We know that a query execution plan exists for Stored Procedures in the Procedure Cache.
What about Views? Does a view have a query execution plan? We know that a View is a virtual table and that virtual table is populated
when the view is induced but does it have a Query Execution Plan?
I have tried to find this info for Views in BOL but I cannot see it anywher in BOL.
I have 2 SQL databases which are the same and are giving me differentquery plans.select s.* from hlresults hinner join specimens s on s.specimen_tk = h.specimen_tkwhere s.site_tk = 9 and s.location in ('ABC','WIAD')and s.date_collected between '2/1/2003' and '2/3/2006'order by s.location, s.date_collectedBoth boxes have the same configuration, the only difference is that oneof them is a cluster.The Acluster box is taking twice as long to run the query.I have run statistics on both, and the cluster is still creating abitmap and running some parallelism which the other box is not.Also, the the first step, the A1 box estimates the rows returned to bearound 80K and the actual rows returned is about 40K - subtree cost =248. The Acluster box estimates 400K - subtree cost=533!After running statistics, how can it be so off?I've also reindexed to no avail . . .any insight would be very much appreciated. We just moved to this newsystem and I hate that the db is now slower -A1:affinity mask -2147483648 2147483647 0 0allow updates 0 1 0 0awe enabled 0 1 1 1c2 audit mode 0 1 0 0cost threshold for parallelism 0 32767 0 0Cross DB Ownership Chaining 0 1 0 0cursor threshold -1 2147483647 -1 -1default full-text language 0 2147483647 1033 1033default language 0 9999 0 0fill factor (%) 0 100 90 90index create memory (KB) 704 2147483647 0 0lightweight pooling 0 1 0 0locks 5000 2147483647 0 0max degree of parallelism 0 32 4 4max server memory (MB) 4 2147483647 14336 14336max text repl size (B) 0 2147483647 65536 65536max worker threads 32 32767 255 255media retention 0 365 0 0min memory per query (KB) 512 2147483647 1024 1024min server memory (MB) 0 2147483647 4096 4096nested triggers 0 1 0 0network packet size (B) 512 32767 4096 4096open objects 0 2147483647 0 0priority boost 0 1 0 0query governor cost limit 0 2147483647 0 0query wait (s) -1 2147483647 -1 -1recovery interval (min) 0 32767 0 0remote access 0 1 1 1remote login timeout (s) 0 2147483647 0 0remote proc trans 0 1 0 0remote query timeout (s) 0 2147483647 0 0scan for startup procs 0 1 1 1set working set size 0 1 0 0show advanced options 0 1 1 1two digit year cutoff 1753 9999 2049 2049user connections 0 32767 0 0user options 0 32767 0 0Acluster:affinity mask -2147483648 2147483647 0 0allow updates 0 1 0 0awe enabled 0 1 1 1c2 audit mode 0 1 0 0cost threshold for parallelism 0 32767 0 0Cross DB Ownership Chaining 0 1 0 0cursor threshold -1 2147483647 -1 -1default full-text language 0 2147483647 1033 1033default language 0 9999 0 0fill factor (%) 0 100 90 90index create memory (KB) 704 2147483647 0 0lightweight pooling 0 1 0 0locks 5000 2147483647 0 0max degree of parallelism 0 32 4 4max server memory (MB) 4 2147483647 14336 14336max text repl size (B) 0 2147483647 65536 65536max worker threads 32 32767 255 255media retention 0 365 0 0min memory per query (KB) 512 2147483647 1024 1024min server memory (MB) 0 2147483647 4095 4095nested triggers 0 1 0 0network packet size (B) 512 32767 4096 4096open objects 0 2147483647 0 0priority boost 0 1 0 0query governor cost limit 0 2147483647 0 0query wait (s) -1 2147483647 -1 -1recovery interval (min) 0 32767 0 0remote access 0 1 1 1remote login timeout (s) 0 2147483647 0 0remote proc trans 0 1 0 0remote query timeout (s) 0 2147483647 0 0scan for startup procs 0 1 1 1set working set size 0 1 0 0show advanced options 0 1 1 1two digit year cutoff 1753 9999 2049 2049user connections 0 32767 0 0user options 0 32767 0 0
View 1 Replies View RelatedGurus,
I'm trying to get an application finished that works like Query Analizer in
terms of returning query plans and statistics.
