All Questions
16
questions
5
votes
1
answer
104
views
Analyising Implict CAST
I have an academic scenario, which I would like to know how to analyse.
DECLARE @date DATETIME
SET @date = getDate()
SET @date = DATEADD(DAY, DATEDIFF(DAY, 0, @date-3), 3)
This will round ...
- 85.8k
2
votes
2
answers
98
views
Question on Query execution
In the below query if the Patients table has 1000 records how many times TableValueFunction executes? Only once or 1000 time?
This is a query in a Stored Procedure, do you have a better idea to ...
- 47k
3
votes
5
answers
211
views
SQL select field causing major performance problem
I have a stored procedure that joins in numerous tables and selects fields from them. One of the tables being a temporary table.
SELECT
a.Field1,
a.Field2,
b.Field3,
b.Field4,
c....
- 38.4k
1
vote
2
answers
4k
views
Getting query / execution plan for dynamic sql in SQL Server [duplicate]
Possible Duplicate:
How do I obtain a Query Execution Plan?
how can I see the execution plan in SQL Server 2005 for a dynamic sql that is executed? I cannot save any files on the computer where ...
- 2,046
9
votes
3
answers
8k
views
SQL Server sp_ExecuteSQL and Execution Plans
I have a query which is super fast in SQL Server Management Studio and super slow when run under sp_ExecuteSQL.
Is this to do with caching of execution plans not happening when run under sp_ExecuteSQL?...
- 32.4k
2
votes
1
answer
69
views
Adding inner query is not changing the execution plan
Consider the following queries.
select * from contact where firstname like '%some%'
select * from
(select * from contact) as t1
where firstname like '%some%'
The execution plans for both ...
- 15.4k
1
vote
2
answers
461
views
Different execution plan for similar queries
I am running two very similar update queries but for a reason unknown to me they are using completely different execution plans. Normally this wouldn't be a problem but they are both updating exactly ...
2
votes
2
answers
2k
views
No query plan for procedure in SQL Server 2005
We have a SQL Server DB with 150-200 stored procs, all of which produce a viewable query plan in sys.dm_exec_query_plan except for one. According to http://msdn.microsoft.com/en-us/library/ms189747....
- 1,110
3
votes
4
answers
631
views
Caching SQL execution plans
I know SQL server 2005 does some amount of execution plan caching, but would that be enough to create a difference of hours between the same query being run twice? The first time it takes 3 hours the ...
- 407
2
votes
4
answers
1k
views
Does the sequence in which we use join in a query effects its execution time?
Does the sequence in which we use join in a query effects its execution time ?
- 5,730
6
votes
4
answers
4k
views
Question on how to read a SQL Execution plan
I have executed a query and included the Actual Execution Plan. There is one Hash Match that is of interest to me because it's subtree uses a Index Scan instead of an index seek. When I mouse over ...
- 84.3k
0
votes
4
answers
236
views
Is my execution plan trying to trick me?
I am trying to speed up a long running query that I have (takes about 10 minutes to run...). In order to track down what part of the query is costing me the most time I included the Actual Execution ...
- 84.3k
1
vote
3
answers
1k
views
T-SQL Process Design and Execution Plan (UDF Parameter Sniffing?)
On SQL Server 2005, I have a complex multi-level allocation process which looks like this (pseudo-SQL):
FOR EACH @LVL_NUM < @MAX_LVL:
INSERT INTO ALLOCS
SELECT 'OUT', *
FROM BALANCES(@LVL_NUM)
...
- 89.2k
55
votes
6
answers
139k
views
Measuring Query Performance : "Execution Plan Query Cost" vs "Time Taken"
I'm trying to determine the relative performance of two different queries and have two ways of measuring this available to me:
1. Run both and time each query
2. Run both and get "Query Cost" from the ...
- 85.8k
4
votes
6
answers
6k
views
Different Execution Plan for the same Stored Procedure
We have a query that is taking around 5 sec on our production system, but on our mirror system (as identical as possible to production) and dev systems it takes under 1 second.
We have checked out ...
- 17.7k