I have a select statement (that joins 5 tables) and performs fine (when I execute with an additional 'and' statement that uses the 'like' keyword.)
select f1, f2, f3...f10 from table1, table2, .. ,table5 where table1.f3= table4.f4 and ... ... ... and table2.f7 = table1.f4 and table4.f4 like 'MYNAME%'
When I create a view with all of the statement except the last:
create view myview as select f1, f2, f3...f10 from table1, table2, .. ,table5 where table1.f3= table4.f4 and ... ... ... and table2.f7 = table1.f4
and then when I say
select * from myview where f4 like 'MYNAME%'
the performance tanks. The query plan completely changes and the resoponse time slows down 100+ times.
I know views are bad, but I am using PeopleSoft and I need to make this view work. Any ideas how?
I have a view on 5 tables. The first [tblOrder] 62000 records The second joined on the first [tblOrderRegel] 2140000 records The third joined on the second [tblAssortimentSamenstelling] 5800 records The fourth [tblArtikelVerpakking] 1650 records And the last also joined on the third [tblAssortiment] 30 records
When I use the next query SELECT * FROM [dbBIBSMonitor].[dbo].[vwOrderRegel_1] WHERE IDOrder in(SELECT IDOrder FROM [vwOrder] WHERE IDRelatie = 6) GO
It will take more than 60 seconds before the resuld is there
The sub select 'SELECT IDOrder FROM [vwOrder] WHERE IDRelatie = 6' returns a list of ID's. When I make the same select with this ID's instead of the sub select the result returns in 1 second
In the first select I have on all tables en index SCAN on the primairy Index with Hash Match/Inner Join to match.
In the second select I have on all tables en index SEEK on the primairy Index with Nested loop/Inner Join to match.
For the sub select 'SELECT IDOrder FROM [vwOrder] WHERE IDRelatie = 6' is not the primairy key used but an other Unique index Containing three columns. [IDOrder] (also the primairy Key), [IDStatus] (1, 2 or 3. 90% = 3), and a date field.
In the view on the subselect is an UNION of three selects. SELECT IDOrder, Date_1 From tblOrder WHERE IDStatus = 1 UNION SELECT IDOrder, Date_2 From tblOrder WHERE IDStatus = 2 UNION SELECT IDOrder, Date_2 From tblOrder WHERE IDStatus = 3
Thats the reason he usses the Unique Index
Is using this index the reason that he does not SEEK on the first table (also tblOrder) of the view in my select??? In other words: Does SQL-server can use only 1 index on a table for a SEEK?
I hope somebody can give me an answer on this complex story.
Thanks Jaap
By the way. I have already tried selects with a INNNER JOIN in stead of a sub query and also a corralated sub query.
Hi, I created a view on two huge tables. I tried to run a simple SELECT statement on this view and it took me several hours to obtain the result. How can I improve the performance of a view? The view should make use of the indexes built in both table, am I right? Thanks.
I have the same database on two different servers. One for production and one for testing. A view that I use runs in less than 2 seconds on the test system, but takes almost 2 minutes on the production server.
What I have noticed is on the test server the view will use an index. The production server ends up scanning a whole table. All indices are the same on both machines for the tables involved and I have updated the statistics. I even went through the process of creating a new table with its indices for the table that is being scanned. Both machines have had service pack 1 installed on them.
I have a view that has been working fine. The data is returned with a second or 2. But in the last 2 or 3 days it will periodically take so long to execute that it will timeout.
I am fairly new to SQL Server 2005, so I am not sure what to check. I am opening the view in Access using an ADP and also in Management Studio.
Also, there are only a couple of users and at the time we are experiencing problems, there really isn't anything going on. No one is trying to run a large query or anything like that.
