Join operation processing system in distributed data base management system

• US 4,811,207 A
• Filed: 03/06/1986
• Issued: 03/07/1989
• Est. Priority Date: 03/12/1985
• Status: Expired due to Term

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Kawakami, Suguru, Hikita, Sakayuki, Haniuda, Hiromi, Yamamoto, Hideki, Sakamoto, Akifumi
• Primary Examiner(s): Shaw, Gareth D.
• Assistant Examiner(s): Kriess, Kevin A.
• Application Number:
  US06/837,283
• Time in Patent Office: 1,097 Days
• Field of Search: 364/200 MS File, 364/900 MS File, 364/300
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2456 Join operations
• CPC Class Codes: G06F 16/2471 Distributed queries
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99939 Privileged access

Abstract

A join operation processing system and a method of operating the system is usable in a distributed database management system including multiple local database management systems, computers employing distributed databases stored in the local database management systems, and a communication network for connecting said local database management systems and the computers. The join operation processing system can perform a join operation on a relational database. Each of the computers instructs prior computer to performing the join operation, and the database management system, managing relations associated with the join operation to read definitions so as to define said relations, reads the read definitions to thereby determine a process to process the join operation, and issues a request to the prescribed database management system to perform join operation processing based on the determination. Each database management system transfers a local processing result and a local processing request among the database management systems and performs the join operation processing in a pipe line processing sequence.

Claims

1. A method of operating a join operation processing system in a distributed database management system including multiple sites each having a memory and computers each employing a distributed database stored in said memory, said multiple sites and computers being interconnected via a communication network, said method comprising the steps of:

(a) determining whether a processing request from one of the computers is a request to define relations or a request to perform a join operation;

(b) transmitting the request to define the relations to each of the sites if said processing request is a request to define the relations, and transmitting a request to read relation definition to each of the sites if said processing request is a request to perform the join operation;

(c) analyzing the request at each of said sites, for determining whether said request is a request to define the relation or a request to read the relation definition,, and storing the definition in said memory if said request is a request to define the relation, and reading said definition previously stored in the memory and transferring it to the computer if said request is a request to read the relation definition;

(d) determining, upon receiving the relation definitions from each of the sites, a process to perform said join operation in accordance with said request for the join operation, and transmitting a local processing request to a predetermined site;

(e) performing at each of said sites receiving said local processing request a local join operation of the relation managed by the site itself, and transmitting to the next site, if there is processing to be done on the next site, a request for the next site to perform local processing and the result of said local join operation and, if there is no processing to be done on the next site, transmitting the result of the join operation processing effected in the site itself to said computer, so as to thereby effect a join operation between said computer and each site in a pipe line processing sequence based on said steps.

2. A method of operating a join operation processing system according to claim 1, wherein said request to define the relations described in step (a) is created prior to the request for performing the join operation.

3. A join operation processing sysem in a distributed database management system including a plurality of sites each having a memory and computers each for employing a distributed database stored in said memories, said sites and computers being interconnected via a communication network;

wherein each of said computers comprises;

(a) a processing request analysis and execution means for analyzing a processing request on said distributed database from the application program running on the computer, and for determining whether said processing request is a request to define the relations or the processing request for the join operation, and for transmitting, if said processing request is a request to define the relations, said defining request to each site, and, if said processing request is a request to perform the join operation, transmitting a request to read the relation definition to each site, and

(b) a process determination and management means for determining a process to perform join operation based on the relation definition returned from each site and for transmitting local join operation requests to a predetermined site in accordance with said process;

and wherein each of said sites comprises;

(c) a processing request analysis and execution means for analyzing whether the received processing request is a relation defining request from the computer, or a processing request to perform said local join operation, or a request to read the relation definition from the computer, or a request to perform the join operation from said site, and

(d) a database manager means for defining a relation managed by a site itself and for storing the relation definition in said memory if said received processing request is a relation defining request, and reading said relation definition previously stored in said memory and transferring the read result to the computer if said received processing request is a request to read the relation definition, and for receiving, if said received processing request is a request to perform the join operation from said site, a processed result in other site in succession to said join operation processing request, and for performing the join operation processing on said processed result and on the relation managed by the site itself, and for transmitting, said join operation processing rsult to said computer if there is no processing to be done in the next site, and transmitting a processing request to a site other than the next site and the processed result in the site itself if there is any processing to be done at a site other than the next site, so as to thereby effect a join operation between the computer and each site in a pipe line processing sequence.

4. A join operation processing system in a distributed database management system including multiple sites each having a memory, and computers each employing a distributed database stored in said memories, said multiple sites and computers being interconnected via a communication network;

wherein each of said computers comprises;

a processing request analysis and execution means for analyzing a request to process the distributed database, and a process determination and management means for transmitting, if said processing request is a request to process a join operation, a request to read a definition to each site, and for determining a process for the join operation based on the definition transmitted from each site, and for transmitting the processing request based on said process to a predetermined site, and a DBMS access manager for receiving the processed result from the site and transmitting said processed result to the site issuing said processing request;

and wherein each of said sites comprises;

a database processing execution control for reading the definition previously stored in the database and for transmitting the read result to said computer if said received processing request is a request to read the definition from said computer, and a database manager for retrieving the database and for transmitting the retrieved result and a processing result to be done on the next site if said received processing request is a request to perform the join operation from said computer, a second database manager for processing the retrieved result or the retrieved result from the previous site and relations in the database in the present site itself if the received processing request is a processing request from the previous site, and for transmitting the processed result to said computer if there is no processing to be done by the next site, and for transmitting the processed result and a request for processing to be done on the next site if there is any processing to be done in the next site, whereby said join operation processing is performed between said sites and said computers in a pipe line processing sequence.