Number of Buckets in Histogram?

Hi,

Is there any kind of formulaeic way to appropriately select the number of buckets for a histogram in an ANALYZE statement?

The oracle manual does not provide any insight into this, simply saying to experiment with different values (also stating that a size of 75 is recommended for most data distributions...and I have no idea what that is supposed to mean).

I have a table of 1 million rows and one column in that table has 6 distinct values, skewed. Does this mean I should create a 6 bucket histogram on this column? Is there a relationship between cardinality of the column and the appropriate histogram value?

What about a different column in this table that has 300 distinct values which are skewed. The maximum number of buckets on a histogram is 254. What do I do?

I would love to know if anyone has a mathematical formula or logical algorithm which I can use to determine how many buckets to include in analyze statements.

Thanks,

Gavin

• Posted via NewsOne.Net: Free (anonymous) Usenet News via the Web ----- http://newsone.net/ -- Free reading and anonymous posting to 60,000+ groups NewsOne.Net prohibits users from posting spam. If this or other posts made through NewsOne.Net violate posting guidelines, email abuse_at_newsone.net