Improve performance of a sql query

Question

I am looking for some tips/tricks to improve performance of a stored procedure with multiple SELECT statements inserting into a table. All objects I am joining on are already indexed.

I believe the reason this stored procedure takes almost an hour to run is because there are multiple SELECT statements using following two views: rvw_FinancialLineItemValues and rvw_FinancialLineItems

Also, each SELECT statement uses specific hard-coded values for AccountNumber, LineItemTypeID, and few other field values coming from two views mentioned above.

Would it improve performance if I create a temporary table, which gets ALL data needed for these SELECT statements at once and then using this temporary table in my join instead?

Are there any other ways to improve performance and manageability?

        SELECT
         @scenarioid,
         @portfolioid,
         pa.Id,
         pa.ExternalID,       
         (select value from fn_split(i.AccountNumber,'.') where id = 1),
         ac.[Description],
         cl.Name,
         NullIf((select value from fn_split(i.AccountNumber,'.') where id = 2),''),
         NullIf((select value from fn_split(i.AccountNumber,'.') where id = 3),''),
         ty.Name,
         v.[Date],
         cast(SUM(v.Amount) as decimal(13,2)),
         GETDATE()

    FROM rvw_FinancialLineItems i
    INNER JOIN rvw_Scenarios sc
        ON i.ScenarioId = sc.Id
        AND sc.Id = @scenarioid
        AND sc.PortfolioId = @portfolioid
    INNER JOIN #pa AS pa
        ON i.PropertyAssetID = pa.Id
    INNER JOIN rvw_FinancialLineItemValues v
        ON i.ScenarioId = v.ScenarioId
        AND i.PropertyAssetID = v.PropertyAssetID
        AND i.Id = v.FinancialLineItemId
        AND ((i.BusinessEntityTypeId = 11
        AND i.LineItemTypeId = 3002)
        OR (i.LineItemTypeId IN (2005, 2010, 2003, 2125, 2209, 5012, 6001)
        AND i.ModeledEntityKey = 1))
        AND i.AccountNumber not in ('401ZZ','403ZZ')
  AND i.AccountNumber not in ('401XX')
        AND i.AccountNumber not in ('40310','41110','42010','41510','40190','40110')  -- exclude lease-level revenues selected below
        AND v.[Date] BETWEEN @fromdate AND 
          CASE
            WHEN pa.AnalysisEnd < @todate THEN pa.AnalysisEnd
            ELSE @todate
          END
        AND v.ResultSet IN (0, 4)
    INNER JOIN rvw_Portfolios po
        ON po.Id = @portfolioid
    INNER JOIN Accounts ac
        ON po.ChartOfAccountId = ac.ChartOfAccountId
        AND i.AccountNumber = ac.AccountNumber
        AND ac.HasSubAccounts = 0
    INNER JOIN fn_LookupClassTypes() cl
        ON ac.ClassTypeId = cl.Id
    INNER JOIN LineItemTypes ty
        ON ac.LineItemTypeId = ty.Id
    LEFT JOIN OtherRevenues r
        ON i.PropertyAssetID = r.PropertyAssetID
        AND i.AccountNumber = r.AccountID
        AND v.[Date] BETWEEN r.[Begin] AND r.[End]
    WHERE (r.IsMemo IS NULL
    OR r.IsMemo = 0)
    GROUP BY    pa.AnalysisBegin
                ,pa.Id
                ,pa.ExternalID
                ,i.AccountNumber
                ,ac.[Description]
                ,cl.Name
                ,ty.Name
                ,v.[Date]
    HAVING SUM(v.amount) <> 0

Answer 1

You should run your query with SET SHOWPLAN ALL ON or with Management Studio Save Execution Plan and look for inefficiencies.

There are some resources online that help in analyzing the results, such as: http://www.sqlservercentral.com/articles/books/65831/

See also How do I obtain a Query Execution Plan?

