Database management method, database management system, and processing program therefor

Abstract

A method of increasing a processing performance by setting a suitable upper limit of a resources count for each processing request according to an arrangement of hardware such as a storage device or to contents of the processing request. A processing request acceptor accepts the processing request as a data query. An auxiliary storage device forms a storage area where a database is stored. A data operation executor analyzes the accepted processing request and executed the data operations on the basis of the analyzed result. A resource manager manages the respective data operations allocated to generated processes or threads. A buffer manager caches data of the data operations upon execution of the data operations from the auxiliary storage device to a memory, and determines whether or not the data as the target of the data operations are present in the cache.

1 . A database management method in a database management system comprising auxiliary storage devices having a storage area for storing a database therein, the method comprising the steps of:
 holding, by a storage unit, schema definition information including information about a table structure of the database and storage arrangement information including a mapping with a storage area for storing data in the database, and holding an upper limit of a threads count by correlating with the storage devices;   accepting, by a processing request acceptor, a processing request as a data query;   analyzing, by a data operation executor, the accepted processing request, referring the schema definition information and the storage arrangement information, obtaining a data in the database accessed in accordance with the processing request by accessing the plurality of storage devices which store the data in the database, and executing data operations for a plurality of obtained data on the basis of the analyzed result;   managing, by a resource manager, the respective data operations allocated to generated threads for each processing request; and   obtaining, by an each-processing-request each-request resources-count determiner, the upper limit of the threads count correlated with the respective storage devices accessed in accordance with the processing request, calculating the obtained upper limit of the threads count, and determining an upper limit of the threads count for the each processing request.   
     
     
         2 . A database management method according to  claim 1 , wherein the each-processing-request resources count determiner refers to the threads count used by the processing request for each operation of the accepted processing request from performance statistical information about the database management system acquired upon execution of past processing requests, and calculates an upper limit value of the threads count to be used. 
     
     
         3 . A database management method according to  claim 1 , wherein the each-processing-request resources count determiner determines an upper limit value of the threads count used for the each processing request when an execution on the basis of the threads count calculated from an I/O performance of the storage device accessed in accordance with the processing request when an execution. 
     
     
         4 . A database management system comprising auxiliary storage devices having a storage area for storing a database therein, the system comprising:
 a storage unit which holds schema definition information including information about a table structure of the database and storage arrangement information including mapping with a storage area for storing data in the database, and holds an upper limit of a threads count by correlating with the storage devices;   a processing request acceptor configured to accept a processing request as a data query;   a data operation executor configured to analyze the accepted processing request, refer the schema definition information and the storage arrangement information, obtain a data in the database accessed in accordance with the processing request by accessing the plurality of storage devices which store the data in the database, and execute data operations for a plurality of obtained data on the basis of the analyzed result;   a resource manager configured to manage the respective data operations allocated to generated threads for each processing request; and   an each-processing-request each-request resources-count determiner configured to obtain the upper limit of the threads count correlated with the respective storage devices accessed in accordance with the processing request, calculate the obtained upper limit of the threads count, and determine an upper limit of the threads count for the each processing request.   
     
     
         5 . A database management system according to  claim 1 , wherein the each-processing-request resources count determiner is configured to refer to the threads count used by the processing request for each operation of the accepted processing request from performance statistical information about the database management system acquired upon execution of past processing requests, and calculate an upper limit value of the threads count to be used. 
     
     
         6 . A database management system according to  claim 1 , wherein the each-processing-request resources count determiner is configured to determine an upper limit value of the threads count used for the each processing request when an execution on the basis of the threads count calculated from an I/O performance of the storage device accessed in accordance with the processing request when an execution. 
     
     
         7 . A non-transitory computer readable storage medium storing a database management program in a database management system comprising auxiliary storage devices having a storage area for storing a database therein, the database management program executes the steps of:
 holding, by a storage unit, schema definition information including information about a table structure of the database and storage arrangement information including mapping with a storage area for storing data in the database, and holding an upper limit of a threads count by correlating with the storage devices;   accepting, by a processing request acceptor, a processing request as a data query;   analyzing, by a data operation executor, the accepted processing request, referring the schema definition information and the storage arrangement information, obtaining a data in the database accessed in accordance with the processing request by accessing the plurality of storage devices which store the data in the database, and executing data operations for a plurality of obtained data on the basis of the analyzed result;   managing, by a resource manager, the respective data operations allocated to generated threads for each processing request; and   obtaining, by an each-processing-request each-request resources-count determiner, the upper limit of the threads count correlated with the respective storage devices accessed in accordance with the processing request, calculating the obtained upper limit of the threads count, and determining an upper limit of the threads count for the each processing request.   
     
     
         8 . A non-transitory computer readable storage medium storing a database management program according to  claim 1 , wherein the each-processing-request resources count determiner refers to the threads count used by the processing request for each operation of the accepted processing request from performance statistical information about the database management system acquired upon execution of past processing requests, and calculates an upper limit value of the threads count to be used. 
     
     
         9 . A non-transitory computer readable storage medium storing a database management program according to  claim 1 , wherein the each-processing-request resources count determiner determines an upper limit value of the threads count used for the each processing request when an execution on the basis of the threads count calculated from an I/O performance of the storage device accessed in accordance with the processing request when an execution.