SET @propname = NULL -- can be Null or have wild card values
SELECT col1, col2, col3, propertyname FROM testtable where col1 = 1 and col2 = 2 and col3 = 3 and (@propname IS NULL OR propertyname LIKE @propname)
col1, col2, col3 are part of a clustered index
propertyname is a nonclustered index
This is the predicament. If the "@propname is NULL" is first in the OR statement then the query will use the clustered index for finding the record. If I put "@propname is NULL" last then it uses the propertyname index no matter what. So I either get full index scans if NULL is ever used on property names or I get consistent two second long searches on the clustered index. Any way to have the best of both worlds? Or do I have to divide up my query into more stored procedures?
1. A table has a PK of EmployeeID (non-clustered). The sql statement where clause uses something like "WHERE E.Action > 1 AND E.User = 1001 AND E.EmployeeID = 12345 Question: Will the PK index be used in determining the result set ?
2. A table has an index of EmployeeID + Company + State (clustered). The sql statement where clause is "Where EmployeeID = 1001". Question: Will the index be used in determining the result set ?
I was tuning a query testing out SARG with these two queries:
select col1 from table1 (nolock) where col1 like '#,%ABC%' or col1 like 'BC,%ABC%' select col1 from table1 (nolock) where col1 like '%ABC%'
I flushed out the cache, added an index to col1, then ran those two together. Provided below are the actual query plan and stat time:
Query 1: Query cost (relative to the batch): 0% select col1 from table1 (nolock) where col1 like '#,%ABC%' or col1 like 'BC,%ABC%' ---------------------------------------------------------------------------------------------------------------------------- SELECT Index Seek Cost:0% <------- [DB1].[dbo].[table1].[Idx..]
Cost: 100%
Query 2: Query cost (relative to the batch): 100% select col1 from table1 (nolock) where col1 like '%ABC%' ---------------------------------------------------------------------------------------------------------------------------- SELECT Index Scan Cost:0% <------- [DB1].[dbo].[table1].[Idx..]
Cost: 100%
------------------------------------------------STAT TIME----------------------------------------------------------- SQL Server parse and compile time: CPU time = 0 ms, elapsed time = 1 ms.
SQL Server Execution Times: CPU time = 0 ms, elapsed time = 1 ms. SQL Server parse and compile time: CPU time = 0 ms, elapsed time = 7 ms.
As expected, SARGable Query 1 did a nonclustered index seek and nonSARGable Query 2 did an index scan instead. According to the query plan, Query 1 consumed 0% relative to the batch whereas Query 2 is 100%. When I checked the CPU time, I was a bit confused because Query 1 showed CPU time of 938ms whereas Query 2 showed 515ms. I triple checked and every time I got similar results. I am sure I'm missing something, could someone please tell me what I'm missing? Thanks a bunch!
Hi guys,Got a problem now :( please help...now we got a project handling records saved in a table in a sql2000(will upgraded to 2005 soon) server. every month around a millionrecords will be inserted.now user raised a request, that is, once criterios are matched, theproject should do some backend handle, for example, ifSELECT colID, fieldC, fieldD FROM dataTable WHERE fieldA ='fieldA_valueB'returns some recordset, for each @fieldC, @fieldD we shall do someback-end trick, maybeUPDATE dataTable SET fieldE = 'fieldE_valueF' WHERE fieldC = @fieldCAND fieldD = @fieldDlet's say such a rule is named as rule01. Hope I'm expressing theproblem clearly?my questoin is, shall we do this in Database side, using triggers, orby informing our .net project to do it?1. since the records are coming around 1 millison per month, how can wehandling the performance issue?2. now the rules are still somewhat simple, seems at least we could doit by EXEC or SP_EXECUTESQL. but rules may turn quite complex, forexample, audit log, or more complex issues, shall we do it in .netprogram? but how can a trigger in SQL database informing a .netprogram, or webservice, or windows service? by executeing an executableconsole program?3. user may raise more and more rules, how could we provied a flexiblesolution? i mean we're trying to build it less hard-coded. seems in sqldatabase EXEC or SP_EXECUTESQL are still somewhat flexible, while in..net to do something like eval() in javascript or EXEC in sql server isa little bit troublesome. but, put all these bussiness logic in storedprocedure sounds a little bit weired.guys, hope i have made myself clear. any suggestion? Thanks very mcuhyours,athos.
