Query Cost In Execution Plan
Apr 13, 2008what does query cost(retrive to the batch) mean in execution plan?
what is the differeence between query cost :100% and 65%?
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How Can I Get Actual Operation Cost From Actual Execution Plan?
Jul 25, 2006I have a view in SQLServer 2005. It took 30 sec. to finish. Then I deleted 4500 records from one table that is used in view. It took 90 sec. to finish now. I did a comparison on Actual Execution Plan between before I deleted data and after I deleted data, they are almost same, only different is Actual Number Rows become less after deleted data. So, I wonder why data become less but time become more. When I look closely on the Actual Execution Plan, the ridiculous thing is, there are only Estimated Operation Cost on each step, no Actual Operation Cost. I guess there are something wrong with optimizer because reuse same Execution Plan, but how can I tell which step wrong without Actual Operation Cost.
Thanks!
Henry
DB Engine :: Cost Vs Time When Including Actual Query Plan In SSMS
Nov 11, 2015I have two queries yielding the same result that I wanted to compare for performance. I did enter both queries in one Mangement Studio query window and execute them as one batch with the actual query plan included.Query 1 took 8.2 seconds to complete and the query plan said that the cost was 21% of the batchQuery 2 took 2.3 seconds to complete and the query plan said that the cost was 79% of the batch.The queries were run on my local development machine. I was the only user. No other programs were running at the time of this test. The results are repeatable.I understand that the query with the lowest cost is not necessarily the fastest query. On the other hand, the difference is quite big. The query that has approx. 80% of the cost takes 20% of the time and the other way around. I have two questions:
Is such a discrepancy normal?Can conclusions be drawn from the cost distribution? For instance, does the query that takes 8.2 seconds but only costs 21% scale better?
Query Analyzer -&> Subtree Cost Vs. Execution Time
Jul 14, 2004I am using a stored procedure that is behaving badly - the subtree cost is about 2000 and it takes between 3-4 seconds to run, and sometimes it takes over a minute to run. I have made some optimizations that cause the stored procedure to run in generally under 1 second (at most under 2 seconds), but the subtree cost of it jumps to 4000!! All of this while the server was experiencing similar load (the tests were done within minutes of each other).
I know that the subtree cost is a way to gauge the performance of a query against other queries, but I have typically seen the cost go in the same direction as the execution time (they both go up or the both go down).
How does SQL Server determine the cost (I know that is based on statistics, but I was wondering if anyone had more details)? Is it more important to have a lower subtree cost, or a lower execution time? Am I going to get into trouble later with this high subtree cost?
I would appreciate any help on this matter.
SQL 6.5 Query Execution Plan .
Sep 24, 2002Hello ,
I wanted to know whether we have an execution plan enabled in SQL 6.5 as we have it in SQL 7.0 and SQL 2000 .
I.e when we execute a query and if we enable ' show execution plan 'then it creates a map and shows the vital statistics .
If that is available on SQL 6.5 then i am missing that tool .
How can i have it installed on my SQL 6.5 server ??
Thanks.
DB Engine :: Multiple Execution Of Query Pattern Generates Same Query Plan
Oct 6, 2015SQL Server 2012 Performance Dashboard Main advices me this:
Since the application is from a vendor and I have no control over its code, how can improve this sitation?
SQL 2012 :: Same Query But Different Execution Plan
May 15, 2015I have same query but when executed from different server use different plan. when it runs on QA box it is faster and when it runs on PRD it is slow.
Is it possible to force SQL Server to use QA plan by giving a hint?
T-SQL (SS2K8) :: Query Not Use Same Execution Plan?
Jun 5, 2015if t-sql query is perfectly run in development and when I execute in production at that time I want to use execution plan which is in development . so how I can do using cache? I know about hint we can use hint USE_PLANE. but I want to do with cache .
View 1 Replies View RelatedExecution Plan In Query Analyzer
Jan 31, 2008This is probably a very stupid question. I have been out of the SQL Server arena for awhile and am now getting re acclimated. It was my understanding that using execution plan in query analyzer does not really execute the query against the query's database tables. Is this right? Tom.
View 1 Replies View RelatedView Query Execution Plan
Sep 15, 2007
Hi,
I am developing an application (VB) that should present a query estimated execution plan.
Using the SQL Server Management Studio, I should execute the following commands to see the query's estimated execution plan:
SET SHOWPLAN_XML ON
go
MyQuery
go
SET SHOWPLAN_XML OFF
go
The query is not executed. The result is the query execution plan.
