Question

I would like to find out or at least estimate how much memory does a single query (a specific query) eats up while executing. There is no point in posting the query here as I would like to do this on multiple queries and see if there is a change over different databases. Is there any way to get this info?

Using SQL Server 2008 R2

thanks

Gilad.

Answer 1

You might want to take a look into DMV (Dynamic Management Views) and specifically into sys.dm_exec_query_memory_grants. See for example this query (taken from here):

DECLARE @mgcounter INT
SET @mgcounter = 1
WHILE @mgcounter <= 5 -- return data from dmv 5 times when there is data
BEGIN
    IF (SELECT COUNT(*)
      FROM sys.dm_exec_query_memory_grants) > 0
    BEGIN
             SELECT *
             FROM sys.dm_exec_query_memory_grants mg
                         CROSS APPLY sys.dm_exec_sql_text(mg.sql_handle) -- shows query text
             -- WAITFOR DELAY '00:00:01' -- add a delay if you see the exact same query in results
             SET @mgcounter = @mgcounter + 1
    END
END

While issuing the above query it will wait until some query is running and will collect the memory data. So to use it, just run the above query and after that your query that you want to monitor.