I thought of A and will use C cause nowdays usually we use asm; all storage parameters for tablespaces, tables, indexes are default and not based on block size and avg record size that to because Block size record size or avg record size do not influence recruing cost as bigger capacity storage devices are available at afordable size I think tom kyte has said somewhere after 9i, use bigger capacity decices use asm and leave it to oracle, i think it is applicable to 11g too. On 2 Aug 2011 19:58, "Robert Freeman" <robertgfreeman@xxxxxxxxx> wrote: Without looking in the docs, answer this question: When collecting Oracle statistics in 18.104.22.168 (generally, there are always fringe cases) you should: A. Manually set the sample size and not take the default. B. Use the analyze command. C. Use the default value for the sample size. D. Use a sample size between 10 and 20. E. Set the _optimizer_stats_modify parameter first to a value of 60. What is your answer and why? RF Robert G. Freeman Master Principal Consultant, Oracle Corporation, Oracle ACE Author of various books on RMAN, New Features and this shorter signature line. Blog: http://robertgfreeman.blogspot.com Note: THIS EMAIL IS NOT AN OFFICIAL ORACLE SUPPORT COMMUNICATION. It is just the opinion of one Oracle employee. I can be wrong, have been wrong in the past and will be wrong in the future. If your problem is a critical production problem, you should always contact Oracle support for assistance. Statements in this email in no way represent Oracle Corporation or any subsidiaries and reflect only the opinion of the author of this email.