CREATE VIEW VW_Emplacamentos WITH SCHEMABINDING AS SELECTA.CD_Linha -- This is the unique clustered field A.DT_Emplacamento, A.NR_CNPJ, A.CD_Municipio, A.VL_Potencia, A.VL_CapacidadeCarga, A.NR_QtdPax, A.NR_AnoFabricacao, A.NR_Chassi, A.SG_UF, A.CD_MarcaModelo, A.CD_Procedencia, A.CD_Combustivel, B.NM_Municipio, C.NM_Combustivel, D.NM_MarcaModelo, D.CD_Segmento, D.CD_Fabricante, E.NM_Segmento, F.NM_SubSegmento, G.NM_Fabricante
FROM dbo.TB_Emplacamentos AS A INNER JOIN dbo.TB_Municipio AS B ON A.CD_Municipio = B.CD_Municipio INNER JOIN dbo.TB_Combustivel AS C ON A.CD_Combustivel = C.CD_Combustivel INNER JOIN dbo.TB_ModeloVeiculo AS D ON A.CD_MarcaModelo = D.CD_MarcaModelo INNER JOIN dbo.TB_SegmentoVeiculo AS E ON D.CD_Segmento= E.CD_Segmento INNER JOIN dbo.TB_SubSegmentoVeiculo AS F ON D.CD_SubSegmento = F.CD_SubSegmento INNER JOIN dbo.TB_Fabricante AS G ON D.CD_Fabricante = G.CD_Fabricante
The following query is not getting perfomance. I don't what's going on.
SELECT COUNT(*) FROM VW_Emplacamentos WHERE DT_Emplacamento BETWEEN '20040301' AND '20040316' AND NM_Fabricante = 'VW'
I've created an compost index on the following sequece DT_Emplacamento,NM_Fabricante,NM_Segmento
I recently added several indexed views to a high traffic table (high volume of both inserts and selects) because I needed to have some complicated unique constraints involving columns that allow NULL.
While I didn't notice performance problems at first, it appears to be that the CPU on the SQL Server is getting pegged when more than 10 or 15 simultaneous inserts are happening on the table. This is a quad proc 3Ghz Xeon, so the fact the CPU is hitting 90%+ while doing 15 inserts a second doesn't make sense to me.
Very quickly the sproc that is being repeatedly called by some middle tier components is taking 30+ seconds to execute, eventually causing timeouts. This sproc is very simple. It does a few quick select statements (that take well under 100ms), and then does an insert into the table in question. That's it.
The only thing I can think of is that the overhead of 3 separate indexed views on the table, each of which contains a significant subset of the total rows in the table (550,000+ rows), is causing SQL Server to get swamped trying to keep the indexes up to date.
Does this seem like a possibility? I'm planning on temporarily removing those indexed views to see how it performs without them, although this is dangerous because it creates the potential for invalid data.
Hi all, first of all I shoud mention it that I have posted a similar question in Oracle forum and recieve enough oracle-related feedback and solution, here (http://www.dbforums.com/showthread.php?t=1609238).
Now I want to know if LIKE searches are awful (performance wise) in SQL Server too, do you recommand any solution to enhance it by some indexing twick? I want to avoid using MS index service (if I spell it correctly) as far as I could ;)
Note: We have a lot of LIKE '%abc%' queries at this system.
