Auto create stats on but DTA recommends creating them

So I am running a query against a database that has Auto Create statistics
turned on and then what I did was pass this same query to DTA and it
recommends creating statistics as an improvement. Not to mention, it also
said to create some indices.
So the question I have is, when I did run the query, why does SQL not create
those statistics that DTA was recommending ?
Hi Hassan
Are these statistics on multiple columns?
John
"Hassan" wrote:

> So I am running a query against a database that has Auto Create statistics
> turned on and then what I did was pass this same query to DTA and it
> recommends creating statistics as an improvement. Not to mention, it also
> said to create some indices.
> So the question I have is, when I did run the query, why does SQL not create
> those statistics that DTA was recommending ?
>
|||I wish I had it saved .. Not sure..
Is that a bug where if it is on multiple columns, the auto create stats
doesnt automatically take care of it when i run the query ?
"John Bell" <jbellnewsposts@.hotmail.com> wrote in message
news:E1D0BBFB-4A56-4FA2-9134-609341226144@.microsoft.com...[vbcol=seagreen]
> Hi Hassan
> Are these statistics on multiple columns?
> John
> "Hassan" wrote:
|||No, it is not a bug. John may refer to the fact that statistics on multiple
columns (non-indexed) are not created automatically by SQL Server. You need
to create these statistics manually. But once these multi-columns statistics
are created, SQL Server will automatically update them if Auto Update
Statistics is set to True.
Hope this helps,
Ben Nevarez
Senior Database Administrator
AIG SunAmerica
"Hassan" wrote:

> I wish I had it saved .. Not sure..
> Is that a bug where if it is on multiple columns, the auto create stats
> doesnt automatically take care of it when i run the query ?
> "John Bell" <jbellnewsposts@.hotmail.com> wrote in message
> news:E1D0BBFB-4A56-4FA2-9134-609341226144@.microsoft.com...
>
|||Hi Hassan
Ben has said that the AUTO_CREATE_STATISTICS will only create statistics for
a single column and this is by design.
Unless you have explicitly deleted the DTA session, you should be able to
review the output again if you go back into DTA.
John
"Hassan" wrote:

> I wish I had it saved .. Not sure..
> Is that a bug where if it is on multiple columns, the auto create stats
> doesnt automatically take care of it when i run the query ?
> "John Bell" <jbellnewsposts@.hotmail.com> wrote in message
> news:E1D0BBFB-4A56-4FA2-9134-609341226144@.microsoft.com...
>
sql