Problem the co-author is having:
>In using ADO to connect to SQL Server, I'm trying to retrieve multiple
>datasets AND statistics that are usually returned via the OnInfoMessage
>event. For those that are familiar with SQL Server, I need the results
>returned by the SET STATISTICS IO ON and SET STATISTICS PROFILE ON options.
>Anyone had any luck doing this before?
Can anyone shed any light on this please?
Thanks.
BTW if anyone wants to take a look at the tool so far - to see what I'm
delving into:
http://81.130.213.94/myforum/forum_posts.asp?TID=78&PN=1
Much Appreciated!!
Hi,We are trying to solve a real puzzle. We have a stored procedure thatexhibits *drastically* different execution times depending on how itsexecuted.When run from QA, it can take as little as 3 seconds. When it iscalled from an Excel vba application, it can take up to 180 seconds.Although, at other times, it can take as little as 20 seconds fromExcel.Here's a little background. The 180 second response time *usually*occurs after a data load into a table that is referenced by the storedprocedure.A check of DBCC show_statistics shows that the statistics DO getupdated after a large amount of data is loaded into the table.*** So, my first question is, does the updated statistics force arecompile of the stored procedure?Next, we checked syscacheobjects to see what was going on with theexecution plan for this stored procedure. What I expected to see wasONE execution plan for the stored procedure.This is not the case at all. What is happening is that TWO separateCOMPILED PLANs are being created, depending on whether the sp is runfrom QA or from Excel.In addition, there are several EXECUTABLE PLANs that correspond to thetwo COMPILED PLANs. Depending on *where* the sp is run, the usecountincreases for the various EXECUTABLE PLANS.To me, this does not make any sense! Why are there *multiple* compileand executable plans for the SAME sp?One theory we have is, that we need to call the sp with the dboqualifier, ie) EXEC dbo.spHas anyone seen this? I just want to get to the bottom of this andfind out why sometimes the query takes 180 seconds and other timesonly takes 3 seconds!!Please help.Thanks much
View 5 Replies View RelatedI have a stored procedure that suddenly started performing horribly.The query plan didn't look right to me, so I copy/pasted the code andran it (it's a single SELECT statement). That ran pretty well and useda query plan that made sense. Now, I know what you're all thinking...stored procedures have to optimize for variable parameters, etc.Here's what I've tried to fix the issue:1. Recompiled the stored procedure2. Created a new, but identical stored procedure3. Created the stored procedure with the RECOMPILE option4. Created the stored procedure with a hard-coded value instead ofaparameter5. Changed the stored procedure to use dynamic SQLIn every case, performance did not improve and the query plan remainedthe same (I could not easily confirm this with the dynamic SQLversion, but performance was still horrible).I am currently running UPDATE STATISTICS on all of the involvedtables, but that will take awhile.Any ideas?Thanks!-Tom.
View 10 Replies View RelatedAny way to invalidate cached query plans? I would rather target a specific query instead of invalidating all of them. Also any sql server setting that will cause cached query plans to invalidate even though only one character in the queries has changed?
exec sp_executesql N'select
cast(5 as int) as DisplaySequence,
mt.Description + '' '' + ct.Description as Source,
c.FirstName + '' '' + c.LastName as Name,
cus.CustomerNumber Code,
c.companyname as "Company Name",
a.Address1,
a.Address2,
[code]....
In this query we have seen (on some databases) simply changing ‘@CustomerId int',@CustomerId=1065’ too ‘@customerId int',@customerId=1065’ fixed the a speed problem….just changed the case on the Customer bind parameter. On other servers this has no effect.the server is using an old cached query plan, but don’t know for sure.
I think not. Microsoft says it is possible: one for parallel and one for serial execution. Don't believe that's possible for a stored procedure to change execution plans on the fly. Have an on-going problem with timeout occurring with an application and narrowed the culprit to a stored procedure. I couldn't find any obvious issues database wise, no locks, etc. so I recompiled (altered) the sproc without making any changes and the issue cleared for a couple days.
