Prefetch parameters with Oracle
Prefetch parameters allow an application to automatically fetch rows from the Oracle® database when opening a cursor.
Before version 2.00, the default prefetch parameters are 50 rows and 65535 bytes for the prefetch buffer. Some customers experienced a huge memory usage with those default values, when using a lot of cursors: It appears that the Oracle client is allocating a buffer of prefetch.memory (64 Kbytes) for each cursor.
Starting with version 2.00, the default is 10 rows and 0 (zero) bytes for the prefetch buffer (memory), meaning that memory is not included in computing the number of rows to prefetch.