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A METHOD FOR REDUCING NETWORK COSTS FOR DYNAMIC SWL SELECT STATEMENTS

IP.com Disclosure Number: IPCOM000014103D
Original Publication Date: 2001-Feb-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 1 page(s) / 51K

Publishing Venue

IBM

Abstract

A Method for Reducing Network Costs for Dynamic SQL SELECT Statements Problem Solved by This Invention (Summary) This invention provides a method for minimizing the number of network send/receive operations required to issue dynamic SQL SELECT statements from a client system that is remotely connected to a relational database management system (RDBMS) server. The method minimizes network send/receive operations, without restricting the SQL functions provided by the RDBMS server. Advantage:

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  A METHOD FOR REDUCING NETWORK COSTS FOR DYNAMIC SWL SELECT STATEMENTS

A Method for Reducing Network Costs for Dynamic SQL SELECT Statements

Problem Solved by This Invention (Summary)

This invention provides a method for minimizing the number of network send/receive operations required to issue dynamic SQL SELECT statements from a client system that is remotely connected to a relational database management system (RDBMS) server. The method minimizes network send/receive operations, without restricting the SQL functions provided by the RDBMS server.

Advantage:

The algorithm allows the client system to recognize when it is appropriate to issue a dynamic SQL SELECT statement with a single network send/receive operation. The algorithm also allows the client system to recognize when at least two network send/receive operations are required to produce the correct result for a dynamic SQL SELECT. Application elapsed time is reduced for dynamic SQL SELECT statements by requiring fewer network send/receive operations between the client and the remote RDBMS server. Fewer CPU cycles are consumed by the client system, due to the reduced number of network send/receive operations. Fewer CPU cycles are consumed by the server system, due to the reduced number of network send/receive operations.

The algorithm consists of the following steps:

When the application program receives a PREPARE or PREPARE INTO request, the client system examines the SQL statement, by

    scanning for the first token in the SQL statement. After folding the token to upper case characters, the client compares the token to the string 'SELECT'. If the comparison matches, the algorithm coninues to step 2. If the comparison fails, the SQL statements is not a query, so it is not appropriate to issue PREPARE/DESCRIBE/OPEN for this SQL statement. The client system processes the SQL statement in the same fashion that was used prior to this invention.
2. When the SQL statement is a query, the client builds a message requesting a PREPARE operation. The PREPARE message includes the SQL statement received from the application program. The algorithm continues to step 3.
3. The client adds a DESCRIBE operation to the PREPARE message, so that a separate network message is not required to satisfy DESCRIBE requests that might be received from the application program. This will occasionally cause the server to process a DESCRIBE request that is never issued by the application program, but this cost is minimal compared to issuing a separate network send/receive operation for each SQL DESCRIBE statement. The algorithm continues to step 4.
4. Next, the...