10 The Progress OpenEdge® Wire Protocol Driver : Performance Considerations

Performance Considerations
The following connection options can enhance driver performance. You can also enhance performance through efficient application design. Refer to the DataDirect Connect Series for ODBC Reference for details.
Encryption Method (EncryptionMethod): Data encryption may adversely affect performance because of the additional overhead (mainly CPU usage) that is required to encrypt and decrypt data.
Failover Mode (FailoverMode): Although high availability that replays queries after a failure provides increased levels of protection, it can adversely affect performance because of increased overhead.
Fetch Array Size (ArraySize): Reducing the number of round trips on the network to the approximate number of rows being fetched increases performance. For example, if your application normally fetches 200 rows, it is more efficient for the driver to fetch 200 rows at one time over the network than to fetch 50 rows at a time during four round trips over the network.
NOTE: The ideal setting for your application will vary. To calculate the ideal setting for this option, you must know the size in bytes of the rows that you are fetching and the size in bytes of your Network Packet. Then, you must calculate the number of rows that will fit in your Network Packet, leaving space for packet overhead. For example, suppose your Network Packet size is 1024 bytes and the row size is 8 bytes. Dividing 1024 by 8 equals 128; however, the ideal setting for Fetch Array Size is 127, not 128, because the number of rows times the row size must be slightly smaller than the Network Packet size.