Greetings,I have 3 servers all running SQL Server 2000 - 8.00.818. Lets callthem parent, child1, and child 2.On parent, I create a view called item as follows:CREATE view Item asselect * from child1.dbchild1.dbo.Item union allselect * from child2.DBChild2.dbo.ItemOn child1 and child2, I have a table "item" with a column named "id"datatype uniqueidentifier (and many other columns). There is anon-clustered index created over column "id".When I connect to the parent server and select from the viewSelect id, col1, col2, …. From item where id =‘280A33E0-5B61-4194-B242-0E184C46BB59'The query is distributed to the children "correctly" (meaning itexecutes entirely (including the where clause) on the children serverand one row is returned to the parent).However, when I select based on a list of idsSelect id, col1, col2, …. From item where id in(‘280A33E0-5B61-4194-B242-0E184C46BB59',‘376FA839-B48A-4599-BC67-25C6820FE105')the plan shows that the entire contents of both children item tables(millions of rows each) are pulled from the children to the parent,and THEN the where criteria is applied.Oddly enough, if I put the list of id's I want into a temp tableselect * from #bv1id------------------------------------280A33E0-5B61-4194-B242-0E184C46BB59376FA839-B48A-4599-BC67-25C6820FE105and thenSelect id, col1, col2, …. From item where id in (select * from #bv1)the query executes with the where criteria applied on the childrendatabases saving millions of rows being copied back to the parentserver.So, I have a hack that works (using the temp table) for this case, butI really don't understand the root cause. After reading online books,in a way I am confused why ANY of the processing is done on thechildren servers. I quote:================================================Remote Query ExecutionSQL Server attempts to delegate as much of the evaluation of adistributed query to the SQL Command Provider as possible. An SQLquery that accesses only the remote tables stored in the provider'sdata source is extracted from the original distributed query andexecuted against the provider. This reduces the number of rowsreturned from the provider and allows the provider to use its indexesin evaluating the query.Considerations that affect how much of the original distributed querygets delegated to the SQL Command Provider include:•The dialect level supported by the SQL Command ProviderSQL Server delegates operations only if they are supported by thespecific dialect level. The dialect levels from highest to lowest are:SQL Server, SQL-92 Entry level, ODBC core, and Jet. The higher thedialect level, the more operations SQL Server can delegate to theprovider.Note The SQL Server dialect level is used when the providercorresponds to a SQL Server linked server.Each dialect level is a superset of the lower levels. Therefore, if anoperation is delegated to a particular level, then Queries involvingthe following are never delegated to a provider and are always it isalso delegated to all higher levels.evaluated locally:•bit•uniqueidentifier================================================This suggests to me that any query having where criteria applied to adatatype uniqueidentifier will have the where criteria applied AFTERdata is returned from the linked server.Any ideas on the root problem, and a better solution to get the queryand all the where criteria applied on the remoted linked server?Thanks,Bernie
I am running A View that INSERTS into #Temp Table - On Only Certain Days the INSERT Speed into #tempDB is so slow. Â Attached snapshot that shows after one minute so many few records are inserted - and it dosent happen every day somedays its very fast.Â
Hello Everyone,I have a very complex performance issue with our production database.Here's the scenario. We have a production webserver server and adevelopment web server. Both are running SQL Server 2000.I encounted various performance issues with the production server with aparticular query. It would take approximately 22 seconds to return 100rows, thats about 0.22 seconds per row. Note: I ran the query in singleuser mode. So I tested the query on the Development server by taking abackup (.dmp) of the database and moving it onto the dev server. I ranthe same query and found that it ran in less than a second.I took a look at the query execution plan and I found that they we'rethe exact same in both cases.Then I took a look at the various index's, and again I found nodifferences in the table indices.If both databases are identical, I'm assumeing that the issue is relatedto some external hardware issue like: disk space, memory etc. Or couldit be OS software related issues, like service packs, SQL Serverconfiguations etc.Here's what I've done to rule out some obvious hardware issues on theprod server:1. Moved all extraneous files to a secondary harddrive to free up spaceon the primary harddrive. There is 55gb's of free space on the disk.2. Applied SQL Server SP4 service packs3. Defragmented the primary harddrive4. Applied all Windows Server 2003 updatesHere is the prod servers system specs:2x Intel Xeon 2.67GHZTotal Physical Memory 2GB, Available Physical Memory 815MBWindows Server 2003 SE /w SP1Here is the dev serers system specs:2x Intel Xeon 2.80GHz2GB DDR2-SDRAMWindows Server 2003 SE /w SP1I'm not sure what else to do, the query performance is an order ofmagnitude difference and I can't explain it. To me its is a hardware oroperating system related issue.Any Ideas would help me greatly!Thanks,Brian T*** Sent via Developersdex http://www.developersdex.com ***
I am looking to create a constraint on a table that allows multiplenulls but all non-nulls must be unique.I found the following scripthttp://www.windowsitpro.com/Files/0.../Listing_01.txtthat works fine, but the following lineCREATE UNIQUE CLUSTERED INDEX idx1 ON v_multinulls(a)appears to use indexed views. I have run this on a version of SQLStandard edition and this line works fine. I was of the understandingthat you could only create indexed views on SQL Enterprise Edition?
