Question

I am using a SP which takes around a minute to execute; any ideas for optimisation? For indexing I am using is the accessCodeID, amount of data is around 20k,

 SELECT COUNT(tbAC.abGUID) AS total,
       tbAC.abGUID,
       tbAC.aVID,
       tb_tt.used,

FROM   tbAC
       INNER JOIN (SELECT COUNT(abGUID) AS used,
                          abGUID
                   FROM   tbAC AS tbAC_1
                   WHERE  ( batchGUID = @id )
                          AND ( aVID > 0 )
                          AND ( isVoided = 0 )
                          AND ( isCodeUsed = 1 )
                   GROUP  BY abGUID) AS tb_tt
         ON tbAC.abGUID = tb_tt.abGUID
       INNER JOIN tbV
         ON tbAC.aVID = tbV.vendorID
WHERE  ( tbAC.aVID > 0 )
       AND ( tbAC.batchGUID = @id )
       AND ( tbAC.isVoided = 0 )
       AND ( lowLevelNotified = 0 )
GROUP  BY tbAC.abGUID,
          tbAC.aVID,
          tb_tt.used,
          tbV.name,
          tbV.firstName,
          tbV.lastName,
          tbV.tel,
          tbV.email,
          tbV.contactName  

Answer 1

Assuming allocatedVendorID is functionally dependant on abGUID, try:

SELECT sum(case when lowLevelNotified = 0 then 1 else 0 end) AS total,
       tbAccessCode.abGUID,
       tbAccessCode.allocatedVendorID,
       sum(case when isCodeUsed = 1 then 1 else 0 end) AS used,
       tbV.name,
       tbV.firstName,
       tbV.lastName,
       tbV.tel,
       tbV.email,
       tbV.contactName
FROM   tbAccessCode
       INNER JOIN tbV
         ON tbAccessCode.allocatedVendorID = tbV.vendorID
WHERE  ( tbAccessCode.allocatedVendorID > 0 )
       AND ( tbAccessCode.batchGUID = 'abc-def' )
       AND ( tbAccessCode.isVoided = 0 )
GROUP  BY tbAccessCode.abGUID,
          tbAccessCode.allocatedVendorID,
          tbV.name,
          tbV.firstName,
          tbV.lastName,
          tbV.tel,
          tbV.email,
          tbV.contactName