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can lot of CASTs/Union or ISNULL possibly cause blocks?

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Last Modified: 2014-11-25
This query runs fine every day scheduled.. but yesterday, it was blocked by itself in sysprocesses.. when I did select * from master..sysprocesses where blocked<>0 I saw 12 lines all for this one process running this, and all with same spid and same blocked column data.

is it because of excessive UNION/CAST etc. CAn you suggest?
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Commented:
The actual processing is from stored proc.. but I put it as code format by substituting the parameter values here to illustrate, any thoughts on making this code efficient to avoid blocks/locks?

 ~~~~~~~~~~~~~~~~~~~~~~
SET NOCOUNT ON        
        
DECLARE @JobYear varchar(4)          
SET @JobYear = '2004'        
DECLARE @PairedID char(3)          
SET @PairedID = '113'         
        
        
DECLARE @ExtractDt datetime        
SET @ExtractDt = (Select Distinct Max(dbo.PASNote.ExtractDt)         
   From dbo.PASNote         
   Where dbo.PASNote.JobYear = @JobYear)        
        
DECLARE @PPExtractDate datetime        
SET @PPExtractDate = (Select Distinct  PPExtractDate        
   From dbo.PASNote         
   Where dbo.PASNote.JobYear = @JobYear        
               And ExtractDt = @ExtractDt)        
          
 Select         
 CAST(@JobYear as char(4))         
        + '-'        
        + CAST(@JobYear+1 as char(4)) As [JobYear],        
 CAST([PairID] as int) As [FinalizedPair],        
          CAST([BCPERName] as varchar(60)) As [FinalizedBCPER],        
        CAST([UCANName] as varchar(30)) As [FinalizedUCAN],        
        CAST((SUBSTRING(Cast([PairID] as char),1,1) + '-'        
         + SUBSTRING(Cast([PairID] as char),2,2) + '-'        
          + SUBSTRING(Cast([PairID] as char),4,2) + '-'        
           + SUBSTRING(Cast([PairID] as char),6,3) + '-'        
          + SUBSTRING(Cast([PairID] as char),9,1)) as varchar(30)) As [mtPair],        
        CAST(TempTable.[PickID] as varchar(4)) PickID,        
        CASE WHEN TempTable.[PickID]  IN('J2','J3','J4','J5','J6') THEN 'J2'        
                    WHEN TempTable.[PickID]  IN('M2','M3') THEN 'M2'           
                    ELSE  TempTable.[PickID]   END AS  [PickGroupCd],        
 CAST(' ' as varchar(60)) As [RegulatingNUA],        
        CAST(' ' as varchar(30)) As [SchedProgramCd],        
 CAST(' ' as varchar(30)) As [SchedIdCd],        
CAST(' ' AS VARCHAR(5)) AS [LeadStatusCd],        
CAST(' ' AS VARCHAR(5)) AS [PLKStatusCd],        
 CAST(0 as smallint) As [PeakedCap],        
 CAST(0 as int) As [Accumul],        
        CAST(0 as decimal(18,3)) As [PeakedMDT],        
 CAST(0 as decimal(18,5)) As [PaceAdj],        
        CAST(0  as dec(13,0)) as [PrePHCstDst],        
 CAST(0  as dec(13,3)) as [PrePHMDT],        
 CAST(0  as dec(13,0)) as [PrePTCstDst],        
 CAST(0  as dec(13,3)) as [PrePTMDT],         
        CAST(0  as dec(13,0)) as [PeakedPHForCstDst],        
        CAST(0  as dec(13,3)) as [PeakedPHForMDT],        
        CAST(0  as dec(13,0)) as [PeakedPTForCstDst],        
        CAST(0  as dec(13,3)) as [PeakedPTForMDT],        
 CAST(0  as dec(13,0)) as [PHJustForCstDst],        
 CAST(0  as dec(13,3)) as [PHJustForMDT],        
 CAST(0  as dec(13,0)) as [PTJustForCstDst],        
 CAST(0  as dec(13,3)) as [PTJustForMDT],        
 CAST(0  as dec(13,0)) as [PHPunchCstDst],        
 CAST(0  as dec(13,3)) as [PHPunchMDT],        
 CAST(0  as dec(13,0)) as [PTPunchCstDst],        
 CAST(0  as dec(13,3)) as [PTPunchMDT],        
 CAST(0  as dec(13,0)) as [BaseCstDst],        