It happened again to day, and so I recompiled (altered) the sproc and it went away again. No code changes to both application (so they say) and stored procedure. I ran the below code snippet to check for sprocs with multiple cached plans and the offending one came up on a short list. So, my question is, Is it one sproc per query plan or can there be more than one. I understand the connection issues.
Code:
SELECT db_name(st.dbid) DBName,
object_schema_name(st.objectid, dbid) SchemaName,
object_name(st.objectid, dbid) StoredProcedure,
MAX(cp.usecounts) Execution_count,
st.text [Plan_Text]
INTO #TMP
[Code] .....
way to invalidate cached query plans? I would rather target a specific query instead of invalidating all of them.
Also do you know of any sql server setting that will cause cached query plans to invalidate even though only one character in the queries has changed?
exec sp_executesql N'select
cast(5 as int) as DisplaySequence,
mt.Description + '' '' + ct.Description as Source,
[Code].....
In this query we have seen (on some databases) simply changing ‘@CustomerId int',@CustomerId=1065’ too ‘@customerId int',@customerId=1065’ fixed the a speed problem….just changed the case on the Customer bind parameter. On other servers this has no effect. I’m thinking the server is using an old cached query plan, but don’t know for sure.
Try this script to see what queries are taking over a second.To get some real output, you need a long-running query. Here's one(estimated to take over an hour):PRINT GETDATE()select count_big(*)from sys.objects s1, sys.objects s2, sys.objects s3,sys.objects s4, sys.objects s5PRINT GETDATE()Output is:session_id elapsed task_alloc task_dealloc runningSqlText FullSqlTextquery_plan51 32847 0 0 select count_big(*) from sys.objects s1, sys.objects s2,sys.objects s3, sys.objects s4, sys.objects s5 SQL PlanClicking on SQL opens the full SQL batch as a .txt file, including the PRINTstatementsClicking on Plan allows you to see the .sqlplan file in MSSMS========Title: Using a VB Script to show long-running queries, complete with queryplans.Today (July 14th), I found a query running for hours on a development box.Rather than kill it, I decided to use this opportunity to develop a scriptto show long-running queries, so I could see what was going on. (ReferenceRoy Carlson's article for the idea.)This script generates a web page which shows long-running queries with thecurrently-executing SQL command, full SQL text, and .sqlplan files. The fullSQL query text and the sqlplan file are output to files in your tempdirectory. If you have SQL Management Studio installed on the localcomputer, you should be able to open the .sqlplan to see the query plan ofthe whole batch for any statement.'LongestRunningQueries.vbs'By Aaron W. West, 7/14/2006'Idea from:'http://www.sqlservercentral.com/columnists/rcarlson/scriptedserversnapshot.asp'Reference: Troubleshooting Performance Problems in SQL Server 2005'http://www.microsoft.com/technet/prodtechnol/sql/2005/tsprfprb.mspxSub Main()Const MinimumMilliseconds = 1000Dim srvnameIf WScript.Arguments.count 0 Thensrvname = WScript.Arguments(0)Elsesrvname = InputBox ( "Enter the server Name", "Server", ".", VbOk)If srvname = "" ThenMsgBox("Cancelled")Exit SubEnd IfEnd IfConst adOpenStatic = 3Const adLockOptimistic = 3Dim i' making the connection to your sql server' change yourservername to match your serverSet conn = CreateObject("ADODB.Connection")Set rs = CreateObject("ADODB.Recordset")' this is using the trusted connection if you use sql logins' add