|
A comparison of the various editions of SQL Server is given here:
http://www.microsoft.com/Sqlserver/2005/en/us/compare-features.aspx[^]
There is no limit to the number of connections for SQL Express, other than the limits imposed by the restriction to a single CPU and 1GB of RAM.
As far as inserting into the same table from more than 1 client goes, SQL Express is no different from any other database. Depending on what your application is doing (insert only or are any reads or updates involved?), the transaction scope you use (do you insert each row in its own transaction, or do you block the whole lot into one big transaction?) and what isolation level you are using (the default - read committed - sounds as if it should be OK for your application if it's insert only), you may or may not see blocking occurring between the clients.
What do you do if SQL Express tops out and can't cope with the load? Well, one answer is: put your hand in your pocket and buy a full version of SQL Server. If you don't have the budget for that, you could either look to use one of the free databases that are available (MySQL, Firebird, PostgreSQL, SAPDB, there are loads of them around) or you could think laterally. Don't run all the scheduled jobs at noon, stagger them through the day. Or don't write directly into the main database, write each clients' log into its own staging area then have a single central job which comes round and collates it all together later. Think of it as a chance to get creative and flex your architectural design skills.
|
|
|
|
|
You might5 find this[^] article on BatchSize useful.
Henry Minute
Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”
|
|
|
|
|
Hello,
I have for example the following table
NICKNAME JOBNAME EQUIPNAME STARTTIME
SNB_A0_01_0719 051_A0_marbles_stress_AB_tie2vss post -FIB testing 2009-09-10 11:33:46.880
SNB_A0_01_0719 051_A0_marbles_stress_AB_tie2vss Post-FIB Testing Cabinet0 IS 2009-09-10 11:33:19.203
SNB_A0_01_0719 051_A0_marbles_stress_AB_tie2vss TESTING Cabinet 2009-09-10 11:34:13.233
SNB_A0_01_0720 051_A0_marbles_stress_AB_tie2vss post -FIB testing 2009-09-10 12:11:24.790
SNB_A0_01_0720 051_A0_marbles_stress_AB_tie2vss Post-FIB Testing Cabinet0 IS 2009-09-10 12:10:39.340
SNB_A0_01_0720 051_A0_marbles_stress_AB_tie2vss Pre-FIB Testing Cabinet0 IS 2009-09-10 07:58:20.937
SNB_A0_01_0720 051_A0_marbles_stress_AB_tie2vss TESTING Cabinet 2009-09-10 12:11:43.603
SNB_A0_01_0721 052_A0_marbles_stress_A_tie2vss Pre FIB Testing 2009-09-10 11:13:59.960
SNB_A0_01_0721 052_A0_marbles_stress_A_tie2vss Pre-FIB Testing Cabinet0 IS 2009-09-10 09:28:10.480
SNB_A0_01_0722 053_A0_marbles_stress_b_tie2vss Pre FIB Testing 2009-09-10 10:33:12.183
SNB_A0_01_0722 053_A0_marbles_stress_b_tie2vss Pre-FIB Testing Cabinet0 IS 2009-09-10 10:23:06.260
SNB_A1_00_0718 050_A1_DDR_Rx_Delay_pp Pre-FIB Testing Cabinet0 IS 2009-09-10 06:34:43.330
I need to choose distinct nicknames,jobnames and equipnames where the starttime is the biggest
for example for nickname SNB_A0_01_0719 i need only the 3rd row.
How can i do it?
|
|
|
|
|
Use a CTE with a Row_Number() partitioned over nickname, ordered by starttime desc with the appropriate where filter. From that select the record with row_number() = 3
|
|
|
|
|
Or:
SELECT * FROM TEST_TABLE
WHERE STARTTIME IN (SELECT MAX(STARTTIME)
FROM TEST_TABLE
GROUP BY NICKNAME, JOBNAME)
My advice is free, and you may get what you paid for.
modified on Friday, September 11, 2009 8:04 AM
|
|
|
|
|
select myDate
from myTable
where myDate > datediff(yyyy,now,myDate)=> 3)
I want to select date which is greater that now - 3 years(less than 3 yr.s old)
above query gives me following error:-
Msg 102, Level 15, State 1, Line 5
Incorrect syntax near '=' 
|
|
|
|
|
got it 
Posting it here if it might help anyone in future !!..
select myDate
from myTable
where datediff (yyyy,myDate ,getdate()) <= 3
|
|
|
|
|
select * from yourtablename
where
DateDiff(year, myDate, getdate()) >= 3
|
|
|
|
|
Hi,
I have installed a SQL Server Express 2005 instance with default name SQLExpress on a machine running Windows 2003 Server.
