Question

I currently have a stored procedure that copies content from one table to another.

However when it is trying to only insert 27 new rows it continues on for over 12 minutes (after which point I stopped it) it said Affected 27 rows 4 times, however changes were not made.

Can you spot any reason the following SP would be slow?

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER Procedure [dbo].[sp_CopyCompanyContent]
(
        @intCopyFromCompanyID Int,
        @intNewCompanyID Int
)
As
Begin
    /*
        RaisError If any of Odl/New Company ID's are 0
    */

    If (@intCopyFromCompanyID = 0 Or @intNewCompanyID = 0)
        Begin
            RaisError('New Company ID or Old Company ID can not be 0', 16, 1)
            Return
        End


    /*
        Create Temp Table For the Content Sections
    */

    If Object_ID('tempdb..#ContentSections') IS Not Null
        Begin 
            Drop Table dbo.#ContentSections
        End 

    /*
        Have to get all the existing data for the Old company we are copying from.
        Have to also add the Max(ContentSectionID) From ContentSection. Max(ContentSectionID) + 
        The Identity (Added further down due to laziness) will be our seed for the ContentID
    */

    Select      CS.ContentID,
                CS.SectionID,
                CS.MenuOrder,
                @intNewCompanyID NewCompanyID,
                CS.CompanyID OldCompanyID,
                CS.SubMenu,
                CS.Link,
                CS.HeaderMenu,
                CS.ParentContentID,
                CRS.*

    Into        dbo.#ContentSections

    From        dbo.Company COMP
    Join        dbo.ContentSection CS
    On          COMP.Company_id = CS.CompanyID  
    Join        dbo.Content CONT
    On          CONT.ContentID = CS.ContentID

    Cross Join  (
                    Select  MAx(ContentSectionID) MaxContentSectionID
                    From    dbo.ContentSection CONT
                ) crs

    Where       COMP.Company_id  = @intCopyFromCompanyID
    Order By    COMP.Company_id


    /*
        We now need to create a table for the existing content for the old company.
        Also have to create the seed. Same principle as above.
    */


    If Object_ID('tempdb..#Content') IS Not Null
        Begin 
            Drop Table dbo.#Content
        End 

    Select  CONT.*, 
            CRS.*

    Into    dbo.#Content

    From    dbo.Company COMP
    Join    dbo.ContentSection CS
    On      COMP.Company_id = CS.CompanyID  
    Join    dbo.Content CONT
    On      CONT.ContentID = CS.ContentID

    Cross Join  (
                    Select  MAx(ContentID) MaxContentID
                    From    dbo.Content CONT
                ) crs

    Where   COMP.Company_id  = @intCopyFromCompanyID
    Order By COMP.Company_id

    /*  
        Add Identity to each of the tables we have created above. The ID fields will add to 
        the Max of each table to mimic what the future seeds will be.
    */

exec('Alter table #ContentSections Add ID Int Identity(1,1)')
exec('Alter table #Content Add ID Int Identity(1,1)')

    /*
        Add content data from the temp table.
    */


    Insert  Into dbo.Content
    (
            Title,
            Content
    )   
    Select  Title,
            Content 
    From    dbo.#Content

    /*
        Have to the Content table up to the content sections table
        as this contains what ID has been add to the Content Table. 
    */


    Insert Into dbo.ContentSection
    (
            ContentID,
            SectionID,
            MenuOrder,
            CompanyID,
            SubMenu,
            Link,
            HeaderMenu,
            ParentContentID
    )

    Select  C.MaxContentID + C.ID,
            CS.SectionID,
            CS.MenuOrder,
            CS.NewCompanyID,
            CS.Submenu,
            CS.Link,
            CS.HEaderMEnu,
            CS.ParentContentID
    From    dbo.#Content C
    Join    dbo.#ContentSections CS
    On      C.ID = CS.ID

End

Answer 1

First thing to do is check the query plan for the selects since cross joins are dangerous beasts, if i’m not reading it wrong you’d display the same value in CRS.* in every record right?
If so, make that query before the select and stored the result in a variable and display it in the select, something like this.

DECLATE @maxValue INTEGER
Select  @maxValue=MAX(ContentID) MaxContentID
                    From    dbo.Content CONT
Select  CONT.*, 
            @maxValue as MaxContentID

    Into    dbo.#Content

    From    dbo.Company COMP
    Join    dbo.ContentSection CS
    On      COMP.Company_id = CS.CompanyID  
    Join    dbo.Content CONT
    On      CONT.ContentID = CS.ContentID
    Where   COMP.Company_id  = @intCopyFromCompanyID
    Order By COMP.Company_id