Hi, I have a question about nested views. Is there a way for the view not to place any locks on the underlying tables? I tried to re-write my views and its nested views with "with (nolock)" but when I view the enterprise manager, I still see exclusive and share lock on the tables. Any help would be appreciated. Thanks.
View 3 RepliesWhen running reports from data, is it faster using nested views approx 4 levels deep, or writing data to a temp tables then running the report?
View 3 Replies View RelatedI've been reading around that nested views can be quite inefficient because:
a) Using views in general involves some overheads (getting info from system tables etc.)
b) The optimiser doesn't do anything intelligent with them but just mixes all the joins from each of the nested views into one big, nasty join
If the only way to get the results I need involves writing this "big, nasty" join anyway, does it matter that I'm not putting it directly into a single view, but breaking it into components so that I can also access parts of the join for other purposes?
If the queries process lots of data, are the system overheads really that noticeable?
THANX!,
Angelos
I'm reading a book 'Professional SQL Server 2000 Programming' by RobertVieirathere is a recommendation: "stay away from building views based onviews"Why? What's so wrong with nested views?
View 2 Replies View RelatedI am working in a project where the business model is complex enoughthat many common retrieval functions become difficult to develop andmaintain in single query statements or functions.I have found the logic is easier to implement (and later modify whenthe code is no longer freshly remembered), by implementing theprocessing layers in nested views, and functions that callsub-functions (UDFs), not too unlike object based programming ornon-DBMS procedural languages. In some cases, the views and functionsare nested three deep.So far, from a design standpoint, this practice is working very well.Code that would be a recusive mess is reduced to two or three simplercode blocks. With the proper indexing and query structure, performanceseems to be satisfactory (time will tell).In MS SQL Server, is there anything which makes this practice unsound?Examples:CREATE VIEW vw2 AS SELECT * FROM tbl1 WHERE ...CREATE VIEW vw3 AS SELECT * FROM vw2 WHERE ...Application uses: SELECT * FROM vw3-or-CREATE FUNCTION udf2 AS SELECT * FROM tbl1 WHERE ...CREATE FUNCTION udf3 AS SELECT * FROM udf2 WHERE ...Application uses: SELECT udf3(param) AS value
View 5 Replies View RelatedThe code below is from a nested view, which I've read should be avoided. I've also noticed GETDATE() is used, which I believe causes GETDATE() to be executed for every record selected (correct me if I'm wrong). I'm also guessing a JOIN containing a UNION against a SELECT statement is not a good idea. What other problems do you notice?
SELECT trans.Entry_Code, trans.D_C, trans.ADP_Security_# ,
trans.TRID, trans.Batch_Code, trans.Last_Money,
null as Shares, Settle_date as Process_Date,
null as Closing_Price, trans.Dwnld_Date, trans.Acnt,
null as Mktval,
cast(Null as varchar(20)) as Cusip_#,
ACT.dbo.account.account_key AS account_key
FROM (SELECT * FROM ADPDBBOOK.dbo.YTD05B
WHERE (DATEDIFF(mm, Process_Date, GETDATE()) <= 15)
UNION
SELECT * FROM ADPDBBOOK.dbo.YTD06B) trans
INNER JOIN ACT_DATA.dbo.account
ON ACT_DATA.dbo.account.account_key = RIGHT(trans.Acnt, 5)
INNER JOIN tbl_Accounts_TransactionalData
ON trans.Acnt = tbl_Accounts_TransactionalData.Acnt
Thanks, Dave
Any easy way to find if there are any nested views existing in the database?...using SQL server 2014...
View 1 Replies View RelatedI have found that there is some very good information available inside of the dynamic management views related to Service Broker, however I have also found this to be problematic as by default only the dba's at my company had access to these views and it took me several days to get a login that could see them. Just a thought, but it would be nice if this data were available using a view that is more accessible.
View 3 Replies View RelatedAs im diving into my new DBA role and reading as much as I can, I am a little confused on DMV's and system tables.
I've been reading through the book "SQL Server 2005 Bible", which has been very helpful. I tend to use it in conjunction with BOL whenever I come across something I want to learn more.
Last Friday, I tinkered around with DMV's, which was really cool, but I ran into something today that confused me.
Basically, it was finding out the recovery model for all the DB's on the server. The code in the book was:
SELECT [name], recovery_model_desc
FROM sys.databases;
Which turned exactly what it says it will.
however, I am confused.
I initially thought I needed to specify something in the "[name]" section, but realized, that is not the case.
My question is, why is that?
How do I know when to use [] around something?
I found this article:
http://www.databasejournal.com/features/mssql/article.php/3587906
I have been reading it.
I guess I am just really young and raw to T-SQL to know when to use the language corectly.
Is it due to the fact that the rules or syntax is a little different when using system tables?
