Abstract: Embodiments relate to a method for training an index selection agent for iteratively determining an index set I to be used when running queries against a database, the method being implemented in a computer system. Preferably, the index selection agent is based on Reinforcement Learning.

Abstract: Computer-implemented method for allocating columns of a table stored in a database system into at least two sets of columns, a first set and a second set, the data of the columns allocated to the first set being stored on a primary storage medium using a column-oriented data structure and the data of columns allocated to the second set being stored on a secondary storage medium using a row-oriented data structure, wherein the method comprises the step of allocating the columns of the table to the first and the second set autonomously on the basis of a performance-cost model.

Abstract: The inventors have implemented in a columnar in-memory database and studied access patterns of a large production enterprise system. To obtain accurate cost estimates for a configuration, the inventors have used the what-if capabilities of modern query optimizers. What-if calls, however, are the major bottleneck for most index selection approaches. Hence, a major constraint is to limit the number of what-if optimizer calls. And even though the inventive approach does not limit the index candidate set, it decreases the number of what-if calls because in each iteration step the number of possible (index) extensions is comparably small which results in a limited number of what-if calls.

Abstract: Computer-implemented method for allocating columns of a table stored in a database system into at least two sets of columns, a first set and a second set, the data of the columns allocated to the first set being stored on a primary storage medium using a column-oriented data structure and the data of columns allocated to the second set being stored on a secondary storage medium using a row-oriented data structure, wherein the method comprises the step of allocating the columns of the table to the first and the second set autonomously on the basis of a performance-cost model.

Abstract: A coke-oven door assembly has a rigid door, a mounting block adjacent the door, a door-plug backing plate fixed to the mounting block, and a membrane having a center portion between the backing and mounting blocks and a periphery juxtaposed with a coke-oven door jamb. A blade-type seal is carried on the periphery and engageable with the door jamb and spring units on the door press the seal against the door jamb. A plurality of bolts threaded into the mounting block extend generally perpendicularly outward from the membrane and are each formed with an abutment shoulder directed outward away from the membrane. A plurality of sleeves threaded into the door slidably receive the bolts and are each formed with an abutment shoulder directed inward toward and engageable with the respective bolt abutment so that the mounting block can move perpendicular to the membrane relative to the door with separation of each bolt abutment from the respective sleeve abutment.

Abstract: A leveling door for sealing a leveling opening of a coke oven door has a leveling door body, a diaphragm sheet mounted on the leveling door body at its side facing a leveling opening so as to cover the leveling opening, the diaphragm sheet having an edge and being provided on the edge with a circumferential sealing frame, a plurality of pressing elements acting on the sealing frame and distributed over a periphery of the sealing frame, a plurality of socket pins mounting the pressing element on the leveling door body, and an exchangeable heat protective screen arranged in front of the diaphragm sheet at a side facing the leveling opening.

Abstract: The coke oven door is provided with a sealing diaphragm which has a sealing strip which comes to engagement with the frame which defines the chamber of the coke oven when the door closes, a plurality of pressure elements each including a housing and an adjustable spring to apply a force to the sealing strip to tightly seal the door in the closed position. The door has a number of radial projections that have cast bores, receiving threaded bolts extending through a common cross-piece to which the housing of the pressure elements are also secured. Counter nuts are mounted on the threaded bolts to adjustably secure the position of the cross-piece and thus the housings of the pressure elements secured thereto, and thereby adjust the force applied by the spring to the sealing strip.

Abstract: A door structure for coke oven is disclosed which includes at least two locking head rails and having a door body which is continuously made of a flexible and elastic material. According to this invention, the material of the door body and the sealing membrane or its compression elements are dimensioned such that ratio of the rigidity of the door body to the specific contact pressure of the sealing membrane is so small that the thermal deformation of the body is compensated mainly by the combined locking forces exerted by the head rails and by the contact forces exerted by the sealing strip.