Hello All,
Can anybody throw some light on this problem...
In SQL Server version 7, running on NT 4, the following query (generated by
Business Objects, not me!) can be successfully executed in query analyser
and returns correct results without heavily utilising tembdb. A seek is
performed, based on date, on a clustered index only returning the rows from
Sales_Details_Extract (fact table) that are required:
SELECT
sum(Sales_Enquiry.dbo.Sales_Details_Extract.Value) ,
(CASE WHEN
(
Sales_Enquiry.dbo.Time_v.Month )=( (SELECT Current_Month FROM
BusObj_Control) )
THEN (
sum(Sales_Enquiry.dbo.Sales_Details_Extract.Value)
)
ELSE 0 END),
(CASE WHEN
(
Sales_Enquiry.dbo.Time_v.Month )=( (SELECT Current_Month FROM
BusObj_Control) )
THEN (
sum(Sales_Enquiry.dbo.Sales_Details_Extract.Quanti ty)
)
ELSE 0 END),
Sales_Enquiry.dbo.Time_v.Year,
Sales_Enquiry.dbo.Time_v.Month,
dbo.SCFlattened.SCSubT2Desc
FROM
Sales_Enquiry.dbo.Sales_Details_Extract,
dbo.Title_Hierarchy,
dbo.Customers,
dbo.SCFlattened,
Sales_Enquiry.dbo.Time_v
WHERE
( Sales_Enquiry.dbo.Sales_Details_Extract.ISBN=dbo.T itle_Hierarchy.ISBN and
Sales_Enquiry.dbo.Sales_Details_Extract.Source_Sys tem=dbo.Title_Hierarchy.So
urce_System )
AND (
Sales_Enquiry.dbo.Sales_Details_Extract.Customer=d bo.Customers.Customer )
AND ( Sales_Enquiry.dbo.Sales_Details_Extract.Date between
Sales_Enquiry.dbo.Time_v.Period_Start and
Sales_Enquiry.dbo.Time_v.Period_End )
AND ( dbo.Customers.Sales_Channel=dbo.SCFlattened.SCSubT 6 )
AND (
( (
Sales_Enquiry.dbo.Time_v.Year ) = ( (select Current_Year from
BusObj_Control) ) )
AND Sales_Enquiry.dbo.Sales_Details_Extract.Sale_Type IN (' ', 'S',
'U')
AND Sales_Enquiry.dbo.Sales_Details_Extract.Sale_Categ ory NOT IN ('V',
'R')
AND
dbo.Customers.Customer NOT IN ('61384 ', '68812 ', '61383 ')
AND
dbo.Title_Hierarchy.ISBN NOT IN ('0141014075')
)
GROUP BY
Sales_Enquiry.dbo.Time_v.Year, Sales_Enquiry.dbo.Time_v.Month,
dbo.SCFlattened.SCSubT2Desc
The table sizes are as follows:
Sales_Details_Extract (view containing ~ 70 million rows)
Title_Hierarchy (Table containing ~180k rows)
Customers, (Table containing ~60k rows)
SCFlattened (Table containing ~30k rows)
Time_v (view containing ~ 80 rows)
Total DB Size ~ 33GB
On new hardware running Windows 2003 Server and SQL Server 2000 Enterprise
Ed. The same query causes tempdb to fill (56GB) before we run out of disk
resource. The database is a direct copy i.e. db detached and attached. The
indexes have recently been rebuilt and the 'auto update stats' option is
selected. The query plan seems to indicate a scan of the entire
Sales_Details (70 million rows) is taking place, and suspect a Cartesian
product is the cause of tempdb growing so large.
We've tried unsuccessfully placing the database including tempdb into 'SQL 7
Compatibility Mode'
Any Suggestions would be gratefully received. I have copies of the
execution plans if interested.
Regards,
Ian (ichinds@.hotmail.com)
Have you tried using query hints to influence the plan? "query hints" in
books online has some description.
If you want to try the compatibility mode, then it should be set on your
database, not tempdb.
Wei Xiao [MSFT]
SQL Server Storage Engine Development
http://weblogs.asp.net/weix
This posting is provided "AS IS" with no warranties, and confers no rights.
"Ian" <ian.hinds@.pearsontc.co.uk> wrote in message
news:O%23r3sSX0EHA.3908@.TK2MSFTNGP12.phx.gbl...
> Hello All,
>
> Can anybody throw some light on this problem...
