System and method for asynchronous database command processing

• US 5,689,697 A
• Filed: 06/06/1995
• Issued: 11/18/1997
• Est. Priority Date: 06/27/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hidalgo, Domingo Segundo, Williamson, Leigh Allen, Edwards, William Mitchell
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Homere, Jean Raymond
• Application Number:
  US08/469,703
• Time in Patent Office: 896 Days
• Field of Search: 395/603, 395/610, 395/200.03, 395/200.11, 395/604, 395/608, 395/825
• US Class Current: 1/1
• CPC Class Codes: G06F 16/252 between a Database Management System and a front-end application
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

A system and method for asynchronously processing SQL language statements in a database management system. A process assigns a unique database handle to each requested connection between an application program and a database, Each application can be concurrently connected to multiple databases. Databases are alternately activated for synchronous or asynchronous processing using the database handle. Following an asynchronous connection, SQL statements are dispatched for asynchronous processing. The application program dispatches an asynchronous statement, performs other processing and then periodically polls the database system to determine whether the statement has completed processing. SQL statement dispatch for synchronous processing performs like current synchronous SQL language systems by waiting for completion of SQL statement processing before continuing.

Claims

1. A computer implemented method for processing query statements by a database management system, the method comprising the steps of:

accepting a connection request from an application program for connecting said application program to said database management system;

establishing an interprocess connection in response to said connection request, the connection having a unique connection identifier;

testing to determine whether an asynchronous or synchronous connection was requested;

activating the connection for either synchronous or asynchronous processing, based on the results of the testing step;

accepting a query statement for processing on the activated connection; and

when the connection has been activated for asynchronous processing,

responding to periodic polling by the application program to the database management system using the unique connection identifier to indicate whether the dispatched query statement has completed processing;

returning reply data in response to the periodic polling if the dispatched query statement has completed processing; and

returning an incomplete processing indicator otherwise.

2. The method of claim 1, wherein the query statements conform to Structured Query Language (SQL) syntax.

6. A computer program product having a computer readable medium having computer program logic recorded thereon for causing a computer system to asynchronously to process query statements in a database management system, the computer program product comprising:

program product means for causing said computer system to accept from an application program a request to connect to a database in said database management system;

program product means for causing said computer system to establish a connection in response to said request and to return a unique identifier for the connection;

program product means for causing said computer system to test said request to connect to determine whether synchronous or asynchronous processing is requested;

program product means for causing said computer system to activate said connection in a synchronous or an asynchronous mode in response to said program product means for causing said computer system to test;

program product means for causing said computer system to accept a query statement dispatched to said database management system; and

program product means for causing said computer system to respond to periodic polling from said application program to the database management system to determine whether the query statement has completed processing, if said connection is activated in asynchronous mode;

the computer program product of claim 1, further comprising;

program product means for causing said computer system to return data to said application program in response to said periodic polling if said query processing is complete or causing said computer system to return an incomplete processing indicator otherwise.

7. The computer program product of claim 6, further comprising:

program product means for causing said computer system to communicate between said application program and said database management means;

program product means for causing said computer system to create control blocks in said database management system; and

program product means for causing said computer system to assign a unique identifier to the control blocks for uniquely identifying the connection.

8. The system of claim 6, wherein the query statements follow the syntax of are structured query language (SQL) statements.

3. A database management system for processing query statements generated by an application program running on a computer system having memory and at least one processor said database management system running on a computer system having memory and at least one processor, the system comprising:

connection means in said database management system for accepting an application program interprocess connection request to a database and returning a unique connection identifier for the interprocess connection;

means for testing said connection request to determine whether asynchronous or synchronous query processing is requested;

means for activating the connection in an asynchronous mode if said test result indicates asynchronous processing is requested and activating the connection in synchronous mode otherwise;

means for accepting a query statement processing request from said application program to said database management system; and

means for responding to periodic polling from the application program seeking to determine whether the query statement has completed processing;

means for returning data to said application program in response to said periodic polling if the query statement has completed processing;

means for returning an incomplete processing indicator otherwise.

5. The system of claim 3, wherein the query statement processing requests follow the syntax of are structured query language (SQL) statements.

4. The system of claim 4, further comprising:

interprocess communication means for communicating between said application program and said database management means;

control block means in said database management means for storing data associating said application program with said database in said database management system; and

control block identification means for assigning a unique identifier to the control block means for uniquely identifying the connection.