I would like to build a report with nice functionalities like filter, sorting, drill-down, something like a PowerPivot Table, but with some layout/design/format capabilities. I would also want to publish the report, refresh it let´s say once a week, notify users when a new version is available, etc.
If I use PowerPivot, then I am not able to customized the report or to mix data from different sources in one table.
If I convert the cells of the PowerPivot table to workbook formulas I lose the filter, sorting, etc functionalities.
I still have to try using Reporting Services, but I think that always something is missing.
I have a datagrid in my file along with an Update Query.
My Update Query basically adds the numerical values in two columns together when the page is loaded. This means whenever the page is Refreshed the Update query is fired.
This is my Update Query (which is in an Stored Procedure):
UPDATE Rental SET TotalFee = ExtraFee + TotalFee WHERE DaysOverdue >= 0
I have declared my query in the 'Page_Load' part of the coding, because I want the query to run automatically. Not manually by a button.
My main question is that how can I get the query to run only once a day, no matter how many times the page is loaded.
SELECT ChannelCatID as '@type', ChannelID as 'Channel/@id', ChannelName as 'Channel/Name', RSSFeedURL as 'Channel/URL' FROM ChannelMaster FOR XML PATH('Item'), ROOT('DOC')
It gives me this result <DOC> -<Item Type="xyz"> --<Channel id="a"> ---<Name>aaaaa<Name/> ---<URL>aaaaa<URL/> --</Channel> -</Item> -<Item Type="xyz"> --<Channel id="b"> ---<Name>bbbb<Name/> ---<URL>bbbb<URL/> --</Channel> -</Item> -<Item Type="xyz"> --- -</Item> -<Item Type="xyz"> --- -</Item> ------ ------ ------ </DOC>
I want it this way :
all channels of Type xyz should come under singe <Item Type="xyz"> tag instead of seperate tags
what changes should i make, plezz help meout wit dis ??
I have a table with about 20,000 records. So, to minimise performance issues, i try to only retrieve the top 100 records. The databaset retrieved can be paged and sorted. Below is my code, but it's taking quite a while even to only load the 100 records. Any suggestions?Private Sub BindGrid() Dim connectionString As String = "MyConnectionString" Dim dbConnection As System.Data.IDbConnection = New System.Data.SqlClient.SqlConnection(connectionString) Dim queryString As String = "SELECT TOP 100 [Person].* FROM [Person] ORDER BY " & viewstate("sortField").ToString() & " " & viewstate("sortDirection").ToString() Dim dbCommand As System.Data.IDbCommand = New System.Data.SqlClient.SqlCommand dbCommand.CommandText = queryString dbCommand.Connection = dbConnection Dim dataAdapter As System.Data.IDbDataAdapter = New System.Data.SqlClient.SqlDataAdapter dataAdapter.SelectCommand = dbCommand Dim dataSet As System.Data.DataSet = New System.Data.DataSet dataAdapter.Fill(dataSet) Try DataGrid1.DataSource = dataSet DataGrid1.Databind() Catch e As Exception DataGrid1.CurrentPageIndex = 0 End TryEnd Sub
Requirement: I wanted to create another table based on the column values. For eg: I have to take the employee id and check for what value he has under owns column in the table. I take only 3 values and then these values should go to the newly created columns (owns1, owns2,owns3). if there is no value for any of these columns it should have null values loaded in them. The result of the modification should look like this:->
Note: eventhough employeeid 3 owns more than 3 things we only take 3 of what he owns and populate to above coloumns. In addition to it, the column OWNS will have more than 500 different values in them.
Its kind of urgent and if anyone knows how to , Can you please help me on this. Thanks a lot. -- Ragulan ;)
I am using a local variable to capture datetime and then select records from another table by making use of the above local variable result. But the query is running too slow when I use the local variable
declare @a smalldatetime select @a=last_run_time from job_status where job_des='sample'
SELECT * FROM History WHERE CHANGE_DATE> @a
Instead of the above select statement if I use the below statement it is returning results quickly. Can someone help me in tuning the above query. SELECT * FROM History WHERE CHANGE_DATE> '5/23/2008 6:22:00.000 AM '
History table has columns ( case number, change_date, change_desc). I have two indexes defined on the above table one is on case_number and the other on change_date.I tried using force index but still the query is running slow.
