Here's my situation:
Both users are using the same Microsoft Access front end.
Both users have the same version of the SQL Server Native Client 10.0 ODBC driver.
Both users have the same version of Microsoft Office 2007 installed.
Both users are opening the same report with the same parameter values.
One takes 2 minutes, the other takes an hour.
The issue travels with the user, it happens regardless of which PC they log into on the network.
I checked the SQL passed to SQL Server and it is different. The one that runs quickly is standard T-SQL. The one that hangs is sending a parameterized query that has a terrible execution plan. I can't figure out what is causing it to send one query for one user and a different query for another user.
Since the issue travels with the user regardless of which PC they are on. This makes me think that it is some sort of obscure group policy setting or active directory setting that is part of the users account that is being replicated from PC to PC. Which probably means it's in the registry somewhere. But I am having a difficult time tracking down what that registry key is. Does anyone have any ideas?
Related
I'm developing a .NET desktop application with SQL Server as the database backend. One of the requirements of the application is that if a record status, for example, remains inactive for 30 days, there will be a reminder email sent to the user associated to that record.
This could be done pretty easily within the application, as long as it is started and running. However, assume that for a certain period of time, nobody starts up the application, the reminder email won't be sent, because nothing / nodody triggers the action.
How about creating a job in SQL Server which can monitors the records and sends emails as needed? Has anyone ever done that?
Thanks a lot!
Given the requirements of your task, I suggest that you create a console program (w/ C# or VB.NET) that checks for inactive (30 days) row condition and then generates the appropriate email notification message. Then run this program every hour or so (depending on the urgency involved in detecting an inactive row condition) using a SQL Server Agent Job.
The following image shows how the SQL Server Agent Jobs are displayed in the Object Explorer for SQL Server 2008 R2.
This SO entry covers some aspects on creating a console program that runs at certain times. The SQL Server Job Agent has several scheduling options that should facilitate your needs.
You might be reluctant to create a console program for this, but you are apt to find that doing so gives you options that are simply not easily implemented with a pure SQL Server based approach. Plus, you may have future needs that require similar processing that this approach provides.
I've been using Access to rapid-prototype a DB. Now I'd like to do a small group online test so I split the DB and placed the back-end on Azure SQL Server, then re-linked. It's incredibly slow and I've been researching solutions for days without positive results. My local environment is Win10, Office2016 64bit and internet connection is fast and stable.
I have tried different ODBC drivers, including the SQL Native Client v11.
I've disabled auto-tuning level on the NIC.
I've recreated all queries from access on the server.
I've made sure that Tracing in ODBC is off.
But I enabled tracing temporarily to see what was happening. If I opened the front-end, logged in (Small user table), and did something on the first form (Add 1 record with 3 sub-records...and really...nothing fancy or heavy at all and this only takes 1 minute) then closed the DB, I see that the Tracing log file is 1.5MB.
So I created an empty Access file and an ODBC link to only the User table (12 columns, 20 records), and then monitored the tracing log file again. Opening access doesn't add anything to the log file, but opening this one, linked table made the log file grow to 255kb. Opening this table in access took 5 seconds.
Access sent about 800 requests to the server for opening just this one small table. If I paste all the User table data into a text file, it's only 2kb. SO why is it so slow?
Any ideas on this, and specifically other suggestions to get this working faster?
Kind regards,
Well, the reason why using Azure is slower than running Access connected to a local instance of SQL server is because, well slow is slow!
I mean, if you going to travel 30 miles, you have a choice to walk, or to take a car.
So here is the question you need to know:
Why is walking slower than driving a car?
Answer: Because you are travelling at a slower speed!
So why is using Azure slower the using an instance of SQL server running on your local computer or local network?
Answer:
Because the connection speed to Azure is about 100 times slower!
The idea here that you not going to take into account the DIFFERENCE in connection speed is the issue here. It is a disservice to the reading public that may conclude that such a setup (Access front end on a pc to Azure instance of SQL server) is not a viable setup.
