Abstract: Technologies are described for facilitating transaction processing within a database environment. A commit protocol provides for the atomic commit or rollback of a transaction that includes an operation that modifies a metadata entity of the database system and one or more other operations that modify metadata entities or data records of the database system. Innovations are provided for detecting and resolving deadlocks that may arise during transaction processing. Innovations are also provided for providing versioning of metadata entities, including invalidating metadata entities cached at a slave node during the commit at a master node of a transaction that creates a new version of the metadata entity.

Abstract: Systems and methods for generating a metadata log in a database recovery system include generating, at its primary system, a metadata log for a logging period. A change applied to a metadata object accessible from the primary system is detected, and upon detection, the system identifies a pair of a unique metadata identifier and a metadata type for the changed metadata object and determines a metadata structure of the changed metadata object. A data exchange object for the metadata structure is generated and a data exchange element from the data exchange object is created. The metadata log is updated with log information that includes the data exchange element and the pair, which is associated with the data exchange element. Upon the logging period ending, the metadata log is transmitted to a secondary system of the database recovery system for replaying. Related apparatus, systems, techniques and articles are also described.

Abstract: The object of this invention is to provide a combustion device for cooking gas burners. In the combustion device, a frusto-conical flame guide cover (30) having an inclined side surface (31) is seated at the center of the inside area (11) of an annular-shaped bumer head (10). In such a case, the nozzle tips (20) are inclinedly arranged on the bumer head (10) such that the axes of the mixed gas outlets (24) of the tips (20) are converged at a predetermined height of the central axis (32) of the flame guide cover (30). The combustion device of this invention effectively uses low pressure and low price gases such as LNG and quickly generates high temperature heat expected from the conventional middle pressure or high pressure gas burners.