In my application, I call Connection.Execute to execute the 'SET SHOWPLAN_XML ON'. Then, I use a Resultset submit the query. The query is executed and the execution plan is not returned.
Does anyone have any ideas?
Thanks
Actual Execution Plan Vs Estimated Execution Plan
Jul 7, 2006The benefit of the actual execution plan is that you can see the actual number of rows passing through each step - compared to the estimated number of rows.But what about the "cost percentages" ?I believe I've read somewhere that these percentages is still just an estimate and is not based on the real execution.Does anyone know this and preferable have a link to something that documents it?Thanks
View 1 Replies View RelatedQuery Optimizer/Wrong Execution Plan
Jul 6, 2001I have SQL 7.0 SP2 on NT 4.0 SP5. My database is 180GIG. 23 Tables. It has been up and running for 2 years without any problems. All of a sudden my queries have started taking a long time to run. The optimizer has decided that table scans are better than indexes. If I use query hints they work just fine, but I can't modify all of our code to make these changes.
This is happening on all tables. Records counts are the in the same range they have always been.
Statistics and indexes are all fine and current. Have dropped and rebuilt both.
Has anybody else seen this behavior.
Query Execution Plan Tutorial / Links
Apr 23, 2008Hi All,
I have to get some knowledge in Query Execution Plan.
Is there any links which i can refer for the same
Thanks,
Muthu
Error Loading Query Execution Plan
Oct 26, 2006I am trying to tune a very long running query (18 minutes on an Axim X51, 8secs on my laptop), but I can't get the query plan file that is generated on the device to load in the Sql Server Management Studio. I am using the Sql Everywhere CTP on the device, and version 9.00.2047 of the management studio shell.
FWIW, when I try to create the execution plan by running the same query on a .sdf file local on my laptop, I get a similar error trying to view the query plan.
Apart from the query plan issues, it would appear (just from the query execution time) that the indexes defined on the sdf file are not being used when executing the query on the device, but are being used when executing the query on the laptop. This is pure SWAG on my part, though.
I can't figure out how to attach a file to the post, unfortunately.
Thanks for any help you can offer.
Matthew Belk, BizSpeed, Inc.
SQL 2012 :: How To Run Query Execution Plan For Parameterized Queries
Jul 21, 2014know if there is any way out to run execution plan for parameterized queries?
As application is sending queries which are mostly parameterized in nature and values being used are very robust in nature, So i can not even make a guess.
Accessing Estimated Query Execution Plan (QEP) Statisitics
Jul 20, 2005Hi,I have a question about estimated query execution plans that aregenerated in QA of MSSQL.If I point at an icon/physical operator in the estimated QEP, it showsmesome statistics about the operator.Is there a way to retrieve these statistics through a query, i.e., canthese statistics be available to the user?Also, is there a way to generate these statistics on my own?thanks in advance-TC.
View 2 Replies View RelatedShow Execution Plan And Misleading Query Costs...
Jul 20, 2005Hi All,I'm a relative newbie to SQL Server, so please forgive me if this is adaft question...When I set "Show Execution Plan" on in Query Analyzer, and execute a(fairly complex) sproc, I note that a particular query is reported ashaving a query cost of "71% relative to the batch" - however, this isnowhere near the slowest executing query in the batch - other querieswhich take over twice as long are reported as having costs in theorder of a few percent each.Am I misreading the execution plan? Note that I'm looking at thegraphical plan, and am not reading the 'estimated' plan - I'm usingthe one generated from executing the sproc. My expectation was thatthis would be based on the execution times of the queries within thesproc, however, this does not appear to be the case. (Note - Idetermined execution times from PRINT statements, using GETDATE() todetermine the current time, down to milliseconds).Any feedback would be of great assistance... I may well have tochange the way I approach optimizing queries based on these findings.Thanks,LemonSmasher.
View 3 Replies View RelatedAccessing Query Execution Plan Results Programmatically
Mar 19, 2007Does anyone know if it is possible to access the execution plan results programmatically through a stored procedure or .NET assembly? I have the code sample
SET SHOWPLAN_XML ON; query... SET SHOWPLAN_XML OFF;
but it can only be run from the interface. I have tried a couple of solutions including dynamic sql to try to capture the results in a variable or file with no luck.
