How to use the METHOD_OPT parameter in DBMS_STATS.gather_table_stats

Question

Hi there I was just wondering what would be the difference between these 2 METHOD_OPT parameter settings:

FOR COLUMNS SIZE 5 some_column

and

FOR COLUMNS some_column SIZE 5

both will create a histogram with 5 buckets for the column 'some_column' right?

The official Oracle reference states that METHOD_OPT should have this form:

FOR COLUMNS [size clause] column|attribute [size_clause] [,column|attribute [size_clause]...]

but this doesn't really help my case.

I've seen sources which use both versions so not sure if there is any difference.

EDIT

I was told that both of these are the exact same, but then what about these 2:

FOR COLUMNS SIZE 5 some_column SIZE 6 some_column2

and

FOR COLUMNS some_column SIZE 5 some_column2 SIZE 6

Answer 1

Looking at the syntax I would expect that COLUMS size_clause is a global setting, that can be overridden by specific size_clause for a single column. So in case of FOR COLUMNS SIZE 5 col1 SIZE 6, col2 means SIZE 6 takes precedence for col1, but col2 falls back to the default SIZE 5. This is what I would certainly expect, but I haven't verified this experimentally.