Spotlight on Oracle 11.0 - Getting Started Guide

Array Fetch Size Alarm

Oracle client libraries support the ability to retrieve multiple rows from the database in a single operation. When more than one row is retrieved in a single SELECT, the amount of network traffic associated with SELECT operations is radically reduced and typically results in savings of up to 90% in elapsed time.

The Array Fetch Size alarm is raised when the array fetch size used by applications that access the database may be too low — an array fetch size lower than 20 may not be effective.

Addressing this issue usually requires a change in application code.

• In PL/SQL, you may need to use the BULK COLLECT facililty.
• In Java, you may need to use the setFetchSize() method.