So the first issue here is to make a note of your connection speed to the back end database.
A typical office local area network has a speed of 100mbits, or today most are 1gig – even the el-cheapo routers you purchase at Best Buy are now rated at 1gig (1000 mbits).
However, your typical high speed internet is rated at about 5, or 10 mbits. So that is 100 times slower. (Actually 1000/5 = 200 times slower!!!).
That means if something NOW takes 3 seconds on your office network with Access and SQL server? Well then a WAN (over the internet), then you need to multiple the time by the change in your connection speed (this is so simple – yet it seems to escape all!). So, if you lucky, you might have a 5 mbits speed rating for your internet. That means you go
1000 / 5 = 200
You now take the 200 and multiple the existing delay you have of say 3 seconds and you get 600 seconds (that is 10 minutes if you are wondering!). So you going from 3 seconds to 10 minutes!
This kind of comparison in speed would be like walking into a sports shop to purchase a rubber boat to cross the Atlantic. So not taking into account the change in internet speed and wondering why things are slow is the issue here.
You can most certainly use Access to Azure, but you have to realize two simple concepts.
a connection and test with a connection that is 50-200 times slower than your LAN is a test that going to run 50 to 200 times slower! The failure to mention and take into considering the MASSIVE DIFFERENCE in your speed connection of your LAN compared to a WAN is the simple issue here.
opening a form bound to a large table of data is going to case performance issues.
I was sitting at the bus stop talking to a 90 year old granny lady. I asked her the following:
Have you ever used an instant teller?
She said, why yes, I use them all the time.
I then asked here don’t you think it would be bad to have the teller machine download all the peoples accounts while you wait and THEN ask you for your account number?
The old lady stated, of course, that would be silly. I type in my account pin and the machine ONLY downloads my account information – this is practical and obvious.
In other words that old lady realised that downloading a bunch of data BEFORE you the user even types in or does anything is a waste of bandwidth.
So you never want to launch a form bound to a table and THEN ask the user what record to work on. Why have Access download large numbers of records into a form and THEN ask the user or allow the user to navigate to the required record?
Even when using Google, it does not download the whole internet into your web browser page and you then go ctrl+f to search the contents of that web page.
The same concepts should be applied to Access applications. A design that asks for what to work on and then launches a form bound to a table with a "where" clause will thus fix this issue.
So if you have a form (and even a sub form) that displays a customer invoice, you would FIRST ASK FOR the invoice number, and then simply launch that form using a where clause that restricts the form to the ONE invoice!
Keep in mind that you can STILL use that invoice form bound to a table of 1 million rows and ONLY THE ONE record will be pulled down the network connection *if one used the where clause.
So a typical internet connection has adequate speed to run a browser, and also has MORE than adequate bandwidth speed to pull down a few records. Access often gets a bad rap for poor performance, but that is ONLY DUE to Access developers IGNORING the obvious advice that downloading tons of things that you don’t yet need into a form will run slow.
So web based applications, or even desktop applications written in vb.net perform well with SQL Azure running in the cloud over that MUCH slower internet connection because those applications don’t launch forms bound to large datasets WITHOUT FIRST simply allowing the user to request what they need to see and view.
As for Access and using SharePoint? That setup can be VERY fast, and in fact MUCH faster than SQL Azure, MySQL or any traditional database system because when you using SharePoint tables and Access, then Access automatic syncs a copy of the data local. This setup means your application will continue to run WITHOUT ANY internet connection. The instant the connection is restored, then the data sync can resume.
This means that if you have a table with 15,000 rows and run a report on that data the report can run and launch in an instant with SharePoint back end since a local copy of the data exists in the front end at ALL TIMES! So this setup is VERY well suited an off line mode or in cases that you have a poor and slow internet connections since you as noted always have local copy of the data – only when a record is changed does a sync occur, and that sync can occur independent of Access. So you change one record – and it starts syncing with SharePoint.
