. Shear screws are provided for releasably connecting the collet extension to the shear sleeve. The shear screws are severable by downward movement of the shear sleeve relative to the collet extension.

Abstract: A perforating gun for perforating earth formations, primarily in oil and gas wells. The gun includes a straight metal tube in which explosive jet charges are carried. A mounting apparatus within the tube holds the charges in pairs, the pairs being spaced vertically from each other. The charges within a pair point in the same general direction. The axis of each charge within a pair lies in a common horizontal plane with the axis of the other charge in the pair. The gun is operable with a decentralizer that places it in contact with the casing wall for firing. An alignment device within the gun assures that the charges are all pointing toward the nearest wall.