5	Designing ODBC Applications for Performance Optimization

Developing performance-oriented ODBC applications is not easy. Microsoft’s ODBC Programmer’s Reference does not provide information about system performance. In addition, ODBC drivers and the ODBC driver manager do not return warnings when applications run inefficiently. This chapter contains some general guidelines that have been compiled by examining the ODBC implementations of numerous shipping ODBC applications. These guidelines include:

■	Use catalog functions appropriately

■	Retrieve only required data

■	Select functions that optimize performance

■	Manage connections and updates

Following these general rules will help you solve some common ODBC performance problems, such as those listed in the following table Table 5-1.

Table 5-1. Common Performance Problems Using ODBC Applications 

Problem	Solution	See guidelines in...
Network communication is slow.	Reduce network traffic.	“Using Catalog Functions”
The process of evaluating complex SQL queries on the database server is slow and can reduce concurrency.	Simplify queries.	“Using Catalog Functions” “Selecting ODBC Functions”
Excessive calls from the application to the driver slow performance.	Optimize application-to-driver interaction.	“Retrieving Data” “Selecting ODBC Functions”
Disk I/O is slow.	Limit disk input/output.	“Managing Connections and Updates”