Answer 2

I would look to the following first. What are the wait types relevant to your stored procedure here? Are you seeing a lot of disk io time? Are things being done in memory? Maybe there's network latency pulling that much information.

Next, what does the plan look like for the procedure, where does it show all the work is being done?

The views definitely could be an issue as you mentioned. You could maybe have pre-processed tables so you don't have to do as many joins. Specifically the joins where you are seeing the most amount of CPU spent.

Answer 3

Correlated subqueries are generally slow and should never be used when you are trying for performance. Use the fn_split to create a temp table Index it if need be and then join to it to get the value you need. You might need to join multiple times for different value, without actually knowing the data I am having a hard time visualizing.

It is also not good for performance to use OR. Use UNION ALL in a derived table instead.

Since you have all those conditions on the view rvw_FinancialLineItems, yes it might work to pull those out to a temp table and then index the temp table.

YOu might also see if using the views is even a good idea. Often views have joins to many table that you aren't getting data from and thus are less performant than querying only the tables you actually need. This is especially true if your organization was dumb enough to make views that call views.

Answer 4

First thing, which fn_split() UDF are you using? If you are not using the table-Valued inline UDF, then this is notoriously slow.

Second, is the UDF fn_LookupClassTypes() an inline table valued UDF? If not, convert it to an inline Table-Valued UDF.

Last, your SQL query had some redundancies. Try this and see what it does.

SELECT @scenarioid, @portfolioid, pa.Id, pa.ExternalID,       
      (select value from fn_split(i.AccountNumber,'.') 
       where id = 1),  ac.[Description], cl.Name,
     NullIf((select value from fn_split(i.AccountNumber,'.') 
             where id = 2),''),
     NullIf((select value from fn_split(i.AccountNumber,'.') 
             where id = 3),''), ty.Name, v.[Date],
     cast(SUM(v.Amount) as decimal(13,2)), GETDATE()

FROM rvw_FinancialLineItems i
   JOIN rvw_Scenarios sc ON sc.Id = i.ScenarioId 
   JOIN #pa AS pa ON pa.Id = i.PropertyAssetID  
   JOIN rvw_FinancialLineItemValues v
      ON v.ScenarioId = i.ScenarioId
        AND v.PropertyAssetID = i.PropertyAssetID
        AND v.FinancialLineItemId = i.Id  
   JOIN rvw_Portfolios po ON po.Id = sc.portfolioid
   JOIN Accounts ac
      ON ac.ChartOfAccountId = po.ChartOfAccountId
         AND ac.AccountNumber = i.AccountNumber
   JOIN fn_LookupClassTypes() cl On cl.Id = ac.ClassTypeId 
   JOIN LineItemTypes ty On ty.Id = ac.LineItemTypeId
   Left JOIN OtherRevenues r
      ON r.PropertyAssetID = i.PropertyAssetID
        AND r.AccountID = i.AccountNumber  
        AND v.[Date] BETWEEN r.[Begin] AND r.[End]

WHERE i.ScenarioId = @scenarioid
   and ac.HasSubAccounts = 0
   and sc.PortfolioId = @portfolioid
   and IsNull(r.IsMemo, 0) = 0)
   and v.ResultSet In (0, 4)
   and i.AccountNumber not in
          ('401XX', '401ZZ','403ZZ','40310','41110',
           '42010','41510','40190','40110')
   and v.[Date] BETWEEN @fromdate AND 
            CASE WHEN pa.AnalysisEnd < @todate 
                 THEN pa.AnalysisEnd ELSE @todate END
   and ((i.LineItemTypeId = 3002 and i.BusinessEntityTypeId = 11) OR 
           (i.ModeledEntityKey = 1 and i.LineItemTypeId IN 
               (2005, 2010, 2003, 2125, 2209, 5012, 6001)))

GROUP BY pa.AnalysisBegin,pa.Id, pa.ExternalID, i.AccountNumber, 
      ac.[Description],cl.Name,ty.Name,v.[Date]
HAVING SUM(v.amount) <> 0