WARNING: Computing exact confidence limits for this problem may require much time and memory. Press the system interrupt key to terminate exact computations.
could you please suggest how to overcome this warning.
The warning appears to let you know that exact tests can be time consuming for large tables. Instead of an exact test, you can use a Monte Carlo approximation to the exact test by using the MC option. For an example and discussion, see the article "Monte Carlo simulation for contingency tables in SAS."
ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.