MS Access freezing - ms-access

My Microsoft Access 2007 is freezing on me. Could it be the 700 queries?
Yes, it's on a network, but only 2-3 people are accessing the backend at a time.
I have tried compact and repair, and also yelling at it. Nothing worked.

From my experience I can assure you that up to 15 persons working simultenously with back-end MDB should be fine with no visible freezing.
You can explore the following:
How big is your MDB? if it is too big consider splitting it to smaller parts and put all your historical and rarely accessed data into the separate file -- you can easily re-bind all the table in front-end to multiple back-end files.
Check your queries and VBA code. Use optimistic locks everywhere you can and avoid locking tables for reading purposes!
Check your network connectivity and hard drive throughput? Is your serving trying to perform a virus scan every time you update your MDB? Maybe an update is running?
If nothing helps -- try to install MS SQL Express, quickly upsize your tables and re-bind those to your front-end using ODBC connection -- you won't need to re-write your queries (as long as those are written in agnostic SQL, without DISTINCTROW etc).

It sounds like a locking issue. The Jet engine was not designed for multi-user access, and does not handle it very well at all. You should consider upgrading to SQL Server, which handles it much better. The Express version of SQL Server is free, and MS Access has an upsizing wizard that will do all the hard work for you.

Related

MS Access changing linked table to AWS MySQL Db slows down forms/reports

I am new to a new role at a company where they are using MS Access with a MySQL db which is running in server that's physically in our office behind our private network. I have been hired to develop an entire new application to bring the company up to modern standards. As we move features/modules to the new Angular/NodeJs App I am writing, users still need to utilize the UI provided by MS Access to the new production database that will be on AWS Lightsail.
However, when I change the configurations of Ms Access, OBDC connections to point to the AWS Lightsail MySQL Db, everything(reports especially) in the MS Access UI becomes slower than when it was being pointed to the MySQL Db here in office in-network.
I am going to the "Linked Table Manager" and changing the "Connection String".
Somewhere I read I should make sure SSLMODE is disabled to remove any performance issues.
DSN=AWS_Dev;DATABASE=ECSDataTables;PORT=3306;SERVER=IP_ADDRESS;SSLMODE=DISABLED;
I went through the normal "ODBC Data Source Administrator" in Windows and added the MySQL AWS host, user/pass as normal.
I have done extensive research and have found several sources, but none are really helping.
I have been asked not to spend too much time trying to fix/optimize anything in MS Access as my focus should be on the new application, but it's hard to believe that a simple switch of MySQL database can have such impact. In the new Angular/NodeJs application, everything runs very fast, so I know it's not the AWS MySQL db or anything.
Am I missing something, any configurations I should be doing in Ms Access? I have not used VB in about a decade, so I am hoping something can be done without the need of too much technical background in this matter.
Thank You.
Well, the issue is that your local area network (LAN) is about 10 times, or more faster then your internet connection.
Your low cost office network is very likely to be a 1 gig bit network. (100 base T is rare).
However, your internet high speed connection is likely say 10 mbits. So, you going from 1000 to 10 - that is 100 times slower. So, 3 seconds now becomes 300 seconds.
I mean, with such a slower connection speed, then no surprise should exist here.
What you can do is for any report that is a complex join of client side sql is convert the sql query to a server side view, link to that view. Now use that view as the base source for the report. And of course existing VBA filers that you always use (right???) to launch a report will now only pull the data it needs down the network pipe. Access reports (or forms) only pull down what you ask - not the whole table. So, any filter you have (use the where clause of the open report command) will be respected. So, you either have to pull less data, or simply find something with a similar speed rating as your local area network (and such high speed internet is rare).
The LAN vs WAN concept and speed issue is outlined in this article:
http://www.kallal.ca//Wan/Wans.html
While the above article is very old, the speed differences of the internet are about 10x faster today, but so is the local area that's gone from 100 baseT to 1 gig bit base.
So, things are slower because you are working with a VASTLY slower connection speed. Slower is slower!!!
Edit
While as noted, access will only pull what you ask, the case where access client does a poor job is sql queries that involve multiple tables - often the client will mess up what it sends server side. As noted, the solution in this case is to adopt views server side. This means you move the client side query that drives the report to a view, and link to that view. You not gain much performance for a single table query, but for any report based on complex (multi-table joins), then using a view will force the sql and "join work" to occur sql server side, and this can result in huge performance gains.
Well this is a case where limited knowledge just produces worst results than the expected ones.
Over the years top DBAs just "hate" Ms Access... they just see only problems,issues you name it ...the end sentence is "switch to a real Database engine".
Well this has created a faulty assumption that MsSQL, MySQL,Oracle, PostGreSQL and the rest database engines are somewhat a "magic pill"...you just switch the BE to one of the above DBE and all your problems will get resolved...just like that.
DBE --Database Engine (if you would like to call somewhat else feel free)
WRONG
Ms Access follows a different philosophy from the DBE and it does its job damn well given all its shortcoming and the major fact that is a file based DBE.
Switching to another DBE will give amazing performance IF and ONLY IF you respect the fact that you are not working with Access ....just don't treat e.g. MySQL as your file repository and DON'T just link the tables and expect everything to go well...
Want to keep blaming Access ...just switch over to another platform (.NET,PHP,Js , Java...make your pick) ...and do a small application that pulls ALL of your data in a single go like you do with Access . it will certainly crash or go Not responding...
So stop blaming Access ...start reading on how to make the most of two worlds and i am pretty sure that the results will amaze you....but again i must stress out that this is not a "magic pill" solution ...it involves a LOT of work ...planning,data manipulation,normalization,code changes and above all change of philosophy..
I would recommend starting the journey by picking this book : https://www.amazon.com/Microsoft-Access-Developers-Guide-Server/dp/0672319446 ( i don't want complains about its Old and MsSQL ...just read first and complain later)
Also take a look at an old benchmark alike video i made some years ago : https://www.linkedin.com/posts/tsgiannis_a-small-demo-of-connecting-ms-access-fe-to-activity-6392696633531858944-dsuU
Last but not least....years ago i was making some tests to see what the "magic pill" would do to my company's applications....the simplest test of all...
A simple table with few fields but with around 8 millions records...just display it
Access BE (local)--> It would run in 1-2 seconds...that's fast
Access BE (Network share)--> It would run in a few seconds...not so fast but it was usable
MSSQL BE (linked table)--> somethimes it get the results sometimes it wouldn't....slow...really slow ..like you make a coffee and go for a small walk.
MySQL BE (linked table)--> it never finished...timeout of "Not Responding"
PostGreSQL BE (linked table)--> it never finished...timeout of "Not Responding"
So stop blaming Access...start working and get amazed....