Does anyone know of a way to programmatically capture this information? We are doing some research with distributed query processing of dynamically generated queries using multiple processing nodes, and it would be helpful to know an estimate of how large the query is before sending it away to be processed.
I have looked at the dm_exec_query_stats view; but it can only be run on a query that has already been executed. I need to know the execution plan before the query is executed. If there is a way to get a query to show up in this view without being executed, then that would work as well.
Thanks -- MT
SQL Server 2008 :: Query Execution Plan Of Stored Procedure
Jun 17, 2015Is it possible to check query execution plan of a store procedure from create script (before creating it)?
Basically the developers want to know how a newly developed procedure will perform in production environment. Now, I don't want to create it in production for just checking the execution plan. However they've provided SQL script for the procedure. Now wondering is there any way to look at the execution plan for this procedure from the script provided?
SQL 2012 :: Check Query Execution Plan Of A Store Procedure From Create Script?
Jun 17, 2015Is it possible to check query execution plan of a store procedure from create script (before creating it)?
Basically the developers want to know how a newly developed procedure will perform in production environment. Now, I don't want to create it in production for just checking the execution plan. However they've provided SQL script for the procedure. Now wondering is there any way to look at the execution plan for this procedure from the script provided?
T-SQL (SS2K8) :: Finding Last Cost By Article And Compare With Invoice Line Cost?
May 28, 2015I need to build TSQL query to return the Last unit Cost from my table of movement of goods SL (on CTE) but the MAX(Datalc) must be Less or Equal to my HeaderInvoice.
This is my script:
With MaxDates as (
SELECT ref,
MAX(epcpond)[Unitcostprice],
MAX(datalc) MaxDate
FROM sl
[code]....
the problem I have right now is that the Unitcostprice of my table of goods movements has a top date greather than the date of my bill.
Example:
invoice date : 29.01.2015 unitcost on invoice line = 13,599722
Maxdate (CTE) : 19.03.2015 unitCost from my table of movement of goods = 14,075
That ´s not correct because the MAxdates > invoice date and the unitCost of 14,075 is the cost on 19.03.2015 and not just before my invoice date.
SQL 2012 :: Cost Threshold For Parallelism - Subtree Cost
Jul 3, 2014I right in thinking that if the estimated subtree cost is higher than the cost threshold for parallelism then it will use a parallel plan? If so, I've read the cost threshold is measured in minutes but is the subtree cost measured in something else, the mysterious cost number? And if so, how are the two compared?
View 9 Replies View RelatedBad Execution Plan
Aug 21, 2001I'm new to SQL server but familiar enough with databases to know this doesn't seem right.
Here's the situation:
I have a table with real estate property information. There are about 650,000 rows in it. I have a nonclustered non-unique index on the city where the property is located. There are about 40 unique values in this index.
I do a simple query like:
SELECT city,address from propinfo where city= 'CARLSBAD'. The query will return about 4,000 rows. The problem is that the execution plan that it chooses is to do a full table scan. I.E. Even though there is an index on City, it chooses to look through 650,000 rows rather than do an index seek. Something sounds inefficient here. BTW, this happens in both SQL 7 and SQL 2000. Can anyone explain why this happens? I've got to think that SQL Server is more efficient here.
Execution Plan
Feb 2, 2006Hello, I have been looking at the execution plan for a procedure call and the select, compute scalar, stream aggregates, constant scan, nested loops, asserts are all at 0% cost, the PK costs are 2% apart from a rogue 7% and a few 20%, tables scans are all at 23%. The query cost realtive to the batch is 100%. What does this all mean?
I have put non-clustered indexes on all the table attributes that are involved in the select statements but this has made no difference, i am guessing this is because my tables are not heavily populated and i may have seen a difference if i had thousands of entries in the tables the select statements acted on, is this assumption correct?
Does anyone else bother using the execution plan to tweak there DB or is it a negligible tool?
Jill
Execution Plan
Aug 29, 2007In sql server 2005 management studio where do I find the option to run the sql query in the query analyser and also show the execution plan?
At present I see the option under Query menu which is "Display estimated Execution plan" which only shows the plan but does not execute the query.
Thanks
Execution Plan
Feb 29, 2008Does anyone know of a good way to copy the execution plan when using "Include Actual Execution Plan"?
I often need to copy this and mail it.
I know I can use PrintScreen button, but I need a more efficient way to do this.
If I just could rightclick the execution plan and select "Copy" and get complete plan it would be great.