 CAST(0  as dec(13,3)) as [BaseMDT],        
 CAST(0  as dec(13,0)) as [AdvCstDst],        
 CAST(0  as dec(13,3)) as [AdvMDT],        
        CAST([UCANName] as varchar(30)) AS [UCANName],        
        Cast(@ExtractDt As datetime) As [ExtractDt],        
        Cast(@PPExtractDate as datetime) AS [PPExtractDate]        
 FROM  dbo.CI_NUA         
        INNER JOIN         
        (SELECT CAST('DX' AS VARCHAR(10)) AS [NUACTGY],        
       CAST(TBLSC.[PickID] AS VARCHAR(4)) PickID        
       FROM        
       (SELECT CAST('A1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('A2' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('A3' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('B1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('C1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('D1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('D2' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('E1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('E2' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('F1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('G1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('H1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('I1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('J1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('K1' AS VARCHAR(4)) PickID        
 UNION ALL        
       SELECT CAST('L1' AS VARCHAR(4)) PickID        
       UNION ALL        
  SELECT CAST('L2' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('M1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('N1' AS VARCHAR(4)) PickID        
       UNION ALL        
       SELECT CAST('O1' AS VARCHAR(4)) PickID        
     ) AS TBLSC        
       ) AS TempTable        
       ON dbo.CI_NUA.[BCPERAbbr] = TempTable.[NUACTGY]        
       AND dbo.CI_NUA.[JobYearFK] = @JobYear        
        WHERE [BCPERAbbr] = 'DX' AND PairID = @PairedID        
        AND TempTable.[PickID] NOT IN        
        (SELECT DISTINCT [ReportPickID]        
                FROM dbo.PASNote         
                WHERE GroupPair = @PairedID AND ExtractDt = @ExtractDt      
                AND [JobYear] = @JobYear)        
--         
--        
Union All          
--        
-- Select Note report lines from table dbo.PASNote         
--        
 Select         
 CAST(JobYear as char(4)) + '-' +        
        CAST((CAST(JobYear as dec(4,0)) + 1) as char(4)) As [JobYear],        
 CAST(GroupPair as int) As [FinalizedPair],        
        CAST(NUA.[BCPERName] as varchar(60)) As [FinalizedBCPER],        
        CAST(NUA.[UCANName] as varchar(30)) As [FinalizedUCAN],        
        CAST((SUBSTRING(Cast([GroupPair] as char),1,1) + '-'        
         + SUBSTRING(Cast([GroupPair] as char),2,2) + '-'        
          + SUBSTRING(Cast([GroupPair] as char),4,2) + '-'        
           + SUBSTRING(Cast([GroupPair] as char),6,3) + '-'        
          + SUBSTRING(Cast([GroupPair] as char),9,1)) as varchar(30)) As [mtPair],        
        CAST(ReportPickID as varchar(4)) PickID,        
        CASE WHEN ReportPickID  IN('J2','J3','J4','J5','J6') THEN 'J2'        
                    WHEN ReportPickID  IN('M2','M3') THEN 'M2'        
                    ELSE  ReportPickID   END AS  [PickGroupCd],        
 CAST(RegulatingBCPERName as varchar(60)) As [RegulatingNUA],        
        CAST(IsNull(SchedProgramCd,' ') as varchar(30)) As [SchedProgramCd],        
 CAST(IsNull(SchedIdCd,' ') as varchar(30)) As [SchedIdCd],        
    CAST([LeadStatusCd] AS VARCHAR(5)) AS [LeadStatusCd],        
CAST([PLKStatusCd] AS VARCHAR(5)) AS [PLKStatusCd],        
 CAST(IsNull(PeakedCap,0) as smallint) As [PeakedCap],        