However for larger data sets that have to be updated, then SQL server is far better since you can execute a sql update on 10,000 rows and ZERO network traffic and transfer of data need occur to update those 10,000 rows when using SQL server (a pass through query) and when using SharePoint, the 10,000 rows WILL transfer over the network since the local copy requires the rows to be updated. So that massive advantage of using SharePoint for the database backend does not exist for applications that have to update lots of rows or do lots of row update types of data processing.
So the key concepts and take away here:
The high speed internet connection you have is often 10-200 times slower than your typical cheap office (local) network. So that means a 2 second operation will now take 10-200 times longer.
The Access application needs to be optimized to avoid things like loading too many records into a form. So building search forms etc. That FIRST ASK the user what they need to work on is a basic and simple requirement for all good developers and that includes Access developers.
Access and SharePoint can be the BEST option, and such a setup allows the application to run EVEN WHEN there is no internet connection at all. If table sizes are below say 10,000 rows, then this setup can often be ideal. However for applications that have to update lots of rows and for data processing heavy applications this setup is poor since updates to any rows will case data syncing to occur over the network. This setup is also the cheapest, since a single office 365 account with SharePoint support for Access can be had for $6 per month, and that $6 account allows up to 500 free users and those 500 users can even use their Gmail or non-Microsoft account for this setup. And such access applications that do fit within the bounds of SharePoint tables tend to need far less changes and optimizing then using SQL server over the internet.
With SQL server, use of views, pass-tough query and in some cases writing store procedures allows updates and code to run WITHOUT using ANY bandwidth. So one can send a single update query to the server that updates 10,000 rows of data – the only network cost will be the “tiny” amount of bandwidth to send that sql statement.
So while bound forms can be used with SQL Azure running in the cloud, one needs to build software like those do for the web, or vb.net in which they FIRST ask the user what account or customer to work on and THEN launch the UI to display that given data.
So in access, you build a search form say like this:
So at the end of the day, it is important to ignore posts here that suggests Access to SQL in the cloud is not viable. Access with proper designs will work rather well over typical internet connections to SQL server running on Azure.
In fact I seen people use Access to SQL over a 56k modem!
One has to adopt sensible designs in which the data pulled for a given task is restricted – this is a hall mark of all developers – the only issue is Access does NOT enforce this approach while most other developer tools don’t let you hang yourself with things like bound forms to large tables! It not that Access is slow, but Access is slow when you make poor design decisions.
Access to SharePoint can be a real winner – especially for poor bandwidth, spotty bandwidth and even when the connection is lost, the application will continue to run and run faster than 99% of the cases if you were running the same application with a SQL back end. There is a BIG caveat here since only certain types of applications will work well with SharePoint tables. For me to explain the why, how, and when such applications are better is beyond a simple post here, but one simply needs to be aware that SharePoint can be incredible solution, but not for all applications and SQL server can and will be better choice. This SharePoint “better” choice can only be determined on a case by case evaluation of the given type of application in question.
The problem is simply that Azure SQL Database is not very fast running with small DTUs (Database Transaction Units) compared to, say, an in-house instance of SQL Server hosted on even a moderate modern server.
I've checked it out too, and it requires extremely careful design of queries and filtering - far from what you normally can get away with - to obtain acceptable overall speed. On the other hand, this is a giving experience that will bring focus to potential bottlenecks you otherwise wouldn't encounter before it might be too late.
OK, so after almost a week of trying to get this to work (Access front-end to SQL Server back-end on Azure), I've come to the conclusion that it's not a viable solution.
I've tried SQL Server, and setup a Sharepoint 2016 server on Azure, which also failed.
What has worked is using a product from Bullzipp called MS Access to MySQL to convert the access tables, then adding a MySQL DB on the server and importing the file generated by Bullzip. The only thing to note here is that Bullzip doesn't like the newer access formats (it wants an MDB file) so go to Access, create a new, empty file, but make sure you set its file type to MDB. then import your tables across and run Bullzip.
