SQL Server Performance Forum – Threads Archive
select query with waittype NETWORKIO
Hello, I am running select query with (nolock) and I am select * from mytable. I have about 243K records and there is no PK and index on table. But it was going beyond 21mins so I killed the query it was able to retrive only 165K row back to client. when query was running and I checked on SQL processes side, I found that my query waittype is NETWORKIO. The database is hosted on 8way cpu cluster enviornment with 1gig network card attached. so I select query is slow and waittype is networkio. I do agree that there is PK and index required that is one recommendation, I have but still I am not convience that it takes beyond 25mins to retrive data?Is there anything else I should be looking at? thanksbasic investigation 101 compare the execution plans for
SELECT * FROM MyTable
SELECT COUNT(*) FROM MyTable since there are no PK or indexes, both plans should be a full table scan
so the difference is the time to send the results over the network you could even try SELECT Col1 FROM MyTable
start with the smallest column, then try a bigger column
See thishttp://support.microsoft.com/kb/884554 is any help here. Satya SKJ
Microsoft SQL Server MVP
Writer, Contributing Editor & Moderator
http://www.SQL-Server-Performance.Com
This posting is provided AS IS with no rights for the sake of knowledge sharing. Knowledge is of two kinds. We know a subject ourselves or we know where we can find information on it.
Thanks!
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