username and password, but I would then encrypt this' using Windows Script Encoderconn.Open "Provider=SQLOLEDB;Data Source=" & _srvname & ";Trusted_Connection=Yes;Initial Catalog=Master;"' The query goes heresql = "select " & vbCrLf & _" t1.session_id, " & vbCrLf & _" t2.total_elapsed_time AS elapsed, " & vbCrLf & _" -- t1.request_id, " & vbCrLf & _" t1.task_alloc, " & vbCrLf & _" t1.task_dealloc, " & vbCrLf & _" -- t2.sql_handle, " & vbCrLf & _" -- t2.statement_start_offset, " & vbCrLf & _" -- t2.statement_end_offset, " & vbCrLf & _" -- t2.plan_handle," & vbCrLf & _" substring(sql.text, statement_start_offset/2, " & vbCrLf & _" CASE WHEN statement_end_offset<1 THEN 8000 " & vbCrLf & _" ELSE (statement_end_offset-statement_start_offset)/2 " & vbCrLf & _" END) AS runningSqlText," & vbCrLf & _" sql.text as FullSqlText," & vbCrLf & _" p.query_plan " & vbCrLf & _"from (Select session_id, " & vbCrLf & _" request_id, " & vbCrLf & _" sum(internal_objects_alloc_page_count) as task_alloc, " &vbCrLf & _" sum (internal_objects_dealloc_page_count) as task_dealloc " &vbCrLf & _" from sys.dm_db_task_space_usage " & vbCrLf & _" group by session_id, request_id) as t1, " & vbCrLf & _" sys.dm_exec_requests as t2 " & vbCrLf & _"cross apply sys.dm_exec_sql_text(t2.sql_handle) AS sql " & vbCrLf & _"cross apply sys.dm_exec_query_plan(t2.plan_handle) AS p " & vbCrLf & _"where t1.session_id = t2.session_id and " & vbCrLf & _" (t1.request_id = t2.request_id) " & vbCrLf & _" AND total_elapsed_time " & MinimumMilliseconds & vbCrLf & _"order by t1.task_alloc DESC"rs.Open sql, conn, adOpenStatic, adLockOptimistic'rs.MoveFirstpg = "<html><head><title>Top consuming queries</title></head>" & vbCrLfpg = pg & "<table border=1>" & vbCrLfIf Not rs.EOF Thenpg = pg & "<tr>"For Each col In rs.Fieldspg = pg & "<th>" & col.Name & "</th>"c = c + 1Nextpg = pg & "</tr>"Elsepg = pg & "Query returned no results"End Ifcols = cdim filenamedim WshShellset WshShell = WScript.CreateObject("WScript.Shell")Set WshSysEnv = WshShell.Environment("PROCESS")temp = WshShell.ExpandEnvironmentStrings(WshSysEnv("TEMP")) & ""filename = temp & filenameDim fso, fSet fso = CreateObject("Scripting.FileSystemObject")i = 0Dim cDo Until rs.EOFi = i + 1pg = pg & "<tr>"For c = 0 to cols-3pg = pg & "<td>" & RTrim(rs(c)) & "</td>"Next'Output FullSQL and Plan Text to files, provide links to themfilename = "topplan-sql" & i & ".txt"Set f = fso.CreateTextFile(temp & filename, True, True)f.Write rs(cols-2)f.Closepg = pg & "<td><a href=""" & filename & """>SQL</a>"filename = "topplan" & i & ".sqlplan"Set f = fso.CreateTextFile(temp & filename, True, True)f.Write rs(cols-1)f.Closepg = pg & "<td><a href=""" & filename & """>Plan</a>"'We could open them immediately, eg:'WshShell.run temp & filenamers.MoveNextpg = pg & "</tr>"Looppg = pg & "</table>"filename = temp & "topplans.htm"Set f = fso.CreateTextFile(filename, True, True)f.Write pgf.CloseDim oIESET oIE = CreateObject("InternetExplorer.Application")oIE.Visible = TrueoIE.Navigate(filename)'Alternate method:'WshShell.run filename' cleaning uprs.Closeconn.CloseSet WshShell = NothingSet oIE = NothingSet f = NothingEnd SubMain
View 1 Replies View RelatedI compared view query plan with query plan if I run the same statementfrom view definition and get different results. View plan is moreexpensive and runs longer. View contains 4 inner joins, statisticsupdated for all tables. Any ideas?
View 10 Replies View RelatedI'd like to write a query that lists all the views for a particular database, can anyone help me out with this?