It's now working a hell of a lot faster than the SQL Server, but I am getting some write conflicts in Access, so I just need to go through the code and do whatever I need to so I can avoid those messages.
Using Access as a front to Azure SQL tables is the worst solution. But, sometimes you have to do it. I have a client who is adamant that she wants to keep her Access database. When she hired her very first employee, it became clear she needed to SQL tables behind the screens.
This was a bit of a nightmare. However, after redesigning some terrible table structures, creating views and many procs, I've been able to do it. I use local tables in some cases, and refill by pulling from a stored proc and inserting into the local table. I use linked tables for basic data edits, and do explicit save records almost constantly.
I also have a first-load module that opens all forms, goes to the last record, back to the first record, and then hides the form until needed. The load limps along for about 3
My only remaining issue is now that Azure will close connections after idle time of (I think) 30 or more minutes -- or maybe it's when the laptop sleeps? That kills the app and it has to be closed and re-opened.
So I've had a Windows Workflow with persistence enabled and all has been well for a month now. This morning, things came crashing down with the error below. The problem is, a persistence store HAS been configured and working perfectly (in SQL Server). Absolutely nothing has changed. The database where the persistence information is stored is still there and healthy. We can find no problems with the database itself. No matter what we do, the list of available servers that should show up in the "Sql Server Store" dropdown remains empty.
It gets worse. The error isn't restricted to one server. It has happened organization-wide on several machines (we're using AppFabric with persistence enabled on multiple servers here). We've tried creating new databases on different servers running separate instances of SQL Server--same result. Our theory, such as it is, is that Microsoft pushed out some strange update via automatic updates overnight.
Clues, anyone? TIA
I have a very strange and complicated situation. I have data being erased from one of my SQL Server tables, and I am not sure by what application. I would like to be able to track this.
As I am sure you are wondering how I could find myself in this situation, here is some background. We have 2 servers, Web and Database running IIS6 and SQL Server 2005 respectively. They were setup by the previous developer who left the company without giving me any sort of introduction to the system so I am left "hunting" for everything.. I have been able to figure out most of the system on my own except for this, which remains a mystery. All I know for sure is this:
Data is being erased at a set time every day (I have setup a TRIGGER to capture this)
It is not a SQL Server Agent Job
It is not a Windows Scheduled Task
It is not a Windows Service
All database logins are done with the sa user so login history cannot help me... (again, I didn't set this up)
How the heck do I debug something like this? If anything, I want to know if this is coming from something running on the database server, or from a request from an outside source. Please help :-)
As you know the time it happens you should set up a SQL Profiler trace at that time to catch the statements being sent.
This will show you the SQL being sent, the spid of the connection, user name, application name sent by the connection and other useful info to track down the culprit.
In case the time that it happens is not convenient for you to do this you can script SQL traces (which is more lightweight than running the full GUI anyway)
Edit: Be careful when using it not to record so much information that you bog down the server. You can filter for activity on the database of interest for example.
I'm running Sql Server Management Studio 2008 on a decent machine. Even if it is the only thing open with no other connections to the database, anything that has to do with the Database Diagram or simple schema changes in a designer take up to 10 minutes to complete and SQL Management Studio is unresponsive during that time. The same SQL code takes less than a second. This entirely defeats the purpose of the designers and diagramers.
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System Information
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Operating System: Windows Vista™ Ultimate (6.0, Build 6001) Service Pack 1 (6001.vistasp1_gdr.080917-1612)
Processor: Intel(R) Core(TM)2 Quad CPU Q6700 # 2.66GHz (4 CPUs), ~2.7GHz
Memory: 6142MB RAM
Please tell me this isn't a WOW64 problem; if it is, I love MS, but step up your 64-bit support in development tools.
Is there anything I can do to get the performance anywhere near acceptable?