Write a CREATE VIEW statement that defines a view named Invoice Basic that returns three columns: VendorName, InvoiceNumber, and InvoiceTotal. Then, write a SELECT statement that returns all of the columns in the view, sorted by VendorName, where the first letter of the vendor name is N, O, or P.
This is what I have so far,
CREATE VIEW InvoiceBasic AS SELECT VendorName, InvoiceNumber, InvoiceTotal From Vendors JOIN Invoices ON Vendors.VendorID = Invoices.VendorID
I created a query, which makes use of a temp table, and I need the results to be displayed in a View. Unfortunately, Views do not support temp tables, as far as I know, so I put my code in a stored procedure, with the hope I could call it from a View....
I 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?
Hello Everyone,I have a very complex performance issue with our production database.Here's the scenario. We have a production webserver server and adevelopment web server. Both are running SQL Server 2000.I encounted various performance issues with the production server witha particular query. It would take approximately 22 seconds to return100 rows, thats about 0.22 seconds per row. Note: I ran the query insingle user mode. So I tested the query on the Development server bytaking a backup (.dmp) of the database and moving it onto the devserver. I ran the same query and found that it ran in less than asecond.I took a look at the query execution plan and I found that they we'rethe exact same in both cases.Then I took a look at the various index's, and again I found nodifferences in the table indices.If both databases are identical, I'm assumeing that the issue isrelated to some external hardware issue like: disk space, memory etc.Or could it be OS software related issues, like service packs, SQLServer configuations etc.Here's what I've done to rule out some obvious hardware issues on theprod server:1. Moved all extraneous files to a secondary harddrive to free up spaceon the primary harddrive. There is 55gb's of free space on the disk.2. Applied SQL Server SP4 service packs3. Defragmented the primary harddrive4. Applied all Windows Server 2003 updatesHere is the prod servers system specs:2x Intel Xeon 2.67GHZTotal Physical Memory 2GB, Available Physical Memory 815MBWindows Server 2003 SE /w SP1Here is the dev serers system specs:2x Intel Xeon 2.80GHz2GB DDR2-SDRAMWindows Server 2003 SE /w SP1I'm not sure what else to do, the query performance is an order ofmagnitude difference and I can't explain it. To me its is a hardware oroperating systemrelated issue.Any Ideas would help me greatly!Thanks,Brian T
I had given one of our developers create view permissions, but he wants to also modify views that are not owned by him, they are owned by dbo.
I ran a profiler trace and determined that when he tries to modify a view using query designer in SQLem or right clicks in SQLem on the view and goes to properties, it is performing a ALTER VIEW. It does the same for dbo in a trace (an ALTER View). He gets a call failed and a permission error that he doesn't have create view permissions, object is owned by dbo, using both methods.
If it is doing an alter view how can I set permissions for that and why does it give a create view error when its really doing an alter view? Very confusing.
