SQL Server 2005 Column (Lazy spool) - Performance

Question

I have legacy SQL (SP)

  declare @FactorCollectionId       int;        select  @FactorCollectionId = collectionID from dbo.collection where name = 'Factor'
    declare @changeDate             datetime;   set @changeDate = getDate()
    declare @changeTimeID           int;        set @changeTImeID = convert(int, convert(varchar(8), @changeDate, 112))
    declare @MaxWindowID            int;        select @MaxWindowID = MAX(windowID) from dbo.window

  select distinct @FactorCollectionId, ElementId, T.TimeID, @changeTimeId ChangeTimeID, 1 UserID, @MaxWindowID, 0 ChangeID
                            , null TransactionID, SystemSourceID, changeTypeID, 'R' OlapStatus, Comment, Net0 Delta0, Net0
                            , 1 CreatedBy, 1 UpdatedBy, @changeDate CreatedDate, @changeDate UpdatedDate, 1 CurrentRecord, MeasureTypeID
                from dbo.aowCollectedFact FV
                    inner join dbo.timeView T on T.timeID >= FV.timeID
                where FV.currentRecord = 1                              --is current record
                    and T.CurrentHorizon <> 0                           --Indicator that Time is part of current horizon
                    and FV.collectionID = @FactorCollectionId           --factor collections only
                    and FV.timeID = (select  MAX(timeID)                --latest collected fact timeID for given collectionID and elementID
                                        from    aowCollectedFact FV2
                                        where   FV2.collectionId = @FactorCollectionId
                                            and FV2.elementId = FV.elementID)
                    and (((T.ForecastLevel = 'Month') and (T.FirstDayInMonth = T.Date))     --Date is first of month for monthly customers, or
                            or 
                        ((T.ForecastLevel = 'Quarter')and (T.FirstDayInQuarter = T.Date)))  --Date is first of quarter for quarterly customers
                    and not exists (select  1                                               --Record does not already exist in collected fact view
                                    from    aowCollectedFact FV3                            --  for this factor collection, elementID, and timeID
                                    where   FV3.collectionId = @FactorCollectionId
                                        and FV3.elementID = FV.elementId
                                        and FV3.timeID = T.timeID)

This SQL processes over 2 million rows. I need to improve his work. When I look at the execution plan, I find that a lot of time is spent on the operation Table Spool (Lazy spool)(indexes exist in tables, and they work well).

How to improve performance for this part?

Answer 1

Before looking at the execution plan or tables, I will give the best enlightened guesses. Firstly, here are a couple of links worth reading.

showplan operator of the week - lazy coil

Table reel / Lazy spool

. , , , . , JOINs WHERE . , SELECT, .

. , non equals ( "< > " ) , . and T.CurrentHorizon <> 0 and T.CurrentHorizon > 0?

JOINS: , . , and FV2.elementId = FV.elementID . , JOIN dbo.aowCollectedFact FV, , GROUPING (DISTINCT) .

DISTINCT: GROUP BY. , .

. IF NOT EXISTS . JOIN, LEFT JOIN...WHERE NULL, . .