>
> In SQL Server version 7, running on NT 4, the following query (generated
> by
> Business Objects, not me!) can be successfully executed in query analyser
> and returns correct results without heavily utilising tembdb. A seek is
> performed, based on date, on a clustered index only returning the rows
> from
> Sales_Details_Extract (fact table) that are required:
>
> SELECT
> sum(Sales_Enquiry.dbo.Sales_Details_Extract.Value) ,
> (CASE WHEN
> (
> Sales_Enquiry.dbo.Time_v.Month )=( (SELECT Current_Month FROM
> BusObj_Control) )
> THEN (
> sum(Sales_Enquiry.dbo.Sales_Details_Extract.Value)
> )
> ELSE 0 END),
> (CASE WHEN
> (
> Sales_Enquiry.dbo.Time_v.Month )=( (SELECT Current_Month FROM
> BusObj_Control) )
> THEN (
> sum(Sales_Enquiry.dbo.Sales_Details_Extract.Quanti ty)
> )
> ELSE 0 END),
> Sales_Enquiry.dbo.Time_v.Year,
> Sales_Enquiry.dbo.Time_v.Month,
> dbo.SCFlattened.SCSubT2Desc
> FROM
> Sales_Enquiry.dbo.Sales_Details_Extract,
> dbo.Title_Hierarchy,
> dbo.Customers,
> dbo.SCFlattened,
> Sales_Enquiry.dbo.Time_v
> WHERE
> ( Sales_Enquiry.dbo.Sales_Details_Extract.ISBN=dbo.T itle_Hierarchy.ISBN
> and
> Sales_Enquiry.dbo.Sales_Details_Extract.Source_Sys tem=dbo.Title_Hierarchy.So
> urce_System )
> AND (
> Sales_Enquiry.dbo.Sales_Details_Extract.Customer=d bo.Customers.Customer )
> AND ( Sales_Enquiry.dbo.Sales_Details_Extract.Date between
> Sales_Enquiry.dbo.Time_v.Period_Start and
> Sales_Enquiry.dbo.Time_v.Period_End )
> AND ( dbo.Customers.Sales_Channel=dbo.SCFlattened.SCSubT 6 )
> AND (
> ( (
> Sales_Enquiry.dbo.Time_v.Year ) = ( (select Current_Year from
> BusObj_Control) ) )
> AND Sales_Enquiry.dbo.Sales_Details_Extract.Sale_Type IN (' ', 'S',
> 'U')
> AND Sales_Enquiry.dbo.Sales_Details_Extract.Sale_Categ ory NOT IN ('V',
> 'R')
> AND
> dbo.Customers.Customer NOT IN ('61384 ', '68812 ', '61383 ')
> AND
> dbo.Title_Hierarchy.ISBN NOT IN ('0141014075')
> )
> GROUP BY
> Sales_Enquiry.dbo.Time_v.Year, Sales_Enquiry.dbo.Time_v.Month,
> dbo.SCFlattened.SCSubT2Desc
>
>
> The table sizes are as follows:
>
> Sales_Details_Extract (view containing ~ 70 million rows)
> Title_Hierarchy (Table containing ~180k rows)
> Customers, (Table containing ~60k rows)
> SCFlattened (Table containing ~30k rows)
> Time_v (view containing ~ 80 rows)
>
> Total DB Size ~ 33GB
>
>
> On new hardware running Windows 2003 Server and SQL Server 2000 Enterprise
> Ed. The same query causes tempdb to fill (56GB) before we run out of disk
> resource. The database is a direct copy i.e. db detached and attached.
> The
> indexes have recently been rebuilt and the 'auto update stats' option is
> selected. The query plan seems to indicate a scan of the entire
> Sales_Details (70 million rows) is taking place, and suspect a Cartesian
> product is the cause of tempdb growing so large.
>
> We've tried unsuccessfully placing the database including tempdb into 'SQL
> 7
> Compatibility Mode'
>
> Any Suggestions would be gratefully received. I have copies of the
> execution plans if interested.
>
> Regards,
>
> Ian (ichinds@.hotmail.com)
>
>
>
>
|||Ian,
I don't know how much influence you have over the query or the schema. I
assume you cannot change the query.
First of all, make sure you statistics are up to date. Run UPDATE
STATISTICS when in doubt.