Edit:
I've got version 10.0.1600.22 of SQL Server Management Studio installed. Is this not the latest release? I'm sure I installed it from an MSDN CD and I pretty much rely on Windows Update these days. Is there any place I can quickly see what the latest release version number is for tools like this?
Edit:
Every time I go to open a database diagram I get the message "This database does not have one or more of the support objects required to use database diagramming. Do you wish to create them?" I say yes every time. Is this part of the problem? Also, if I press the copy icon, I get the message "Current thread must be set to single thread apartment (STA) mode before OLE calls can be made." Database corruption?
I'm running in a similar environment and not having that problem.
As with any performance problem, you'll have to analyze it a bit - just saying "it takes 10 minutes" give no information on the reason it takes so long, so no information you can use to solve the problem.
Here are some tools to play around with. I'd have mentioned them originally, but "play around" is all I've learned to do with them. I'd recommend you try learning a little about them, which I have not done. http://technet.microsoft.com is a good source on performance issues.
Start with Task Manager, believe it or not. It's been enhanced in Vista and Server 2008, and now has a better Performance tab, and a Services tab. Be sure to click "Show processes from all users", or you'll miss nasty things done by services.
The bottom of the Performance tab has a "Resource Monitor" button. Click it, watch it, learn what it can do for you.
The Resource Monitor is actually part of a larger "Reliability and Performance Monitor" tool in Administrative Tools. Try it. It even includes the new version of perfmon, which will be more useful when you have a better idea what counters to look at.
I will also suggest the Process Explorer and Process Monitor tools from Sysinternals. See http://technet.microsoft.com/en-us/sysinternals/default.aspx.
Do your simple schema changes possibly mean that you're reordering the columns of a table?
In that case, what SQL Management Studio does behind the scenes is create a new table, move all the data from the old table to the newly created table, and then drop the old table.
Thus, if you reorder columns on a table with lots of data, lots of indices or both, you CAN incur a massive amount of "reorganization" work without really realizing it.
Marc
Can you try connecting your SQL Management Studio to a different instance of SQL Server or, better, an instance on a remote machine (and try to make similar changes)?
Are there any entries in the System or Application Event Logs (or SQL logs for that matter)? Have you tried uninstalling and reinstalling SQL Server on your machine? What version of SQL Server (database) are you running?
Lastly, can you open the Activity Monitor successfully? Right click on the server (machine name) - top of the three in the object explorer window - and click on 'Activity Monitor'.
Do you have problems with other software on your machine or only with SQL Server & Management Studio?
When you open SSMS it attempts to validate itself with Microsoft. You can speed this process by performing the second of the recommendations at the following link.
http://www.sql-server-performance.com/faq/sql_server_management_studio_load_time_p1.aspx
Also, are you using the registered servers feature? If so SSMS will attempt to validate all of these.
It seems as though it was a network configuration problem. Never trust a developer (myself) to setup a haphazard domain at his office.
I had my DNS server on my computer pointed to my ISP's (default because the wireless router we're using provided by the ISP doesn't allow me to override the DNS server to my own) instead of my DNS server here, so I have to remember to configure it manually on each computer, which I forgot for this particular computer.
I only discovered it when I tried to connect for the first time to a remote SQL Server instance form this PC. It was trying to resolve to an actual sub-domain of mycompany.com instead of my DNS server's authority of COMPUTERNAME.corp.mycompany.com
I can't say why this was an issue for the designers in SQL Server but not anything else, but my only hypothesis is that when I established a connection to my own computer locally using the computer name instead of "." or "localhost", SQL queries executed immediately, knowing it was local, but the designers still waited for a timeout from the external IP address before trying the local one.
Whatever the explanation is, changing my DNS server for my network card on the local machine to my DNS server's IP made it all work very quickly.
I had a similar issue with mine. Turned out to be some interference with the biometrics login service running on my laptop. Disabled the service and now it works.