Doubt on Dynamic SQL

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Doubt on Dynamic SQL

balasach82

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April 7, 2014 at 1:56 pm

#306318

I have a set of 5 queries as 5 rows in a table. I am looping 1 by 1 and execute the queries, 5 in all, using sp_exectuesql
what is happening now is .. one query executes and before it completes, the loop goes to the next query and starts running.. It is causing problems like blocking, incorrect results etc.
How this can be avoided so that one query is executed only after the previous quey completes.. like in successsion 1 then 2 then 3 then 4 then 5.

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Sean Lange SSC Guru Points: 286590 More actions · Answer 1

balasach82 (4/7/2014)
I have a set of 5 queries as 5 rows in a table. I am looping 1 by 1 and execute the queries, 5 in all, using sp_exectuesql
what is happening now is .. one query executes and before it completes, the loop goes to the next query and starts running.. It is causing problems like blocking, incorrect results etc.
How this can be avoided so that one query is executed only after the previous quey completes.. like in successsion 1 then 2 then 3 then 4 then 5.

Why are you storing sql in a table?

I take it you have these queries stored and then you create a cursor to pull all the information and then execute them one at a time? What are you doing with the results? Without more details it is difficult to guess what you are trying to do. However, I am pretty sure we can come up with a better approach.

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Lynn Pettis SSC Guru Points: 442467 More actions · Answer 2

Since we can't see what you see, hard to say. However, since sp_exectuesql is a synchronous call, I would be curious to know how another one can start executing if the first one is still running.

Jeff Moden SSC Guru Points: 1004406 More actions · Answer 3

balasach82 (4/7/2014)
I have a set of 5 queries as 5 rows in a table. I am looping 1 by 1 and execute the queries, 5 in all, using sp_exectuesql
what is happening now is .. one query executes and before it completes, the loop goes to the next query and starts running.. It is causing problems like blocking, incorrect results etc.

A loop and sp_ExecuteSQL wouldn't do such a thing. Please post the code you're using.

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SQLb2t Say Hey Kid Points: 662 More actions · Answer 4

SQLb2t

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April 7, 2014 at 6:09 pm

#1703989

post the code...ideally it should not

balasach82 SSCrazy Eights Points: 9653 More actions · Answer 5

I am using cursor for the loop. It is an rebuild operation query. I am also testing the same logic for taking backup/restore, file cleanup from folders.

I faced this error--

Could not proceed with index DDL operation on table 'some table' because it conflicts with another concurrent operation that is already in progress on the object. The concurrent operation could be an online index operation on the same object or another concurrent operation that moves index pages like DBCC SHRINKFILE.

Gail Shaw SSC Guru Points: 1004504 More actions · Answer 6

There's another session from somewhere else which is causing this. Identify where that other session is coming from.

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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balasach82 SSCrazy Eights Points: 9653 More actions · Answer 7

Awesome. A job ws running which was running the query. Thanks for pointing to the problem.

So, its 100% sure that an sp_execsql does not pass control untill the query is completed?

Grant Fritchey SSC Guru Points: 398909 More actions · Answer 8

balasach82 (4/8/2014)
Awesome. A job ws running which was running the query. Thanks for pointing to the problem.
So, its 100% sure that an sp_execsql does not pass control untill the query is completed?

Yes.

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