I want to make a sqldatasource to insert data ito a table with values from textfields page. I want to use the sqldatasource programically (not bind it to a formcontrol). I drag a sqldatasource from the toolbox to the design surface and start configuring the datasource. I spesify a custom sql statement, select the "Insert" tab and insert the table I want to store into the builder. Then I select the fields and the values (parameters from tue textfields. I test it with the "Execute query" button and the results is stored in the table. (everything seems ok) I press the "OK" button but both the "Next" and "Finish" buttons are dissabled, o I can not store the query. What is going wrong. Can someone please help me ? Tom Knardahl
I have a pivot table query I am running and wanted to find out if there was a way to pull in the dates like getdate() - 12 months, getdate() - 11 months, etc. instead of hard coding the dates.
Here is my query
SELECT Client, [4/1/2007 12:00:00 AM] AS Month1, [5/1/2007 12:00:00 AM] AS Month2, [6/1/2007 12:00:00 AM] AS Month3, [7/1/2007 12:00:00 AM] AS Month4, [8/1/2007 12:00:00 AM] AS Month5, [9/1/2007 12:00:00 AM] AS Month6, [10/1/2007 12:00:00 AM] AS Month7, [11/1/2007 12:00:00 AM] AS Month8, [12/1/2007 12:00:00 AM] AS Month9, [1/1/2008 12:00:00 AM] AS Month10, [2/1/2008 12:00:00 AM] AS Month11, [3/1/2008 12:00:00 AM] AS Month12, [4/1/2008 12:00:00 AM] AS Month13, Engineer FROM (SELECT Client, DollarsBilled, SlipDates, Engineer FROM dbo.MonthlyClientBillables) p PIVOT (SUM(DollarsBilled) FOR SlipDates IN ([4/1/2007 12:00:00 AM], [5/1/2007 12:00:00 AM], [6/1/2007 12:00:00 AM], [7/1/2007 12:00:00 AM], [8/1/2007 12:00:00 AM], [9/1/2007 12:00:00 AM], [10/1/2007 12:00:00 AM], [11/1/2007 12:00:00 AM], [12/1/2007 12:00:00 AM], [1/1/2008 12:00:00 AM], [2/1/2008 12:00:00 AM], [3/1/2008 12:00:00 AM], [4/1/2008 12:00:00 AM])) AS pvt
I.E. I WANT two columns C1# and C2#, where C1# contains data from 2015 and C2# contains data from previous year (2014). If 2015 data is not present, then C1# will contain data of 2014 and C2# will contain data of 2013.
SELECT a.AssetGuid, a.Name, a.LocationGuid FROM Asset a WHERE a.AssociationGuid IN ( SELECT ada.DataAssociationGuid FROM AssociationDataAssociation ada WHERE ada.AssociationGuid = '568B40AD-5133-4237-9F3C-F8EA9D472662')
takes 30-60 seconds to run on my machine, due to a clustered index scan on our an index on asset [about half a million rows]. For this particular association less than 50 rows are returned.
expanding the inner select into a list of guids the query runs instantly:
SELECT a.AssetGuid, a.Name, a.LocationGuid FROM Asset a WHERE a.AssociationGuid IN ( '0F9C1654-9FAC-45FC-9997-5EBDAD21A4B4', '52C616C0-C4C5-45F4-B691-7FA83462CA34', 'C95A6669-D6D1-460A-BC2F-C0F6756A234D')
It runs instantly because of doing a clustered index seek [on the same index as the previous query] instead of a scan. The index in question IX_Asset_AssociationGuid is a nonclustered index on Asset.AssociationGuid.
The tables involved:
Asset, represents an asset. Primary key is AssetGuid, there is an index/FK on Asset.AssociationGuid. The asset table has 28 columns or so... Association, kind of like a place, associations exist in a tree where one association can contain any number of child associations. Each association has a ParentAssociationGuid pointing to its parent. Only leaf associations contain assets. AssociationDataAssociation, a table consisting of two columns, AssociationGuid, DataAssociationGuid. This is a table used to quickly find leaf associations [DataAssociationGuid] beneath a particular association [AssociationGuid]. In the above case the inner select () returns 3 rows.
I'd include .sqlplan files or screenshots, but I don't see a way to attach them.