CREATE VIEW dbo.vwFeat AS SELECT dbo.Lk_Feat.Descr, dbo.Lk_Feat.Price, dbo.Lk_Feat.Code, dbo.SubFeat.SubNmbr FROM dbo.Lk_Feat INNER JOIN dbo.SubFeat ON dbo.Lk_Feat.Idf = dbo.SubFeat.Idt
When ever I open using SQL Entreprise manager to edit it by adding or removing a field i inserts Expr1,2.. and I don t want that. The result I get is:
SELECT dbo.Lk_Feat.Descr AS Expr1, dbo.Lk_Feat.Price AS Expr2, dbo.Lk_Feat.Code AS Expr3, dbo.SubFeat.SubNmbr AS Expr4 FROM dbo.Lk_Feat INNER JOIN dbo.SubFeat ON dbo.Lk_Feat.Idf = dbo.SubFeat.Idt
I don t want Entreprise manager to generate the Expr fields since I use the real fields in my application. Thanks for help
I was looking through our vendors views, searching for something Ineeded for our Datawarehouse and I came across something I do notunderstand: I found a view that lists data when I use it in t-sql,however when I try to use the statement when I modified the view (viaMS SQL Server Management Studio) I can not execute the statement. I getThe column prefix 'dbo.tbl_5001_NumericAudit' does not match with atable name or alias name used in the query.Upon closer inspection, I found two ON for the inner join, which I dontthink is correct.So, how can the view work, but not the SQL that defines the view?SQL Server 2000, up to date patches:SELECT dbo.tbl_5001_NumericAudit.aEventID,dbo.tbl_5001_NumericAudit.nParentEventID,dbo.tbl_5001_NumericAudit.nUserID,dbo.tbl_5001_NumericAudit.nColumnID,dbo.tbl_5001_NumericAudit.nKeyID,dbo.tbl_5001_NumericAudit.dChangeTime,CAST(dbo.tbl_5001_NumericAudit.vToValue ASnVarchar(512)) AS vToValue, dbo.tbl_5001_NumericAudit.nChangeMode,dbo.tbl_5001_NumericAudit.tChildEventText, CASEWHEN nConstraintType = 3 THEN 5 ELSE tblColumnMain.nDataType END ASnDataType,dbo.tbl_5001_NumericAudit.nID,CAST(dbo.tbl_5001_NumericAudit.vFromValue AS nVarchar(512)) ASvFromValueFROM dbo.tbl_5001_NumericAudit WITH (NOLOCK) LEFT OUTER JOINdbo.tblColumnMain WITH (NoLock) INNER JOIN---- Posters comment: here is the double ON--dbo.tblCustomField WITH (NoLock) ONdbo.tblColumnMain.aColumnID = dbo.tbl_5001_NumericAudit.nColumnID ONdbo.tbl_5001_NumericAudit.nColumnID =dbo.tblCustomField.nColumnID LEFT OUTER JOINdbo.tblConstraint WITH (NOLOCK) ONdbo.tblCustomField.nConstraintID = dbo.tblConstraint.aConstraintID AND(dbo.tblConstraint.nConstraintType = 4 ORdbo.tblConstraint.nConstraintType = 9 ORdbo.tblConstraint.nConstraintType = 3)UNION ALLSELECT aEventID, nParentEventID, nUserID, nColumnID, nKeyID,dChangeTime, CAST(CAST(vToValue AS decimal(19, 6)) AS nVarchar(512)) ASvToValue,nChangeMode, tChildEventText, 5 AS nDataType,nID, CAST(CAST(vFromValue AS decimal(19, 6)) AS nVarchar(512)) ASvFromValueFROM dbo.tbl_5001_FloatAudit WITH (NOLOCK)UNION ALLSELECT aEventID, nParentEventID, nUserID, nColumnID, nKeyID,dChangeTime, CAST(vToValue AS nVarchar(512)) AS vToValue, nChangeMode,tChildEventText, 2 AS nDataType, nID,CAST(vFromValue AS nVarchar(512)) AS vFromValueFROM dbo.tbl_5001_StringAudit WITH (NOLOCK)UNION ALLSELECT aEventID, nParentEventID, nUserID, nColumnID, nKeyID,dChangeTime, CONVERT(nVarchar(512), vToValue, 121) AS vToValue,nChangeMode,tChildEventText, 3 AS nDataType, nID,CONVERT(nVarchar(512), vFromValue, 121) AS vFromValueFROM dbo.tbl_5001_DateAudit WITH (NOLOCK)
A colleague of mine has a view that returns approx 100000 rows in about 60 seconds.
He wants to use the data returned from that view in an OLE DB Source component.
When he selects the view from the drop-down list of available tables then SSIS seems to hang without any data being returned (he waited for about 15 mins).