Next, you could check if all join keys are of the same data type. For
example, column Time_v.Year should have the exact same data type (for
optimal performance) as BusObj_Control.Current_Year.
Also check if the columns in the WHERE clause have the same data type as
the literals of the expressions. For example, column Customers.Customer
should be char or varchar in order to match the data type of the literal
'61384 '.
Hope this helps,
Gert-Jan
Ian wrote:
> Hello All,
> Can anybody throw some light on this problem...
> In SQL Server version 7, running on NT 4, the following query (generated by
> Business Objects, not me!) can be successfully executed in query analyser
> and returns correct results without heavily utilising tembdb. A seek is
> performed, based on date, on a clustered index only returning the rows from
> Sales_Details_Extract (fact table) that are required:
> SELECT
> sum(Sales_Enquiry.dbo.Sales_Details_Extract.Value) ,
> (CASE WHEN
> (
> Sales_Enquiry.dbo.Time_v.Month )=( (SELECT Current_Month FROM
> BusObj_Control) )
> THEN (
> sum(Sales_Enquiry.dbo.Sales_Details_Extract.Value)
> )
> ELSE 0 END),
> (CASE WHEN
> (
> Sales_Enquiry.dbo.Time_v.Month )=( (SELECT Current_Month FROM
> BusObj_Control) )
> THEN (
> sum(Sales_Enquiry.dbo.Sales_Details_Extract.Quanti ty)
> )
> ELSE 0 END),
> Sales_Enquiry.dbo.Time_v.Year,
> Sales_Enquiry.dbo.Time_v.Month,
> dbo.SCFlattened.SCSubT2Desc
> FROM
> Sales_Enquiry.dbo.Sales_Details_Extract,
> dbo.Title_Hierarchy,
> dbo.Customers,
> dbo.SCFlattened,
> Sales_Enquiry.dbo.Time_v
> WHERE
> ( Sales_Enquiry.dbo.Sales_Details_Extract.ISBN=dbo.T itle_Hierarchy.ISBN and
> Sales_Enquiry.dbo.Sales_Details_Extract.Source_Sys tem=dbo.Title_Hierarchy.So
> urce_System )
> AND (
> Sales_Enquiry.dbo.Sales_Details_Extract.Customer=d bo.Customers.Customer )
> AND ( Sales_Enquiry.dbo.Sales_Details_Extract.Date between
> Sales_Enquiry.dbo.Time_v.Period_Start and
> Sales_Enquiry.dbo.Time_v.Period_End )
> AND ( dbo.Customers.Sales_Channel=dbo.SCFlattened.SCSubT 6 )
> AND (
> ( (
> Sales_Enquiry.dbo.Time_v.Year ) = ( (select Current_Year from
> BusObj_Control) ) )
> AND Sales_Enquiry.dbo.Sales_Details_Extract.Sale_Type IN (' ', 'S',
> 'U')
> AND Sales_Enquiry.dbo.Sales_Details_Extract.Sale_Categ ory NOT IN ('V',
> 'R')
> AND
> dbo.Customers.Customer NOT IN ('61384 ', '68812 ', '61383 ')
> AND
> dbo.Title_Hierarchy.ISBN NOT IN ('0141014075')
> )
> GROUP BY
> Sales_Enquiry.dbo.Time_v.Year, Sales_Enquiry.dbo.Time_v.Month,
> dbo.SCFlattened.SCSubT2Desc
> The table sizes are as follows:
> Sales_Details_Extract (view containing ~ 70 million rows)
> Title_Hierarchy (Table containing ~180k rows)
> Customers, (Table containing ~60k rows)
> SCFlattened (Table containing ~30k rows)
> Time_v (view containing ~ 80 rows)
> Total DB Size ~ 33GB
> On new hardware running Windows 2003 Server and SQL Server 2000 Enterprise
> Ed. The same query causes tempdb to fill (56GB) before we run out of disk
> resource. The database is a direct copy i.e. db detached and attached. The
> indexes have recently been rebuilt and the 'auto update stats' option is
> selected. The query plan seems to indicate a scan of the entire
> Sales_Details (70 million rows) is taking place, and suspect a Cartesian
> product is the cause of tempdb growing so large.
> We've tried unsuccessfully placing the database including tempdb into 'SQL 7
> Compatibility Mode'
> Any Suggestions would be gratefully received. I have copies of the
> execution plans if interested.
> Regards,
> Ian (ichinds@.hotmail.com)
Salil wrote:
