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I second that.
As I recall it hasn't been mandatory to list target fields since mid 90's (depending on the db), but it sure helps (especially afterwards when little bit adding fields, renaming them and dropping a few )
The need to optimize rises from a bad design
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I need some pointers please. My friend Google overwhelms me when I ask "Distributed systems designs" or something similar.
We need to design a system with a 1000+ smallish and geographically distributed sites, each with a significant percentage of local, but volatile data. Think a distribution company with 1000+ outlets with "virtual stock" (thats voucher numbers which have real value). Each outlet has its own stock levels and customers but needs to know in realtime info of customers at other sites and global stock levels and goodness knows what else.
A somewhat reliable VPN is available to all sites.
Options:
1. I do not think this is a scenario where we occasionally update a central server with all local transactions (aggregate or even detailed), the data is too shared and needs to be near realtime for a significant proportion of the time.
2. Having one Hulk-sized setup centrally should work fine, but you cannot bring each site to a halt when there is a problem at the central server or the line to it has gone bad.
3. My idea is to use the one central hulk-sized server when all goes well, thereby avoiding all the distributed complexities (most of the time), but to switch over to a local DB when the line or central server goes bad, so that at least a significant proportion of transactions can continue.
Is Microsoft's Dryad any good here ?
Thanks in advance
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Seems like you have a headache coming...
Seriously, if not already done so, read about the concepts (for example from BOL) for:
- distributed transactions (two-phase commit and especialy DTS in Microsoft world)
- linked servers
- transactional replication
- service broker and message queues
These should give you info on somewhat different technologies for distributed systems at database level.
Hope this helps,
Mika
The need to optimize rises from a bad design
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Hi
First of all I have to say, that I'm in no way an SQL expert more likely an SQL dummy, so be warned.
I'm am currently building an InnoSetup installer hierarchy and as a part of that I have made a prerequisite downloader+installer for various Microsoft items - .NET Frameworks, Windows Installers, Internet Explorers, MDAC etc.
To detect the various components I use mostly registration keys, but as I played around with SQL Server 2005 Express I found out, that registration keys wasn't a good way detect it. Instead I tried creating an Ole object like this:
function SQLServerExpress2005Exist(): Boolean;
begin
Result := True;
try
SQLServer := CreateOleObject('SQLDMO.SQLServer');
except
if MsgBox(CustomMessage('SQLServerExpress2005Msg'), mbConfirmation, MB_YESNO or MB_DEFBUTTON2) = IDYES then Result := False;
end;
end; This method works when trying to detect an SQL Server 2005, but when I try using the same method on my computer with a running SQL Server 2008 Express, it doesn't work i.e. the code enters the except block.
What is the best way to detect an installed (not necessarily running) SQL Server 2008?
I'm in the high-fidelity first class traveling set.
And I think I need a Lear jet.
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try System.Data.Sql.SqlDataSourceEnumerator.Instance.GetDataSources();
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That looks like a .NET library and I can't use .NET in InnoSetup - not directly anyway and I can't be sure of which .NET version is on the target machine, and if it has one at all.
InnoSetup code is written in Pascal, so what I really need is a Pascal way of doing the check.
I'm in the high-fidelity first class traveling set.
And I think I need a Lear jet.
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I take some time on form & save it in datatable i.e. login time
then that time is in running condition as per system time,when user in working condition the current time is to be saved automatically after each 5 min.
is there any trigger fired on it within 5 min.each?
give be brief idea of that???
or any different way??????
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g_amol wrote: I take some time on form & save it in datatable
If you are using windows forms then look at adding a timer.
Bob
Ashfield Consultants Ltd
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can u give me a brief idea @ that???????
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As I said, add a timer to your form to fire every 5 minutes.
Bob
Ashfield Consultants Ltd
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you have to do that in c#, you are in the wrong forum!!!
like he said add a timer control in your form,
set interval propriety for 5 min
add event timer_tick and place your code inside
nelsonpaixao@yahoo.com.br
trying to help & get help
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hi!
can i change the column position of the existing table in sql server2000.
or
can i place my new column in first position on creation time.
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ahmad25 wrote: can i change the column position of the existing table in sql server2000.
Yes, but why? Columns should be referred to be name, not position, so the position is not relevant.
If you must do it, then go in the management studio, go to design table, make the chaneg but instead of saving look on the menu for something like 'Create Change Script'
I don't have sql server 2000 installed, so I can't remeber the extact location in the management studio, but you should be able to spot it.
ahmad25 wrote: can i place my new column in first position on creation time
Of course. Just put it first in your create script.
Bob
Ashfield Consultants Ltd
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THANKS A LOT BOB.
MY PROBLEM HAS BEEN SOLVED.
BUT I THINK I COULD NOT EXPLAIN MY SECOND PROBLEM.
i.e. I WANT TO ENTER OUR NEW COLUMN IN FIRST POSITION IF MY TABLE HAS ALREADY CREATED.
IF THIS POSSIBLE PLEASE HELP ME, OTHERWISE IT'S OK.
AGAIN THANKS.
BYE
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Regardless of position, if you go into the table designer, add the column where you want it (first, middle, anywhere) then you can generate ascript to do it, nut be warnd, on a big table it will take a while to run.
Bob
Ashfield Consultants Ltd
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forget that, let it be.
what do you want to achieve?
nelsonpaixao@yahoo.com.br
trying to help & get help
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For example,
SELECT * FROM sub_query
Can the sub_query contain a CTE?
I want to optimize sub_query by not changing anything outside sub_query.
Thanks.
professional
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Well, quicker than posting in a forum and waiting for a reply, why not try it and see?
Bob
Ashfield Consultants Ltd
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I've tried a lot , but I find no way.
professional
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Well, I would guess not as the WITH part of a CTE has to be the first statement in your sql.
Bob
Ashfield Consultants Ltd
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Hi,
I am going to desing a appicaion with is based on sending / recieveing sms, (Java and MySql),
The question is, wheather to handle sending / recieveing sms module in Java or MySql, pls advice some good
source/tools for creating technical desing for this type of applications.
Thanks Very much
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hi all ,i have 2 windows applications in c# connected with sql2005 database at the same time .these 2 windows applications insert a data in the database .i want that when one of these applications insert a row in database ,sqlserver2005 send a message or anything to the other application to inform it that a new row is inserted .it means that sql2005 send message to application.how i can do this?
Essampro
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Look at sql server broker notification, that should do it.
Bob
Ashfield Consultants Ltd
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think first in a LOCK protection (if you don´t have one).
i don´t know really how can i help you but, i suggest you to run/trigger a procedure to show the changed data since you logged out(meaning this user), i think is more important that the "on time update" info.
you can also create a log table, will be lot of aid there, to get who changed what and when!!!
do you need that kind of on time info, something like stock market info?
listen, you can make that on time info, or you can trigger a procedure after a short period of time, say 5min.
if i was you i would create a procedure to get the changed data since my last login/out and a procedure to get that on time info triggered each 5 min or like you said.
good luck
nelsonpaixao@yahoo.com.br
trying to help & get help
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You don't need to do all this, with SQL Server 2005 there is a thing called Broker Service Notification which does it for you - well almost - you do have to write a bit of code yourself
Bob
Ashfield Consultants Ltd
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