摘要:
An execution plan of a query for a parallel database system is determined. In one arrangement, the parallel database system is a relational database management system. The execution plan of the query is determined by an optimizer program. Execution plans are inserted into one or more explain tables that are accessible by a visual explain and compare module to display the steps of the execution plan in a graphical user interface. Parallel execution of steps of the execution plan can be depicted in the graphical user interface. Further, plural execution plans for a given query under different conditions may be displayed for comparison.
摘要:
A closed granular chemical handling system comprising a dispensing valve and a receiving valve. The dispensing valve and the receiving valve are automatically opened when the valves are coupled together, and are automatically closed when the valves are uncoupled from one another. The valves are configured so that the receiving valve always is the first to open and the last to close. The valves are driven together by a camming structure having a neutral portion that acts as a delay between the opening and closing of both valves so as to allow granular material to flow from between the valves through the receiving valve.
摘要:
In a database system, at least one metric associated with resources in a database system used by multiple classes of requests is monitored, where a first of the multiple classes is associated with a lower priority than a second of the multiple classes. A throttle limit is calculated for requests of the first class, based on the monitored metric. The calculated throttle limit is used to determine scheduling of the request of the first class for execution.
摘要:
An optimization technique is provided that optimizes data access by mapping each table, or row and/or column in a table, to a particular query, depending on whether the data in said table, row or column is ‘hot’ or ‘cold’ data. In one aspect, the invention features a method for optimizing the access time of an SQL query to a database including data. The method includes receiving, for each query type, a data frequency access measure and associating each query type with a processing rule set, according to the received data frequency access measure.
摘要:
A filter receives a request to perform an operation in a database system, and the filter receives a resource estimate relating to the request from an optimizer. The filter determines whether the resource estimate exceeds an available resource of the database system, and if so, the filter rejects the request prior to execution of the request.
摘要:
A test system receives environment information of a target database system, where the environment information includes information relating to hardware and software components of the target database system, and one or more of: definitions of workloads in the target database system, and settings of a scheduler in the target database system. The test system emulates an environment of the target database system using the received environment information, and database software is executed in the emulated environment in the test system.
摘要:
A method, computer program, and system are disclosed for executing a utility on a database system having a plurality of database system nodes. Each database system node has an existing load. An increased load on the database system required to execute the utility is determined. The existing load on each of the database system nodes is determined. The increased load is distributed in such a way as to balance the load among the database system nodes.
摘要:
A database system includes an optimizer to generate resource estimates regarding execution of a request in the database system, and a regulator to monitor progress of execution of the request (and in some examples every step of the request), and to adjust the resource estimates based on the monitored progress. The regulator also adjusts a priority setting of the request according to the adjusted resource estimates.
摘要:
Computing capacity of a computing environment can be managed by controlling it associated processing capacity based on a target (or desired) capacity. In addition, fine-grained control over the processing capacity can be exercised. For example, a computing system can change the processing capacity (e.g., processing rate) of at least one processor operating based on a target capacity. The computing system may also be operable to change the processing capacity based on a measured processing capacity (e.g., a measured average of various processing rates of a processor taken over a period of time when a processor may have been operating at different processing rates over that period). By way of example, the processing rate of a processor can be switched between 1/8 and 2/8 of a maximum processing rate to achieve virtually any effective processing rates between them.
摘要:
Capacity of a database system and/or a computing system that includes a database can be effectively changed from a current computing capacity to another computing capacity. This can be achieved by causing usage capacity of at least one of resource to be changed when the database is active. By way of example, capacity of a database system can be regulated by delaying the execution of the database work based on a target capacity. As a result, database work can take relatively longer to complete when the capacity of a database is effectively regulated to be below its full capacity. In effect, a portion of available capacity (excess capacity) can be made inaccessible to the database. However, excess capacity can be used to manage various services of the database in accordance with one or more service criteria (e.g., Service Level Goals or Agreements).