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There is necessary to create foreign key relationship between tables when we create database. I create a database and define references between the tables but could not define any physical relation between tables.
Please advice, I need your help
Cheers
Rajesh
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vnsraj wrote: There is necessary to create foreign key relationship between tables when we create database
If you ask if it is necessary, it isn't. An application can be built without using foreign keys. However I would recommend to use them since correctly used, they make the life a whole lot easier.
vnsraj wrote: I create a database and define references between the tables but could not define any physical relation between tables
The relation is not quite physical, but logical between two tables. In order ro use foreign key you must have primary key or unique key on master table and then you can define foreign key on the detail table. See examples A and B in CREATE TABLE[^]
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Hi,
We have a real time application that responds to user's input. The app uses SQL 2005 Express. We observed the following.
After the application idles for a while, the first access to the database takes a few seconds to process. Then, consecutive accesses are nuch faster. The SQL Standard does not show this poor performance after the idling.
Any comments and suggestions are welcome.
Best,
Jun
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Check the power savings settings on the machine that is running SQL Express. Maybe the disks have spun down during the idle period. That would cause a delay 
Does it have anything to do with the type of query that is being executed ? Large select (causing a full table scan), large insert,update or delete ?
Interesting problem.
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By idling, I meant the app does not use database for a while. The app is running at all times.
Best,
Jun
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There could be several reasons for this. Basically SQL Express uses the same codebase than Standard so most likely there are environment, configuration or schema (mainly indexes) differences.
One thing could be that buffer cache is loosing already read pages thus forcing physical reads next time. Is the memory usage defined as dynamic and are there other applications eating up the memory from the machine?
Also you could check from database options that the database is not closed automatically and if connection pooling is used at client side, that the lifetime for a connection in the pool is sufficient (connection string options).
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Hi,
interesting.
if everything else fails, I suggest you add a "keep kicking" thread (or a Windows.Forms.Timer) that periodically performs a simple query, just to keep the disk, the database, and everything else awake.
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
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I have noticed poor performance on SQL Express vs. Standard and the performance was cured by adding indexing that I thought were done by default.
Also, SQL server express can be run as a file based database. If there are no open connections the database engine would not be running and would go out of process. So the first access problem would occur quite frequently with this type of set-up too.
Really, just tweak stuff one at a time until something works.
Need custom software developed? I do C# development and consulting all over the United States.
If you don't ask questions the answers won't stand in your way.
Doing a job is like selecting a mule, you can't choose just the front half xor the back half so when you ask me to do a job don't expect me to do it half-assed.
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Firstly, Microsoft states that Windows isn't a supported platform for realtime applications. That's by design, it's an OS whose primary task is to support the user, not the realtime-tasks.
As for SQL Express, it usually needs to share resources, as opposed to the full version which usually has a server-environment of it's own.
"By default, AUTO_CLOSE is enabled for Microsoft SQL Server Desktop Engine (MSDE) and disabled on all other SQL Server editions." (source[^])
If you're only writing to the database, then consider setting up a proxy-application.
Hope this helps,
I are troll
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Hi,
I need to calculate a number of days from a given date which is on of the fields in the row to the present day and fill the value in a field of the same row. How can i do this please?
Thanks for your help
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Hi, I created a field called birthday in sql. It stored as date and time. ow i want to compare only the datepart of birthday with datepart of getdate()?
How it is possible?
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use following string
CONVERT(varchar, yourDateField, 111) in place of yourDateField
hope this helps
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What s mean by 111? can u explain?
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NO! That's horrible! Don't ever do that! 
I once had to maintain a program that did that, I changed it to use a proper date compare and it ran in a quarter of the time (ten minutes as opposed to forty minutes).
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where datepart(mm,bdate)=datepart(mm,getdate()) and datepart(dd,bdate)=datepart(dd,getdate())
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You could also test the difference between birthyear and current year and check using modulo 10 if the person having a big party
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Unless there's been space travel involved. 
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Aah, you're right, it would calculate the birthday too early. Perhaps Microsoft should include a new concept called slow modulo just for this purpose I think it would be interesting to read about it in SQL Server 2385 Books Online September edition.
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Hi,
if only someone would tell you to enter "SQL datepart" into Google, you might end up finding this[^].
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets
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Hi everybody,
I have configured a little SSIS-package that downloads files and synchronize them with my DB.
After deploying it, I run it from the IS Package Store (or whatever it is called). No problems, everything did nice.
Then I created a job for the SQL-Server-Agent in order to have my package run by schedule. But there it just did nothing...
I've worked out all the security-level-related articles like http://support.microsoft.com/?scid=kb%3Ben-us%3B918760&x=16&y=12[^], but nothing helped...
But after activating the option "Run under 32bit environment" (you can find it under "Steps / Execution Options") it worked fine.
Of course I'm glad about it, but I don't see why this option should be activated on a 32bit-system? What's the point? Of course I want it to run under 32bit, BECAUSE my system is 32bit
Any explanations?
Have a nice weekend!
Phil
I won’t not use no double negatives.
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What is a data type and how to retrieve it by c# coding?
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Hi,
This is not necessary to insert sound file in database, you can store your file name or path into the database table and store your file to the particular folder inside your projects.
Cheers
Raj
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