Mladen?
E 12°55'05.25"
N 56°04'39.16"
Execution Plan
Jul 20, 2005Which of the following does NOT cause the execution plan of a query to berecompiled ?- new column is added to a table accessed by a query OR- index used by a query has been dropped from the database OR- query perfoms a join to return data from multiple tables OR- significant amount of data in a table has been mofified
View 1 Replies View RelatedExecution Plan Of UDF
Jul 20, 2005Hi,I have a table-valued user defined function (UDF) my_fnc.The execution of statement "select * from my_fnc" takes much longertime than runnig the code inside my_fnc (with necessary changes).What can be the reason?How can I see an execution plan used for UDF?Thanks a lotMartin
View 1 Replies View RelatedGet Real XML Execution Plan
Jul 9, 2007Hi,I want to access the real execution plan via my webapplication after I have executed an SQL statement. I know how to get the estimated execution plan:1 cmd.CommandText = "SET SHOWPLAN_XML ON";2 cmd.ExecuteNonQuery();3 4 cmd.CommandText = myStatement;5 SqlDataReader dataReader = cmd.ExecuteReader();6 7 String plan = String.Empty;8 9 while (dataReader.Read()) {10 plan += dataReader.GetSqlString(0).ToString();11 }12 13 cmd.CommandText = "SET SHOWPLAN_XML OFF";14 cmd.ExecuteNonQuery();I want do compare the estimated costs with the real costs of the same statement. If I change code line 1 an 13 to "SET STATISTICS XML [ON|OFF]" the string "plan" will contain the result of the submitted SELECT statement, but I just need to get the plan and not the result itself. Thanks in Advance,Dominik
View 6 Replies View RelatedEstimated Execution Plan
Jul 28, 1999What does 'tablename. index... cost: 100%' mean when I use display estimated execution plan?
View 1 Replies View RelatedExecution Plan Analysis
Jul 9, 2003Hi,
I want to know how to analyze query execution plan for complex queries and what information is useful from that for improving the performance. I have gone through details in some sites like www.like sql-performance.com (http://www.sql-server-performance.com/query_execution_plan_analysis.asp), where it was more generic. I want more info regarding this.
Can any one tell about the resources for this or do you have any white papers or documents, which you can share with me.
Thanks in advance,
sekhar
Execution Plan Different For = And &<&> Operators
Jun 12, 2006Hi ,
when
operator = then index SEEK
operator <> then index SCAN
Is normal ?
Example
SELECT *
FROM dbo.Batch
WHERE (Status = 'Batch Completed')
(1 row(s) affected)
StmtText
---------------------------------------------------------------------------------------------------------------------------------
|--Bookmark Lookup(BOOKMARK:([Bmk1000]), OBJECT:([PriceAvisPr].[dbo].[Batch]))
|--Index Seek(OBJECT:([PriceAvisPr].[dbo].[Batch].[IX_Batch]), SEEK:([Batch].[Status]='Batch Completed') ORDERED FORWARD)
StmtText
---------------------------------------------------------------------------------
SELECT *
FROM dbo.Batch
WHERE (Status <> 'Batch Completed')
(1 row(s) affected)
StmtText
------------------------------------------------------------------------------------------------------------------------
|--Clustered Index Scan(OBJECT:([PriceAvisPr].[dbo].[Batch].[PK_Batch]), WHERE:([Batch].[Status]<>'Batch Completed'))
Execution Plan Degradation
Mar 24, 2008Hi all,
I am experiencing performance problems with one of my stored procedures. When the stored procedure is first compiled an executed, it behaves as expected (it usually takes 1 or 2 seconds to complete). But its performace it is degradated, so in 1 day, it usually takes 120 seconds to complete !!!. Once the stored procedure is compiled, its performance it is then the expected.
It is a complex stored procedure with two integer parameters with only one select, but composed by multiple views and sub-queries. We have been trying to break the query into small pieces using temporary tables but without success. The SQL Profiler shows an unusual number of reads when it goes wrong (more than a million reads).
I think the problem is in the execution plan. I know than compiling the stored procedure, the problem is fixed, but I do not know exactly when and why it starts to happen.
The stored procedure is running under the following configuration:
- Microsoft SQL Server Standard Edition (64-bit).
- Version: 9.00.1399.06
- RAM 16 MB
- 8 CPUs
Anyone has any ideas or possible solutions?
Thanks in advance,
Carlos.