June 23, 2005 at 7:53 am
Hello friends!!
In Execution plan please somebody help me to understand I am new to it.
If I run one select statement having Execution plan...
1.first of all what we will watch closely so that it will understand easily i.e related to costing....
2.Here I am seeing factors like 'SELECT' ,' TOP' , Hash Match/Left Anti Semi Join.
3.Index Scan : Physical Operation and Logical Operation
Here only I can see some factores like
Physical Operation And Logical Operation
a)Row Count =========== 26,795,748
b)Estimated Row Size ==== 132 (What this exactly means??)
c)I/O Cost ============ 209
d)CPU Cost ============ 29.5
e)Number Of Executes === 1
f)Cost ============== 238.884090(57%)
h)Subtree Cost ======== 417
i)Estimated Row Count==== 26,795,748
4.Computer Scalar:
5.Stram Aggregate/Aggregate
6.Table Scan
Like That........
Please somebody guide me in that I will be thankful.. (Please Give me detail description where i can judge all factors of execution plan so that i can reduce the cost of query if possible)
T.I.A
Shashank
Regards,
Papillon
June 23, 2005 at 8:05 am
Can you rerun the query like this and post the actualy text plan?
set showplan_text ON
GO
--select query
GO
set showplan_text off
June 23, 2005 at 8:08 am
a) 26M is a lot of rows.. are you sure you need that much???
b) size of the row for the selected columns (int = 4, tinyint = 1...)
F) one of the most important... relative cost to the query, tells you what's slowing down the whole thing.
6) Really bad... should be a clustered index scan at worse.
June 24, 2005 at 4:11 am
Hey guys!!!!!!!
Thanks Really That helped me alot!!!
Shashank
Regards,
Papillon
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