For tables that already contain data, use optdiag to display statistics for the table. The “Data row size” shows the average data row length, including the row overhead. This sample optdiag output for the titles table shows 12 forwarded rows and an average data row size of 184 bytes:
Statistics for table: "titles" Data page count: 655 Empty data page count: 5 Data row count: 4959.000000000 Forwarded row count: 12.000000000 Deleted row count: 84.000000000 Data page CR count: 0.000000000 OAM + allocation page count: 6 Pages in allocation extent: 1 Data row size: 184.000000000
You can also use optdiag to check the number of forwarded rows for a table to determine whether your setting for exp_row_size is reducing the number of forwarded rows generated by your applications.
For more information on optdiag, see Chapter 6, “Statistics Tables and Displaying Statistics with optdiag.” in the Performance and Tuning: Monitoring and Analyzing for Performance.