Instead of calling COUNT(*) with a WHERE clause, is there anything one can do to make this work more efficiently on the server? I would like to get this count on complicated joins, just wondering the best way to do this. Using SET NOCOUNT OFF? Because SET NOCOUNT ON is enabled by default in a new stored procedure and is suggested I guess by Microsoft. Thank you.
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possible duplicate of Does running a COUNT() statement using NOCOUNT ON; consume much– Jack DouglasSep 1, 2011 at 19:58
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1 Answer
SET NOCOUNT has nothing to do with your ability to perform counts or the efficiency of doing so. This setting merely enables the reporting of affected rowcounts to the client (e.g. the n row(s) affected. message in Management Studio). The reason it is recommended to be off is because it is unnecessarily chatty and can break some applications / APIs.
As for getting more efficient counts from complex joins, it's possible that your joins could be made more efficient, but we can't see them. It's also possible that you can pay that cost at a different time by using filtered indexes, indexed views, or pre-aggregating yourself at insert/update time, using a trigger, etc. Sometimes this can pay off but other than a general suggestion there's not much else we'll be able to offer you without a lot more details.
answered Sep 1, 2011 at 19:25
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Hello Aaron, in regards to your last response as well from question here: dba.stackexchange.com/questions/5293/… I am wondering the results in your SQL statement, i cannot see how to narrow down to one particular db/table, just a list of objects with a rowcount. Can you please elaborate on this as well?– WilkinsSep 1, 2011 at 19:29
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You would add an additional
WHEREclause, e.g.FROM sys.dm_db_partition_stats WHERE [object_id] = OBJECT_ID('dbo.tablename') AND ...- and you would run the query in the specific database or usedatabasename.sys.dm_db_partition_stats... Sep 1, 2011 at 19:37