I have two databases on this instance with size 2GB and 1 GB(approximately) on this insance. These databases are accessed by a(Web based) .Net Application which is used by a maximum of 50 concurrent users.The application is a CRM for ticketing with Reports on the data punched by users.
My problem is that some times the SQL Server Express stops giving any connections. If I go and check the Database Engine service status in SQL Server Surface Area Configuration tool it shows the serive as running. As a hack I stop the service and start it again and SQL Server starts givgig connections again.
I have similar setup running in another location and that never gives such kind of problem.
Please help me with this problem as any downtime on Database is questioned from us.
thanks & regards,
Aman
|
|
|
|
|
I think this might be the cause of Unclosed connections. Always use
using block and also Before you leaving the block use connection.close(). 
And hey, you are using SQL Server Express 2005 in production environment..  This is weird. You need to keep in mind of the limitation of 4 GB Database size and 1 GB of RAM Usage.
There is as such no limitation of Concurrent Connection, but if you go on creating connections, it will soon run out of resources. Also you cant include 2 -4 GB ram because of Limitations. 
|
|
|
|
|
We currently have a system with a central database. (SQL server 2000).
Around the company we have several applications that read/write to the database. The company is distributed across several sites. Currently the database is at site A. There are two sites B and C that have leased lines to connect their networks to site A. From a computer point of view, it's all one big domain. Sites A, B and C are all in the same city (within about 15 miles of each other).
We are about to expand our network to a location in Dubai (Site D).
What is the best way to achieve the database connections for the application?
Would I be best to look at still having one central database and everything connecting to that (Via something like VPN or whatever), or should I be considering having a cloned/replicated database for the Dubai offices that is somehow synced up after hours? Do I need to be looking at the reliability of the internet connection in Dubai?
Can anyone with experience of this kind of thing offer any guidance?
I'm a software developer, and we have IT/network admins who will be doing the actual networking, but I need to be thinking about where/how I want my databases set-up.
Simon
|
|
|
|
|
This is a bit of a can of worms... If I was sitting down to design the architecture for a distrubuted application like this from scratch, i'd be very tempted to expose the data as services (web/wcf/whatever) and have applications at each site use these services.
However, it seems you're doing a straight database connection from each site to the central database - which is fine, but as you move further away from the database you have network latency and connectivity issues. Which is I think what you're asking about.
In terms of a solution - your suggestion of replicated database for Dubai is one way of solving the problem. You could also accept that the connection from any site to the database may slow down/fail and make your applications resilient to this (they should already be!). Perhaps think about hosting the database at a highly reliable site, with a fast connection - such as one of the big hosted data centres.
|
|
|
|
|
Thanks J4amieC,
With regards to data services yes I kind of agree here, given a choice from scratch I think I'd probably go down the same route, unfortunately this is an existing system that has grown beyond it's original intentions (as is so common with these kind of things) and I don't think a re-architecture like this is really an option - although it does have a nicely separated DAL so the option is there. We are actually building another system in a distributed style like this for exactly these kind of reasons.
Yes I am kind of asking about latency & connectivity etc. The application currently has an online and offline mode and falls back silently into offline mode if any database connection errors occur, and attempts to reconnect every 15 minutes, so the system is already fairly resilient to that kind of outage.
I'm also asking if there is anything else I should be aware of with the above approach.
Finally I'm interested if anyone has any experience with a replicated database. It's not something I've ever tried, and I'd have concerns that there would be problems, but as I understand it there are features like this that are transparently built into SQL server so I could just configure it and then carry on as if it was just a normal local database. I'd be concerned about how it would handle conflicts and locks.