I understand I can specify to use the index manually [and this also runs instantly], but for such a simple query it is peculiar it is necesscary. This is the query with the index specified manually:
SELECT a.AssetGuid, a.Name, a.LocationGuid FROM Asset a WITH (INDEX (IX_Asset_AssociationGuid)) WHERE a.AssociationGuid IN ( SELECT ada.DataAssociationGuid FROM AssociationDataAssociation ada WHERE ada.AssociationGuid = '568B40AD-5133-4237-9F3C-F8EA9D472662')
To repeat/clarify my question, why might this not be doing a clustered index seek with the first query?
please explain the differences btween this logical & phisicall operations that we can see therir graphical icons in execution plan tab in Management Studio
I'm not the most knowledgable DBA, I've had to learn almost completely on my own, AND on a production server, because it's the only MS SQL Server I have access to.
Everything was fine before I took down the production server for maintenance. Someone suggested that I re-index my tables because I was having some performance issues with a particularly large table (it didn't help that table btw), so I did re-index.
Now, Everything works wonderfully, except for the performance issue mentioned AND one other thing that is going horribly wrong.
Here is the table:
create table ABMcontactlink ( classifier varchar(20) not null, /* Classification of contact. */ transmitter varchar(36) not null, contact integer not null, /* Link to ABMcontact (detail) table */ primary key (classifier,transmitter,contact), foreign key (contact) references ABMcontacts(identifier), group_name varchar(20) null,
last_modification_date datetime, /* Date/time record last touched */ last_modification_id varchar(40) /* Who last touched record */ )
go create index IndexABMcontactlink on ABMcontactlink(classifier,transmitter) go
create index CandidateABMcontactlink on ABMcontactlink(transmitter) go
As you can see, I have the primary key, which creates a clustered index, PK_ABMContactlink_Some Number, and two other indexes.
Now, this is a very busy production database, and most quick short queries benefit more from CandidateABMContactlink than from the other two indexes.
Unfortunately, in this production system, and this table, seconds count ALOT, so when I have roughly 3000-4000 quereies an hour pulling information from this table, I personally beleive I need to keep CandidateABMContactlink, and I'm not willing to find out on a production server.
** Now to the Problem at Hand **
I have one query that kicks off about 7 times a day, used to take less than 1 minute before the re-index. NOW it takes 30 Minutes. And it drags the system to a crawl.
I did some looking into it, and this query is using CandidateABMContactlink, and it takes 30 minutes. If it uses PK_Abmcontactlink it finishes in under 45 seconds.
Most queries are simple, "Select Column_names from abmcontacts where identifier in (select contact from abmcontactlink where transmitter = 'XXXXXX')"
This one is:
select * from ABMcontacts where ( (last_modification_date >= '2006-04-28 04:40:03' and last_modification_date <= '2006-05-09 16:41:14') and EXISTS(select contact from ABMcontactlink where contact = identifier and EXISTS(select transmitter_id from ABMtransmitter where transmitter_id = transmitter and (dealer = 'XXXX'))))
or (EXISTS(select contact from ABMcontactlink where (last_modification_date >= '2006-04-28 04:40:03' and last_modification_date <= '2006-05-09 16:41:14') and contact = identifier and EXISTS(select transmitter_id from ABMtransmitter where transmitter_id = transmitter and (dealer = 'XXXX'))))
I can't change the query, so how do I make it use the Index I want it to use without removing the index that it is using? (I know there are much better ways to write the above query, I'm not the culprit, if I could re-write it, I would)
Hi All, We have two production boxes running different ERP Apps on each boxes, We just added 2 more cpu's to one box and 1 cpu to other. The Currect CPUS config as stands is
Box 1 = 4 CPU's Box 2 = 2 CPU's
My boss whats some stats to see if performace was any better and if yes how much !!
Hi all, I have a problem in trying to find out why only one CPU in a 2 CPU H-T utilized. Using task manager, I can see 4 processors windows but only 1 actually utilized. I select +boost sql server and select all CPU for use. Queries and all other command ie dbcheck.. appear to use only single cpu. Any help would be nice. thanks Andrew
I want to keep track of the CPU utilization & number of users connected for each database on our production box. I chose to get the data from sysprocesses table from master database.
But I realised that for some reason the master..sysprocesses.CPU column stays static or just keeps on adding to existing values.
Is there any ways thru which I can clear this data ( cpu column in sysprocesses table) after I have captured it in a table ?