Hope that makes sense.
Thanks.
TCG
I have created a trigger on a table that get's too many updates so to analyze what records and what columns get updates I have coded a trigger that inserts into a table the record key and a flag on each column to let me know what is updates. Now that I am presenting the data to the developers I have been asked to provide the update / insert or delete statement
So on my trigger I have tried using dynamic management views but its returning the actual trigger code not the parent SQL Script that triggered it.
This is what I am using.
select@dDate as dDate, dest.[dbid], dest.[objectid], dest.[number], dest.[encrypted],
case when sder.[statement_start_offset] > 0 --the start of the active command is not at the beginning of the full command text
thencasesder.[statement_end_offset]
[Code] .....
I simply made my script task (or any other task) fail
In my package error handler i have a Exec SQL task - for Stored Proc
SP statement is set in following expression (works fine in design time):
"EXEC [dbo].[us_sp_Insert_STG_FEED_EVENT_LOG] @FEED_ID= " + (DT_WSTR,10) @[User::FEED_ID] + ", @FEED_EVENT_LOG_TYPE_ID = 3, @STARTED_ON = '"+(DT_WSTR,30)@[System::StartTime] +"', @ENDED_ON = NULL, @message = 'Package failed. ErrorCode: "+(DT_WSTR,10)@[System::ErrorCode]+" ErrorMsg: "+@[System::ErrorDescription]+"', @FILES_PROCESSED = '" + @[User::t_ProcessedFiles] + "', @PKG_EXECUTION_ID = '" + @[System::ExecutionInstanceGUID] + "'"
From progress:
Error: The Script returned a failure result.
Task SCR REIL Data failed
OnError - Task SQL Insert Error Msg
Error: A deadlock was detected while trying to lock variable "System::ErrorCode, System::ErrorDescription, System::ExecutionInstanceGUID, System::StartTime, User::FEED_ID, User::t_ProcessedFiles" for read access. A lock could not be acquired after 16 attempts and timed out.
Error: The expression ""EXEC [dbo].[us_sp_Insert_STG_FEED_EVENT_LOG] @FEED_ID= " + (DT_WSTR,10) @[User::FEED_ID] + ", @FEED_EVENT_LOG_TYPE_ID = 3, @STARTED_ON = '"+(DT_WSTR,30)@[System::StartTime] +"', @ENDED_ON = NULL, @message = 'Package failed. ErrorCode: "+(DT_WSTR,10)@[System::ErrorCode]+" ErrorMsg: "+@[System::ErrorDescription]+"', @FILES_PROCESSED = '" + @[User::t_ProcessedFiles] + "', @PKG_EXECUTION_ID = '" + @[System::ExecutionInstanceGUID] + "'"" on property "SqlStatementSource" cannot be evaluated. Modify the expression to be valid.
Warning: The Execution method succeeded, but the number of errors raised (4) reached the maximum allowed (1); resulting in failure. This occurs when the number of errors reaches the number specified in MaximumErrorCount. Change the MaximumErrorCount or fix the errors.
And how did I get 4 errors? - I only set my script task result to failure
Hi
We are facing an acute situation in our web-application. Technology is ASP.NEt/VB.NET, SQL Server 2000.
Consider a scenario in which User 1 is clicking on a button which calls a SQL stored procedure. This procedure selects Group A of records of Database Page1.
At the same time if User 2 also clicks the same button which calls same SQL stored procedure. This procedure selects Group B of records of Database Page1.
So, its the same Page1 but different sets of records. At this moment, both the calls have shared locked on the Page1 inside the procedure.
Now, in call 1, inside the procedure after selecting Group A of records, the next statement is and update to those records. As soon as update statement executes, SQL Server throws a deadlock exception as follows :
Transaction (Process ID 78) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction
We are able to understand why its happening. Its because, Group A and Group B of records are on the same Page1. But both the users have shared lock on the Page1. So, no one gets the exclusive lock in records for update, even though, the records are different.
How can I resolve this issue? How can I get lock on wanted rows instead of entire page?
Please advice. Thanks a bunch.
Pankaj
Hi,
I have set of 2 DTS packages, one of which calls the other by forming a command-line (dtexec) using a Execute Process task.
From the parent package-> Execute Process Task->
dtsexec /F etc... /<pkg variable> = "servername"
Each of the parent and the called package have a variable: "User::DWServerSQLInstance" which is mapped to the SQL server connection manager server name property using an expression. The outer package has the above variable and so does the inner called package (which gets assigned through the command line from the outerpackage call to inner)
I "sometimes" get the following error:
OnError,I4,TESTDOMAdministrator,ACDWAggregation,{A1F8E43F-15F1-4685-8C18-6866AB31E62B},{77B2F3C7-6756-46EB-8C01-D880598FB4B3},5/22/2006 5:10:28 PM,5/22/2006 5:10:28 PM,-1073659822,0x,The variable "User::DWServerSQLInstance" is already on the read list. A variable may only be added once to either the read lock list or the write lock list.
