Automatic statistics on compound index

I just read a note in a book that says that SQL Server 2000 only
automatically updates the statistics on just the first column of a compound
index (provided automatic statistics feature is turned on). It suggests
that the DBA should create statistics on the other columns.
I'd never heard that before, and can't seem to find that little fasinating
tidbit in any other source.
Can anybody confirm that this is true?"Emmet Gray" <egray1@.hot.rr.com> wrote in message
news:uc9EhPDXDHA.2464@.TK2MSFTNGP09.phx.gbl...
> I just read a note in a book that says that SQL Server 2000 only
> automatically updates the statistics on just the first column of a
compound
> index (provided automatic statistics feature is turned on). It suggests
> that the DBA should create statistics on the other columns.
> I'd never heard that before, and can't seem to find that little fasinating
> tidbit in any other source.
> Can anybody confirm that this is true?
>
That's correct - this is a situation where you may want to consider manually
statistics on columns other than the first column of a composite index.
Steve

Automatic index (Statistics) vs Manually created indexes

Hi,
I noticed SQL Server, version 2000 in my case, automatically created indexes
(WA_Sys_... indexes) based on its query optimization functionality.
My question is; would my database performance increase if I created indexes
manually instead of depending on the (correct) created automatic indexes?
Erik
Hi
WA_ are not indexes, but statstics.
A real index is much better than statistics. A statistic is there to help
the query optimiser decide how to process a query, and not used for data
access.
http://www.sql-server-performance.com
Regards
Mike
"Erik Tamminga" wrote:

> Hi,
> I noticed SQL Server, version 2000 in my case, automatically created indexes
> (WA_Sys_... indexes) based on its query optimization functionality.
> My question is; would my database performance increase if I created indexes
> manually instead of depending on the (correct) created automatic indexes?
> Erik
>
>

Automatic index (Statistics) vs Manually created indexes

Hi,
I noticed SQL Server, version 2000 in my case, automatically created indexes
(WA_Sys_... indexes) based on its query optimization functionality.
My question is; would my database performance increase if I created indexes
manually instead of depending on the (correct) created automatic indexes?
ErikHi
WA_ are not indexes, but statstics.
A real index is much better than statistics. A statistic is there to help
the query optimiser decide how to process a query, and not used for data
access.
http://www.sql-server-performance.com
Regards
Mike
"Erik Tamminga" wrote:
> Hi,
> I noticed SQL Server, version 2000 in my case, automatically created indexes
> (WA_Sys_... indexes) based on its query optimization functionality.
> My question is; would my database performance increase if I created indexes
> manually instead of depending on the (correct) created automatic indexes?
> Erik
>
>

Automatic index (Statistics) vs Manually created indexes

Hi,
I noticed SQL Server, version 2000 in my case, automatically created indexes
(WA_Sys_... indexes) based on its query optimization functionality.
My question is; would my database performance increase if I created indexes
manually instead of depending on the (correct) created automatic indexes?
ErikHi
WA_ are not indexes, but statstics.
A real index is much better than statistics. A statistic is there to help
the query optimiser decide how to process a query, and not used for data
access.
http://www.sql-server-performance.com
Regards
Mike
"Erik Tamminga" wrote:

> Hi,
> I noticed SQL Server, version 2000 in my case, automatically created index
es
> (WA_Sys_... indexes) based on its query optimization functionality.
> My question is; would my database performance increase if I created indexe
s
> manually instead of depending on the (correct) created automatic indexes?
> Erik
>
>