We have a SQL 7.0 Standard Server running on a Windows 2000 Servermachine with 2 800mhz Pentium III with 2GB memory. Our front end isAccess 97 and 2000 with most ADO connections for the scripts but someDAO for forms and reports. We recently "released" a new version ofthe "database" that caused a catastrophic event to start happeningwith our SQL server.Using PerfMon we monitored the CPU utilization on the server andnoticed that the CPU load would drop to 0 for approx 5-10 seconds andthen jump back up to our average 60-70% utilization. During thisdrop, there is NO disk activity no new connections being made, etc.We then took the process a step further and loaded a "stress" programthat put about 30% load on the server to start with. Then wemonitored each processes load. SQL Server process would drop to 0%while the stress process continued at 30%.The problem is that the SQL does absolutely NOTHING for 5-10 seconds.You cannot connect, any querys that are running stop, their is no diskactivity (logs, data drives), and you cannot even get sp_who2 to runfrom Query Analyser. We thought maybe blocking (we have built an"app" that monitors this), but we don't see any blocking before itlocks and nothing after it locks.Out of despiration we "rolled back" to our previous version to getpeople working again. After business hours, we have tried toduplicate the problem on machines (2 or 3 at a time) but cannot get itto duplicate the problem.The only experience we had previous to this was using DNS to resolvethe server name which caused a problem EXTREMELY familar to thisproblem. However, we have double checked every machine we have, andnone of them are using DNS to resolve.Any idea's would be most appreciated.Patrick Moore
I installed 4GB of memory and I have never seen SQL memory utilization go beyond 2GB. I have SQL server set up to use as much memory as it needs. Does anyone no if SQL server can make use of more than 2GB.
Ours is a SQL 7.0 Enterprise edition with NT 4.0 Enterprise Edition. SQL Server has been configured with the default, 'Dynamic memory Allocation'. The system has 4GB of RAM. This is a dedicated SQL Server machine. But SQL Server seems to use only 1.8GB RAM(Counter: Total Server Memory) The page faults seem to be a max. of 600 and an avg. of 100. The processor utilization has suddenly increased to 90%. Is there anything wrong with the way SQL server is using memory? Is is not true that SQL Server 7.0 Enterprise edition can use upto 3GB RAM in a 4GB system?
Are there any links that can help troubleshoot this problem?
After a fresh install of SQL 6.5 with SP5a(or without), the cpu is running at anywhere from 50%-80%. It is loaded on a PDC, but when I stop the sql service cpu utilization drops to 0-2%. When I start the sql service it's right back up there, does anyone have a suggestion as to how to fix this or why the service would be doing this?
I am getting high CPU utilization on the SQL Server process (>90%). However the overall utilization (NT -- entire box) always seems to be under 50%.
Can someone explain why this is happening. The server is a quad; the SQL server process seems to be using only two CPUs at a time (not the same ones all the time).
Lightweitht pooling has been turned on and the maximum worker thread size has been left at the default value (255).
How can I configure SQL options to spread the load across all four CPUs ??????
I have windows 2003 server with SQL Server installed on it for live calls billing but the CPU utilization is reaching the maximam and it's average above 60% which is causing lot of problems specially for the live environment. I have enough memory and free hard disk space is more than 40GB,
What do people think is normal for memory utilization? I know that's toobroad, so here are some basics.MS SQL Server 2000, Windows 2000 Server, 2GB RAMDb 1, size = 2.0 GBDb 2, size = 300MBDb 3, size = 50MBDb 4, size = 30MBDb 5, size = 30MBTypically 4-6 users, moderate usage 8-hrs/day. Performance has not slowed.Reboot on Sunday. sqlservr.exe in the Task Manager reports the followingSun 61MBMon 200MBTues 800MBWed 1,124MBThu 1,424MBFri 1,303MBI was getting srv 2020 errors when I had just 1 GB RAM: "The server wasunable to allocate from the system paged pool because the pool was empty."Then I did several updates to address this and got more RAM. I haven't seenthe errors since, but I haven't waited for them to happen: I'm rebootingevery week now. The memory numbers make me suspect SQL Server.Scratching my head. Not sure if my problem is gone, and this is normal SQLServer 2000 behavior, or if my problem is still lurking and I've only mutedit a bit.Any thoughts greatly appreciated.Tom
I have windows 2003 server with SQL Server installed on it for live calls billing but the CPU utilization is reaching the maximam and it's average above 60% which is causing lot of problems specially for the live environment. I have enough memory and free hard disk space is more than 40GB,