Help would be appreciated!
I have seen other posts on this but, not able to relate the solution to my scenario.
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 RelatedHi All,
I have seen a few other people have this error.
Package works fine when run from BIDS, DTExec, dtexecui. When I schedule it, It get these random errors. (See below)
The main culprit is a variable called "RecordsetFileDIR" which is set using an expression. (@[User::_ROOT] + "RecordSets\")
A number of other variables use this as part of their expression and as they all fail, pretty much everything dies.
I have installed SP1 (Not Beta) on server. Package uses config files to set the value of _ROOT.
The error does not always seem to be with this particular variable though. Always a variable that uses an expression but errors are random. Also, It will run 3 out of 10 times without a problem. I am the only person on the server at the time.
Any ideas?
Cheers,
Crispin
Error log:
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073659822,0x,The variable "User::RecordsetFileDIR" is already on the read list. A variable may only be added once to either the read lock list or the write lock list.
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073639420,0x,The expression for variable "rsHeaderFile" failed evaluation. There was an error in the expression.
OnError,,,DF_Header_Header,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636247,0x,Accessing variable "User::rsHeaderFile" failed with error code 0xC00470EA.
OnError,,,Move All Data,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636247,0x,Accessing variable "User::rsHeaderFile" failed with error code 0xC00470EA.
OnError,,,Load Open Batches and Process Files,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636247,0x,Accessing variable "User::rsHeaderFile" failed with error code 0xC00470EA.
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636247,0x,Accessing variable "User::rsHeaderFile" failed with error code 0xC00470EA.
OnError,,,DF_Header_Header,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636390,0x,The file name is not properly specified. Supply the path and name to the raw file either directly in the FileName property or by specifying a variable in the FileNameVariable property.
OnError,,,Move All Data,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636390,0x,The file name is not properly specified. Supply the path and name to the raw file either directly in the FileName property or by specifying a variable in the FileNameVariable property.
OnError,,,Load Open Batches and Process Files,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636390,0x,The file name is not properly specified. Supply the path and name to the raw file either directly in the FileName property or by specifying a variable in the FileNameVariable property.
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1071636390,0x,The file name is not properly specified. Supply the path and name to the raw file either directly in the FileName property or by specifying a variable in the FileNameVariable property.
OnError,,,DF_Header_Header,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073450901,0x,"component "rsHeader" (365)" failed validation and returned validation status "VS_ISBROKEN".
OnError,,,Move All Data,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073450901,0x,"component "rsHeader" (365)" failed validation and returned validation status "VS_ISBROKEN".
OnError,,,Load Open Batches and Process Files,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073450901,0x,"component "rsHeader" (365)" failed validation and returned validation status "VS_ISBROKEN".
OnError,,,POSBasketImport,,,10/05/2006 12:03:34,10/05/2006 12:03:34,-1073450901,0x,"component "rsHeader" (365)" failed validation and returned validation status "VS_ISBROKEN".
Hi,
I want to lock a table so others cannot lock it but able to read it inside transactions.
The coding I need is something like this: set implicit_transactions on begin transaction select * from table1 with (tablock, holdlock) update table2 set field1 = 'test' commit transaction commit transaction
I have tried the coding above, it won't prevent others from locking table1.
So, I changed the tablock to tablockx to prevent others from locking table1. But this will also prevent others from reading table1. So, how can I lock table1 so others cannot lock it but still able to read it?
Thank you for any help
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 RelatedHello.
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.
Is it possible to run both Sql Server Management Studio: Express and full blown side by side?
I am developing with the full blown product but would like to test Management Studio Express on the same box.
Is this possible?
Thanks
Eric
I have recently installed the SQL Server Management Studio Express but I do not find Management Tools in order to create scheduled backups and shrinking of the databases. I was under the impression that this should be included in the Management Studio. I use the SQL 2005 Express for smaller customers who run the SQL on a desktop unit. I need a way to backup the data to a server machine for backup purposes. I have uninstalled and reinstalled to no avail.
Hello There,I'm trying to create a view that has calculations dependent oncalculations, where the problem resides is that each time I make acalculation I must create an intermediate view so I can reference aprevious calculation.for example lets say I have my_table that has columns a & b. now I wanta view that has a & b, c = a + b, and d = c + 1.this is grossly simplified, the calculations I actually use are fairlycomplex and copying / pasting them is out of the question.so what I have is my_view_a which makes column c, and my my_view_finalwhich makes column d (however, in my real application I have 5 of theseviews, a/b/c/d/e/)is there anyway I can consolidate all these views into one? I wasthinking of using a stored procedure with temp tables or somethingalong those lines.I just which I can use the aliases that I create for c in d in onestep.any insight would be greatly appreciated.
