what is diff stats on coln and Index.

Database
Enthusiast

what is diff stats on coln and Index.

Hi All,
What is the differnce between Collecting Stats on a Column and Collecting Stats on Index, which is created on the same coln
eg...
say coln emp_no is having Index on it...Hence, what is the diffence when we are collecting statistics on coln emp_no and collecting statistics on Index of emp_no....

Waiting for reply.....

Regards...
2 REPLIES
Enthusiast

Re: what is diff stats on coln and Index.

Hi,

Collecting statistics on a group of columns that are already indexed will only have the statistics of the index .
collect stat statements on the particular column against the same group of
columns, stores only the stats about the particular column only.

if its a grouped index only then u can easily see the diff but if u see for the single column index then you wont find the difference.
both the collect stats on index and column will give the same stats only

Enthusiast

Re: what is diff stats on coln and Index.

Hi

The question you need to ask is whcih column will I be accessing the most and Collect Stats on them. It is alos a very good idea to collect stats on ALL index columns, especially on the UPI NUPI.