He then changed the OLE DB Source component to use a SQL statement and the SQL statement was: SELECT * FROM <viewname>
In this instance all the data was returned in approx 60 seconds (as expected).
This makes no sense. One would think that selecting a view from the drop-down and doing a SELECT *... from that view would be exactly the same. Evidently that isn't the case.
We have the same application installed on a few different environments with similar servers and similar hardward. The only difference is the versions of SQL and the colations. Is SQL 2005 a lot faster that SQL 2000? Could colation type make a big effect on performance? ScAndal
HiI want to insert 1000s of records into SQL Server 2005 Database with some manipulation. So that i put into the For Loop and inserting record.Inside the loop i am opening the connection and closing after use. The sample code is belowfor(int i=0;i<1000;i++){ sqlCmd.CommandText = "ProcName"; sqlCmd.Connection = sqlCon; sqlCmd.Connection.Open(): sqlCmd.ExecuteNonQuery(); sqlCmd.Connection.Close(); } What my Question is.. How is the Performance of this Code..?? Will is take time to get the Connection and Close the Connection in every itration?Or Shall I Open the Connection in Begining of the outside loop and close the connection at end of the Loop? will it increase the Performace?Please clarify me these question.. Thanks in advance.
this line 'select * from [viewUserLatestFee]' executes instantly (in Query Analiser) this line 'select * from [viewUserLatestFee] where orgID = 1' takes up to 30 seconds for 1000 rows (still in Query analiser)
can anyone please help - I seem to have ran out of ideas
I have a feeling people might be curious about the view so here it is:
We used a stored proc to pull totals from a database. Everything was fine until the table grew and started to time out. So we created a temp table to populate with a range of data and then pull the totals from there. Everything was fine until the table grew and started to time out. Any suggestion?
I am newly joined as SQL DBA. I want to check the Physical disk Performance. we have RAID 5 with 5+1 disks. I calculated NO Of IO's Per Disk. But how do we know what is actual limit of IO's per disk.
What's my best bet in getting better performance out of one of my database servers? Currently we have 1 set of Raid5 disks partitioned into 2 drives. This houses everything (system, database, and logs) If that server has 2 slots left for drives I was thinking of putting 2 mirrored drives and getting the logs off the main database space? (Make sense?) This is a vendored application so working with new indexes etc. isn't something I should do wo/ the vendor's interaction. Will what I describe above help?
We have SQL Server running on a dual processor Pentium 500mhz server. Our database is hit by about 300 users. 200 of those users are doing constant searches though a client table of about 250,000 records, which in turn is linked to a history table containing over 5,000,000 records. This is only the tip of the iceberg, we have many triggers, procedures, updates, etc. going in the background. The database has over 500 tables.
Keep in mind, these searches that are taking place can involve all kinds of fields: phone number, company name, fax number, first name, last name, status, wildcard searches, etc. So as you can imagine, the database is being hit with all kinds of funky requests to find records. I will be the first to admit that our developers (vendor) are not the best code writers, and we have a tough time getting them to optimize something they do not even understand themselves.
As I speak, our processor utilization is maxing out between 95 to 100 percent. I've done a lot of performance tuning and all of the problems lie in the searching. We've built, tested, rebuilt, re-tested each and every index. I even used the Profiler to filter what I could. It has improved, but our database is growing at a rate of 10 megs a day (already close to 3 gigs, not that huge). I think I've optimized my indexes as best as I can considering all the fields and possibilities available to users to search for records.
For a database that requires all of these different search criteria, what would be a more optimal server? We are looking to purchase something ASAP. I could really use help from someone in a similar situation. It seems odd, in mind, that a company of 300 people would need to rely on a quad server (four processor capability.).
HI I have 700 to 900 mb of production database , 2 gb of ram , 30 gb hard disk, My production machine is runnng very slow , i have check everything memory, page/sec, catch hit ratin , dbcc dbreindex but still it performance is not up to the mark. If i stop SQL SERVER & restart for few days machine works fine but after that again same thing it work very slow, what could be the reason if any one had any solution please suggest. Thanks Nil