View 5 Replies View RelatedHello everyone,I have a web project where users access a aspx page to view information stored in an SQL database.My client want that one user can access a row of information and see it, all other users shouldn't be able to view or update the same row?it means whenever a row of data is displayed by some user, this row should be locked even for beeing viewed by all other users, when this user close this page, this row will be available. ?I should do this in code behind or something in sql...How can I do that???
View 6 Replies View RelatedI remember there's a command you can type into SP . so no one else can see your SP even the SA. can anyone tell me what's the command is thanks!!
View 3 Replies View RelatedHello,
An application we are designing is behaving rather strangely. Basically, we
have a trigger on SQL 2000 on W2K Server watching for a record update. When
that happens a stored procedure gets executed which in turn spawns a VB that extracts that record, applies some rules to it, and writes a text file to disk. 9 out of 10 times, this program will cause a CPU spin, and it can't be killed from the Task Manager.
I did not write the VB app, I am writing the front end for the application in ColdFusion, but I need some ideas on what might be causing such behavior and how can the problem can be diagnosed. Thanks for any help!
Stas Newdel
Is it good practice to use WITH (NO LOCK) on SELECT statements, ie
SELECT * FROM MyTable WITH(NO LOCK)
Or does the SQL Server optimiser automatically use WITH (NO LOCK) ?
Hi,
i have a big problem , i work with sql 2000 on windows 2000.
When user do a select against my database sqlserver lock all the table and nonoe can work.
Haw can i change the isolation level for a ropw and for all the db.
Thanks.
Hello,
Wondering if anyone might have a guess about this.
I have a small 4 table DB. it's got several stored proc's and it's accessed through .NET to fill it in and get data from it.
It's been working just fine. But this morning, while it was doing its thing, I experimented with it by adding then deleting a View (through the View Wizard.)
Then later I started noticing that my .Net calls had slowed to a crawl (I hadn't made any code changes)and even making direct queries through Query Analyzer had slowed too.
My question is: being that there were no network issues, could the View create/delete have caused the DB to come to a halt or perhaps a table lock-up?
While I'm at it, is there anything that I can put in stored proc's or other places to prevent locking issues (if that's what happened here.)
I already use Begin/Commit Tran pairs.
And sorry if this post doesn't read like a SQL beginner, but believe me, I am.
Thanks for your advice!!
--PhB
Lets say i have a view.
vuTestingNoLocks
this view looks like this...
Create View vuTestingNoLocks as
SElect *
From dbo.Employees
inner Join dbo.EmployeeTerritories on EmployeeTerritories.EmployeeID = Employees.EmployeeID
If I select from this view using Select * From vuTestingNoLocks (NOLOCK)
Does the (nolock) command propegate down through the tables? Meaning will it scan tables that are locked still ignoring their locks?
I'm working with SQL Server Express, and I want to configure a named instance so that only the 'sa' user and a specified SQL Server user with a specified password have access. In particular, I'm trying to lock out BUILTINAdministrators. Furthermore, I need to be able to do this from a command-line, since I want to configure it in a script. Nothing I do seems to work.
I've attempted to use sqlcmd and the T-SQL call ALTER LOGIN [BUILTINAdministrators] DISABLE, but that returns the error "Cannot alter the login 'BUILTINAdministrators' because it does not exist or you do not have permission."
What I can (apparently) successfully do is run DENY CONTROL TO [BUILTINAdministrators]. This runs without reporting an error. However, after running it against the 'master' database and the specific database in my named instance I care about, I can still run the following:
sqlcmd -S (local)MyInstance -d MyDB -Q "select * from my_table"
and see the contents of my_table.
What do I need to do to restrict access exclusively to 'sa' and other SQL users I designate?
Hello.
I need to insert some records to an accounting table and calculate the balance after that. Thus, other users can be trying to do the same. How to lock the db and make the other users wait until the right moment? I'm using SqlDataSource to do that.
Thanks.
hi all iam working on a ticketing application i want to avoid two users to book the same ticket the requirement is as follows
1. the system should show all the available tickets which is not yet booked
2.when two users book the ticket at the same time time it should not allow the two persons to update at the same tme
the main aim is to avoid data concurency
how can i get this done
Hi,all:
This problem almost drives me crazy, hope I can get some hints from you guyz!!!
Ok, here is the situation:
I wanna only one users 2 modify the data(update) from my page each time, and if at the same time, there are some other users connecting my database through .aspx page, they can only browse the data until the first users finish updating.
It seems I need to implement locking the database, but I am not sure how I am gonna do that using asp.net!!!
Thanx in advance!