Execution Plan "table Spool"

Question

Execution Plan "table Spool"

meerack11

Right there with Babe

Points: 767
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August 14, 2015 at 8:39 am

#303477

Hello friends
I found table spool(Lazy) in execution plan so it is better or not?
let me know if it is not good then how to avoid it?

Viewing 5 posts - 1 through 4 (of 4 total)

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ChrisM@Work SSC Guru Points: 186127 More actions · Answer 1

meerack11 (8/14/2015)
Hello friends
I found table spool(Lazy) in execution plan so it is better or not?
let me know if it is not good then how to avoid it?

It depends on what the statement is doing. Folks will be guessing without sight of the actual query plan.

^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

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Eirikur Eiriksson SSC Guru Points: 182882 More actions · Answer 2

Further on Chris's reply, this is a high level representation of what goes on behind the scene when a query is executed, it can be good, bad or ugly but it all depends, without more complete information it's a waste of time trying to guess.

😎

Best thing you can do to get an answer to your question is to post the actual execution plan, the DDL (create table including indices etc.) and at least some information on the data (cardinality etc.)

meerack11 Right there with Babe Points: 767 More actions · Answer 3

Select distinct SCode, Spec from CLEANSED_DATA

where State ='NC' and Application_Header_ID=82 and Ntwk_ID='NCN201' and File_Type='Provider'

and SCode not in

(select Spec_Code from vw_Geo

where State='NC' and File_Type='Provider' and

Application_Header_ID=82 and NetworkID='N201'

)

and I have also question like what is better multiple non cluster index pr multiple column non cluster index?

Gail Shaw SSC Guru Points: 1004504 More actions · Answer 4

Seconding Chris's request to see the execution plan. The query alone is not very useful.

As for indexes: http://sqlinthewild.co.za/index.php/2010/09/14/one-wide-index-or-multiple-narrow-indexes/

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

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