 CAST(IsNull(Accumul,0) as int) As [Accumul],        
        CAST(IsNull(PeakedMDT1,0) as decimal(18,3)) As [PeakedMDT],        
 CAST(IsNull(DistrictPaceAdj,0) as decimal(18,5)) As [PaceAdj],        
        CAST(IsNull(PrePHCstDst,0)  as dec(13,0)) as [PrePHCstDst],        
 CAST(IsNull(PrePHMDT,0)  as dec(13,3)) as [PrePHMDT],        
 CAST(IsNull(PrePTCstDst,0)  as dec(13,0)) as [PrePTCstDst],        
 CAST(IsNull(PrePTMDT,0)  as dec(13,3)) as [PrePTMDT],         
        CAST((CAST(IsNull(PHJustForCstDst,0)  as dec(13,0)) + CAST(IsNull(PHPunchCstDst,0)  as dec(13,0)))  as dec(13,0)) as [PeakedPHForCstDst],        
        CAST((CAST(IsNull(PHJustForMDT,0)  as dec(13,3)) + CAST(IsNull(PHPunchMDT,0)  as dec(13,3)))  as dec(13,3)) as [PeakedPHForMDT],        
        CAST((CAST(IsNull(PTJustForCstDst,0)  as dec(13,0)) + CAST(IsNull(PTPunchCstDst,0)  as dec(13,0)))  as dec(13,0)) as [PeakedPTForCstDst],        
        CAST((CAST(IsNull(PTJustForMDT,0)  as dec(13,3)) + CAST(IsNull(PTPunchMDT,0)  as dec(13,3)))  as dec(13,3)) as [PeakedPTForMDT],        
 CAST(IsNull(PHJustForCstDst,0)  as dec(13,0)) as [PHJustForCstDst],        
 CAST(IsNull(PHJustForMDT,0)  as dec(13,3)) as [PHJustForMDT],        
 CAST(IsNull(PTJustForCstDst,0)  as dec(13,0)) as [PTJustForCstDst],        
 CAST(IsNull(PTJustForMDT,0)  as dec(13,3)) as [PTJustForMDT],        
 CAST(IsNull(PHPunchCstDst,0)  as dec(13,0)) as [PHPunchCstDst],        
 CAST(IsNull(PHPunchMDT,0)  as dec(13,3)) as [PHPunchMDT],        
 CAST(IsNull(PTPunchCstDst,0)  as dec(13,0)) as [PTPunchCstDst],        
 CAST(IsNull(PTPunchMDT,0)  as dec(13,3)) as [PTPunchMDT],        
 CAST(IsNull(BaseCstDst,0)  as dec(13,0)) as [BaseCstDst],        
 CAST(IsNull(BaseMDT,0)  as dec(13,3)) as [BaseMDT],        
 CAST(IsNull(AdvCstDst,0)  as dec(13,0)) as [AdvCstDst],        
 CAST(IsNull(AdvMDT,0)  as dec(13,3)) as [AdvMDT],        
      CAST(NUA.UCANName as varchar(30)) AS [UCANName],        
        Cast(ExtractDt As datetime) As [ExtractDt],        
        Cast(PPExtractDate As datetime) As [PPExtractDate]        
 FROM  dbo.PASNote         
        Inner Join dbo.CI_NUA NUA        
        On dbo.PASNote.GroupPair = NUA.PairID        
        AND NUA.[JobYearFK] = @JobYear        
        WHERE        
        JobYear = @JobYear and      
        GroupPair = @PairedID AND        
        ExtractDt = @ExtractDt        
   
 Order by FinalizedPair,         
                 PickID,RegulatingNUA,        
                 PeakedCap,SchedIdCd         
        
SET NOCOUNT OFF

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Vitor MontalvãoIT Engineer
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Distinguished Expert 2017

Commented:
What causes locks are long running queries. How long usually this query takes to run?

Author

Commented:
right now it just ran in 3 seconds..  it has run scheduled for many months.. it was just yesterday that this has misbehaved (that we saw)..

what was puzzling was generally in sysprocesses, the blocked id is different than spid.. but here spid was same as blocked id and also several lines...
Vitor MontalvãoIT Engineer
CERTIFIED EXPERT
Distinguished Expert 2017
Commented:
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PortletPaulEE Topic Advisor
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Commented:
This one is on us!
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Author

Commented:
thank you. I will keep an eye on it.

Paul, appreciate your note.

do you have an mock tsql example to show how bad performance can deteriorate by adding a distinct?
EE Topic Advisor
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Awarded 2013
Commented:
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