I've played around with the information_schema.views that the online books references, but I can't get it to return a list of the views? I know I can just
look at the views through enterprise manager, but I need to do this through a query. Many thanks
Fellow database developers,I would like to draw on your experience with views. I have a databasethat includes many views. Sometimes, views contains other views, andthose views in turn may contain views. In fact, I have some views inmy database that are a product of nested views of up to 6 levels deep!The reason we did this was.1. Object-oriented in nature. Makes it easy to work with them.2. Changing an underlying view (adding new fields, removing etc),automatically the higher up views inherit this new information. Thismake maintenance very easy.3. These nested views are only ever used for the reporting side of ourapplication, not for the day-to-day database use by the application.We use Crystal Reports and Crystal is smart enough (can't believe Ijust said that about Crystal) to only pull back the fields that arebeing accessed by the report. In other words, Crystal will issue aSelect field1, field2, field3 from ReportingView Where .... eventhough "ReportingView" contains a long list of fields.Problems I can see.1. Parent views generally use "Select * From childview". This meansthat we have to execute a "sp_refreshview" command against all viewswhenever child views are altered.2. Parent views return a lot of information that isn't necessarilyused.3. Makes it harder to track down exactly where the information iscoming from. You have to drill right through to the child view to seethe raw table joins etc.Does anyone have any comments on this database design? I would love tohear your opinions and tales from the trenches.Best regards,Rod.
View 15 Replies View RelatedDoes anyone know how to count rows of data from 1 table that meet one or two different criteria and then get the probability of occurance for that criteria ... as an output column?
Do I use 'Having' or temp tables or Views?
Here is my output for now. I am trying to solve for 'Prob' - everything else works on it's own.Craig
SELECT Wins_Lng/Trades_Lng as Prob
FROM Transactions
SELECT Count(Ticker) as Trades_Lng
FROM Transactions
WHERE TransType='C' AND DateDiff(day,BaseDate,GetDate())<=100 AND TransKind='B' (SELECT COUNT(Ticker)as Wins_Lng
FROM TransactionsWHERE Transkind='B' AND TransType='C' AND DateDiff(day,BaseDate,GetDate())<=100 AND Profit_Lng>=0)
I have a table which records the amount of times a user views a webpage
tblpageview
id
pagename
view_date
userid
I would like to have a query that returns the unique pagename and the amount of times that page has been viewed. I've had a go with count etc. but cant seem to get it. Anyone can help?
Here's the setup:
Client database has a complex view with eight nested subqueries used to return "dashboard" information. The application code uses NHibernate to call and filter the view with three parameters, one of which is the CustomerID.
A certain customer, (the biggest client), has more than ten times the number of records of the next largest customer.
Occasionally, the database reaches a state where when this particular customer tries to run the dashboard view, the application times out.
If I open up the view and re-save it, all is well again for a few days.
What gives?
Views are supposedly not pre-compiled, though I know that 2000 stores bits and pieces of query plans.
Any ideas on what causes this and what to do about it?
In SQL server 2008 how can I run the same query against each view in that database?
One database about 75 views.
Or even something like
Select 'yes' from view
Where shipping_status = 'delayed'
And return a list of view names so I know which views to query against.
I ran
Code:
select name from sysobjects where type = v
And got a list of my views. How can I now run my SQL statement against the list to see which views contain the info?
Ok, What I want to achieve is plain stuff, I want to join 2 views on a common key.It all works well with the SQL2000 Query Analyzer, but not trough ADO.NET or should I say my webapplication.With that I mean that my query return rows when executed from SQL2000 Query Analyzer, But not when used in my application or Executed from the Visual Studio Server Explorer.I have struggled with this one for several hours, I cant get this one right.So lets bring in the one who actually know what his doing View1: 1 select