Simon
|
|
|
|
|
Hi,
Just thinking out loud, mind you, so for what it is worth:
The main question is, what sort of data would you need at each site, at the same time, that must be in absolute real time sync?
The different sites of your company have been established for a reason, and I suppose it is not because all the people just won't fit into a single building. So I am guessing each site has its own customers, or vendors, or specialized work crew, or warehouse, or something.
That means that although each site will be organized with the same application(s), each will still mostly be working with unique data.
In other words, each site will be creating its own orders, deliveries, invoices, or whatever other business objects, that are specifically related to that site.
So adding site identifiers to all business objects in your database, should allow you to have each site run its own server/database/copy of the application. You can keep a central database at a single location that is updated every night (or whenever), through synchronization, or even simpler, using xml files. This central database could send certain common master data to each site's own database in turn, every night, hour, 15 minutes, etc. depending on requirements.
Usually even things like warehouse stock levels needn't be more up to date then 5 minutes.
This approach shouldn't need any kind of drastic measures, and might even offer greater flexibility for future development.
Cheers,
Johan
My advice is free, and you may get what you paid for.
|
|
|
|
|
Thanks Johan,
There's some good points in there. Like you say, the company is divided by sites for a reason, and yes large parts of the data is specifically for an individual site. I'm going to take a look at each table and decide how up to date it needs to be with respect to each site.
Thanks for the suggestions.
Simon
|
|
|
|
|
Hi, I am working on application that have following basic requirement
• Data(name) will be stored in Marathi (non-English) language
• During search user will type english charachter from keybord and the result will be shown in Marathi.
Does anyone have idea how to achieve this? Is it possible to store marathi DB in access?
Thanks in advance.
|
|
|
|
|
Have some google mojo[^] that should get you the answer on storing unicode data in a database.
As for typing english and searching marathi data, you would need to translate one language to the other. You cannot search for an orange in the apple orchard.
|
|
|
|
|
mighty mojo you have.
|
|
|
|
|
Why would this simple select error like this: sql 2008?
SELECT field1
FROM ADDRESS
where field1 != 'NULL'
"Error Msg 8114, Level 16, State 5, Line 1
Error converting data type varchar to numeric."
The real goal is to get this select to work but there are two fields causing me problems. The two fields commented out are generating the same error as above....how would I insert a cast into the below query for fields 4 and 5?
use dbname
Select field1 + ' ' + ISNULL(field2,'')
+ ' ' + ISNULL(field3,'')
--+ ' ' + ISNULL(field4,'')
--+ ' ' + ISNULL(field5,'')
as column_new from table1
Error converting data type varchar to numeric."
Regards,
Hulicat
|
|
|
|
|
Hulicat wrote: SELECT field1
FROM ADDRESS
where field1 != 'NULL'
select field1 from ADDRESS where field1 is not null
Hulicat wrote: how would I insert a cast into the below query for fields 4 and 5?
select cast(field5 as varchar)
|
|
|
|
|
Thanks for the reply.
I am having an issue inserting the cast into this statement for feilds 4, 5:
use dbname
Select field1 + ' ' + ISNULL(field2,'')
+ ' ' + ISNULL(field3,'')
--+ ' ' + ISNULL(field4,'')
--+ ' ' + ISNULL(field5,'')
as column_new from table1
Regards,
Hulicat
|
|
|
|
|
Hulicat wrote: I am having an issue inserting the cast into this statement for feilds 4, 5:
I already gave you that answer...
Here it is in total since you seem to have not understood what I was talking about...
use dbname
Select field1 + ' ' + ISNULL(field2,'')
+ ' ' + ISNULL(field3,'')
+ ' ' + cast(field4 as varchar)
+ ' ' + cast(field5 as varchar)
as column_new from table1
|
|
|
|
|
When you use the cast as per damians suggestion you need to define the size of the varchar as int
ISNULL(Cast Field4 as varchar(20)),'')
|
|
|
|
|
Thanks that was jamming me up....got it thanks.
Regards,
Hulicat
|
|
|
|
|
Mycroft Holmes wrote: you need to define the size of the varchar as int
Interesting... not in SQL-2005 you don't!!
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
