| General question on dbms_stats [message #616274] |
Sat, 14 June 2014 08:00  |
 |
kiranrathodkr916
Messages: 36
Registered: March 2014
Location: India
|
Member |
|
|
General question on dbms_stats and auto sample size?
what is the impact of having IOTs with overflows and you switch to auto_sample_size and enable approximate NDV .
How does it impact?
|
|
|
|
|
|
| Re: General question on dbms_stats [message #616277 is a reply to message #616274] |
Sat, 14 June 2014 10:43  |
Lalit Kumar B
Messages: 3174
Registered: May 2013
Location: World Wide on the Web
|
Senior Member |
|
|
kiranrathodkr916 wrote on Sat, 14 June 2014 18:30
what is the impact of having IOTs with overflows and you switch to auto_sample_size and enable approximate NDV .
Yes, there have had been several discussions on this and conclusion was :
A quote from J.Lewis Quote:
if you've got IOTs with overflows and you switch to auto_sample_size and enable approximate NDV then the time taken to gather stats on those IOTs may (depending to a large extent on the data clustering) take much longer than it used to.
For more information look at this link http://jonathanlewis.wordpress.com/2014/03/02/auto-sample-size/
|
|
|
|
] 
Blog
Search
Help
Members
Register
Login
Home