2 cast((PS.RabattProsent/100.00)*PS.Pris AS decimal(11,2)) AS Rabatt
3 ,cast((PS.MVAProsent/100.00)*PS.Pris AS decimal(11,2)) AS MVA
4 ,cast(PS.Antall * ((PS.Pris*(100-PS.RabattProsent))/100)*((PS.MvaProsent/100.00)+1) AS decimal(11,2)) AS Belop
5 ,PS.*
6 ,K.Kunde_ID
7 FROM
8 tbl_ProduktSalg AS PS
9 INNER JOIN
10 tbl_Ordre AS O
11 ON
12 O.Ordre_ID = PS.Ordre_ID
13 INNER JOIN
14 tbl_Kunde AS K
15 ON
16 K.Kunde_ID = O.Kunde_IDView2: 1 SELECT
2 PS.Ordre_ID
3 ,SUM(cast((PS.RabattProsent/100.00)*PS.Pris AS decimal(11,2))) AS TotalRabatt
4 ,SUM(cast(PS.Antall * ((PS.Pris*(100-PS.RabattProsent))/100)*((PS.MvaProsent/100.00)+1) AS decimal(11,2))) AS TotalBelop
5 ,SUM(PS.Pris) AS TotalPris
6 ,SUM(cast((PS.MVAProsent/100.00)*PS.Pris AS decimal(11,2))) AS TotalMVA
7 FROM
8 tbl_ProduktSalg AS PS
9 GROUP BY
10 PS.Ordre_ID
MyQuery/SPRC: 1 create procedure %PROC% (@Kunde_ID int, @Ordre_ID int)
2 as
3 begin
4 SELECT
5 v_PSD.*
6 ,v_OTS.TotalRabatt
7 ,v_OTS.TotalBelop
8 ,v_OTS.TotalPris
9 ,v_OTS.TotalMVA
10 FROM
11 v_ProduktSalgDetaljer AS v_PSD
12 INNER JOIN
13 v_OrdreTotalSum AS v_OTS
14 ON
15 v_OTS.Ordre_ID = v_PSD.Ordre_ID
16 WHERE
17 v_PSD.Kunde_ID = @Kunde_ID
18 AND
19 v_PSD.Ordre_ID = @Ordre_ID
20
21 end
22
When working with databases containing myriad of huge tables, I am very much tempted to create categorized views on those tables in order to simplify and facilitate data query programming? Some developers I talk to say such views generally slow down query performance. Is this true?
Thanks.
Over the years I've read and experienced where joining more then 5 tables can lead to performance problems. This number can vary based upon the amount of data in each table, if and how indexes are used and the complexity of the query, but 5 has always been a good rule of thumb. Unfortunately I do not know what rule to apply in regards to joing views.
A developer has experienced timeout problems periodically when opening a view in EM or when running the code which makes-up the view. I decided to look at the view and noticed it references tables and views, which reference more views, which in turn reference other views. In all the initial view references 5 tables and 8 views directly and indirectly, with some of the views containing function calls. What are your thoughts on how many views and tables are too many when it comes to joins and query performance.
Thanks, Dave
I've just installed SQL Server 2005 Developer Edition, upgraded from SQL Server 2000, and have encountered a problem in trying to query against the System Catalogs.
I've tried SELECT * FROM sys.objects in addition to SELECT suser_name( role_principal_id ) FROM sys.server_role_members. In both cases I receive the following error: Invalid object name 'sys.objects' or 'sys.server_role_members' in the second example.
I changed the properties of the registration for my local db instance to use SQL authentication in lieu of Windows authentication. I used the sa login account to see if that made a difference, no go.
Can someone *please* tell me what I'm doing wrong here?
I would also like to know if it's possible to run a query confirming the user account I'm logged in to the system as.
Thanks!
Yes, I do know what this means and why the error is thrown but this is not my question.
I have two servers that are both running Windows Server 2003 and SQL Server 200 SP3. Below are the results from both servers using @@version
Sever 1 (BB)
Microsoft SQL Server 2000 - 8.00.760 (Intel X86)
Dec 17 2002 14:22:05
Copyright (c) 1988-2003 Microsoft Corporation
Developer Edition on Windows NT 5.2 (Build 3790: Service Pack 1)
Server 2 (Genesis)
Microsoft SQL Server 2000 - 8.00.760 (Intel X86)
Dec 17 2002 14:22:05
Copyright (c) 1988-2003 Microsoft Corporation
Developer Edition on Windows NT 5.2 (Build 3790: Service Pack 1)
These servers are identical or so it seems. I've got a real ugly query that uses views and a derived table to get results. The problem is the 256 limit message only comes up on one server and on the other (Genesis) the query runs fine. I get the error though it reads a 260 limit on a box with SP4 applied. I've also run the query on a box that is Windows 2003, sql2k and sp4 and the query runs but not on a similar server here. This is all very odd. Please note that the database structure, views, etc are all exactly the same as far as I know.
Any suggestions? There seems to be no pattern between versions of Windows and/or SP levels.
Hi,
I have come across this problem with SQL server both on 2000 and 2005. I am stating an example here.
I have two partitioned tables and a view on top of both tables as below:
create table [dbo].[Table_1]
(
[TableID] INTEGER PRIMARY KEY NONCLUSTERED
CHECK NOT FOR REPLICATION ([TableID] BETWEEN 1 AND 999),
[AnyOtherColumn] int NOT NULL ,
) ON [Primary]
GO
create table [dbo].[Table_2]
(
[TableID] INTEGER PRIMARY KEY NONCLUSTERED
CHECK NOT FOR REPLICATION ([TableID] BETWEEN 1000 AND 1999),
[AnyOtherColumn] int NOT NULL ,
) ON [Primary]
GO
create view TableView
as
select * from Table_1
union all
select * from Table_2
GO
Note the NOT FOR REPLICATION clause on the check constraint on the TableID column.
I then ran the query execution plan for the following query on both SQL server 2000 and 2005.
select * from TableView where TableID = 10
On both the versions the execution plan shows and Index seek on both the tables in the view. This means that my partitioning is not working. If I remove the primary key constraint from the TableID column, the same query on the view shows a table scan on all the underlying tables. This is even worse.
Next, create the same tables and views again, now without the NOT FOR REPLICATION clause on the check constraint as show below:
create table [dbo].[Table_1]
(
[TableID] INTEGER PRIMARY KEY NONCLUSTERED
CHECK ([TableID] BETWEEN 1 AND 999),
[AnyOtherColumn] int NOT NULL ,
) ON [Primary]
GO
create table [dbo].[Table_2]
(
[TableID] INTEGER PRIMARY KEY NONCLUSTERED
CHECK ([TableID] BETWEEN 1000 AND 1999),
[AnyOtherColumn] int NOT NULL ,
) ON [Primary]
GO
create view TableView
as
select * from Table_1
union all
select * from Table_2
GO
Now run the query execution plan for the same query again.
select * from TableView where TableID = 10
This time you would see that it does an index scan only on the first parititon table. This time it proves that the partitioning works.
I would like to know why does the NOT FOR REPLICATION clause in the check constraint make such a huge difference?
Is it a bug in SQL server?
Or am I missing any thing?
Any help appreciated.
Thanks
I've been using partitioned views in the past and used the check constraint in the source tables to make sure the only the table with the condition in the where clause on the view was used. In SQL Server 2012 this was working just fine (I had to do some tricks to suppress parameter sniffing, but it was working correct after doing that). Now I've been installing SQL Server 2014 Developer and used exactly the same logic and in the actual query plan it is still using the other tables. I've tried the following things to avoid this:
- OPTION (RECOMPILE)
- Using dynamic SQL to pass the parameter value as a static string to avoid sniffing.
To explain wat I'm doing is this:
1. I have 3 servers with the same source tables, the only difference in the tables is one column with the server name.
2. I've created a CHECK CONSTRAINT on the server name column on each server.
3. On one of the three server (in my case server 3) I've setup linked server connections to Server 1 and 2.
4. On Server 3 I've created a partioned view that is build up like this:
SELECT * FROM [server1].[database].[dbo].[table]
UNION ALL SELECT * FROM [server2].[database].[dbo].[table]
UNION ALL SELECT * FROM [server3].[database].[dbo].[table]5. To query the partioned view I use a query like this:
SELECT *
FROM [database].[dbo].[partioned_view_name]
WHERE [server_name] = 'Server2'
Now when I look at the execution plan on the 2014 environment it is still using all the servers instead of just Server2 like it should be. The strange thing is that SQL 2008 and 2012 are working just fine but 2014 seems not to use the correct plan.
I have a dynamic SQL query that uses various indexes and views.
When a user wants to filter records based on last one day, last one week, last 30 days ...etc.. i use the following code:
@date is an integer.
begindate is datetime format.
begindate > cast(((select dateadd(d,@Date,GETDATE()))) as varchar(20))
The above code slows my query performance by at least 400%!
Would it be faster to add a computed column to my table, using the suggested method in the link below?
[URL] ....
Then i could add an indexed view to improve performance, or can this be done another way?
Which is more efficient? One large view that joins >=10 tables, or a few smaller views that join only the tables needed for individual pages?
View 1 Replies View Relatedscript to get the list of views in a database, involving tables from other databases?I AM using SQL server 2014
View 2 Replies View RelatedI am trying to write some admin only procedures which will collect information to one of my development server from other production and development servers.
I have created linked servers to access these other servers on the development server. This development server is SQL Server 2000 EE. Other servers which I want to access are 2000 and 2005 (vaious editions)
E.g I have another development server called PRODTEST which is SQL Server 2005 and on the development server I have created a linked server pointing to PRODTEST called TESTLINKSRV. I want to access new object catalog view (as I do not want to use sysobjects)
When I run the following query
SELECT * FROM [TESTLINKSRV].[DBNAME].[sys].[objects]
I get following error,
OLE DB error trace [Non-interface error: OLE DB provider does not contain the table: ProviderName=' TESTLINKSRV ', TableName='" DBNAME "."sys"."objects"'].
Msg 7314, Level 16, State 1, Line 1
OLE DB provider ' TESTLINKSRV ' does not contain table '"DBNAME"."sys"."objects"'. The table either does not exist or the current user does not have permissions on that table.
So I try this query
SELECT * FROM [TESTLINKSRV].[DBNAME].[sys.objects]
and I get following error
Msg 208, Level 16, State 1, Line 1
Invalid object name TESTLINKSRV.DBNAME.sys.objects'.
So bottom line is how do I access catalog views on a 2005 server from a 2000 server using linked server?
I hope someone understands what I am trying to achieve. Please let me know what is it that I am doing wrong.
Thank you
Hello.
Newbie here. I've only been using SQL for about a year now and have some minor questions about sql objects that reference other objects.
We have some views which reference other views in the joins. I will call one the primary view and the one being referenced in the joins as the secondary view.
Recently we made changes to the secondary view.
After which the primary views which referenced it would not work because of this change and had to be 'refreshed' by using drop/create scripts which essentially just dropped it and recreated the exact same view. I do not recall the exact error message that was returned other than it seemed to suggest that it could no longer see the secondary view since it had been changed. Nothing in the primary view was changed in any way, just the secondary.
Some here where I work have suggested off hand that this was a recompile of the primary view because the contents of the secondary changed.
My questions are:
1. Exactly why did this happen and is there a proper name for it when it does?
2. The same problem does not seem to occur when we have stored procedures referencing views in the joins which had just been changed. Why is that?
Thanks for any help on the matter. I greatly appreciate it.
Hello,
to make a report easier I'm developing it using a view of joined views of joined views.
Is there any significant performance penalty as opposed to just having one big select?
Cheers.
I have two schematically identical databases on the same MS SQL 2000 server. The differences in the data are very slight. Here is my problem: the identical query has totally different execution plans on the different databases. One is (in my opinion) correct, the other causes the query to take 60 times as long. This is not an exaggeration, on the quick DB the query takes 3 seconds, on the other DB it takes 3 minutes. I have tried the following to help the optimizer pick a better execution plan on the slow db:
rebuild the indexes
dbcc indexdefrag
update statistics
I CAN put in a hint to cause the query to execute faster, but my employer now knows about the problem and he (and I) want to know WHY this is happening.
Any ideas would be greatly appreciated.
Thanks.
-Scott
SQL7: I have added a Maintenance Plan to backup to 4mm dat tape the master and msdb SQL databases as well as another database relative to our application called WISE. This works fine; however, it appears to always append to the media as opposed to overwriting (preferred). Any help would be appreciated.....
View 1 Replies View RelatedHi,
I am going to set up maintenance plans on all our SQL servers (7.0 and 2000). I have found several 'tutorials' on how to do this, but no one is describing the options in detail. Can you guys/gals please help me out? We have alot of small databases and some medium (1-2GB).
Thanks//Stefan
I am new to SQL Server 2000 & need ya all's help!!
I am trying to set up a database maintenance plan to back up databases & transactional logs. If I do a full backup once a week & a transactional backup every day...will I be safe enough to have enough backups to be able to restore to any point of time by restoring the full backup & the transactional logs upto that point?
In other words, I am asking what are the points to consider & what should be a decent backup plan? Do transactional logs take stored procedureal changes also?
Thanks for ur help,
Edward