Classic ASP + MSAccess extremely slow on IIS7.5

I migrated my classic asp site from IIS6 to a much powerful server with Windows Server 2008 R2 and IIS7.5, but it actually runs even slower.
Every simple call to the MSAccess database is taking forever. Many times the request is dropped because of Session timeout (120 seconds).
Any idea what can cause the problem and how to solve it?
Thank You.
Before blaming Access and moving to SQL Server Express or another database, you need to make sure you know where the slowdown occurs.
From what you are motioning, it looks like at least some of the queries don't even work (IIS times out after 120s).
Access databases, especially if they are accessed locally by a handful of concurrent users, are fast.
Moving to another database may or may not solve the problem, but it will be probably be a lot more work than solving your issue with your current Access database.
That said, if your website needs to server lots of concurrent users (say more than 50 at a time) you may need to look into moving to a full database server like MySQL, SQL Server Express or PostgreSQL for instance.
A few things to make sure you double check:
Corrupted database. Make sure you use Compact and Repair regularly as a regular maintenance measure (make a backup first).
Incorrect filesystem rights.
Make sure the your IIS process has read/write rights to the folder where the database is located so that it is able to create the lock file (.ldb or .laccdb depending on whether you are using .mdb or the new .accdb database format).
A related issue is that the IIS process must be able to create temporary files in the temporary folder, for instance %SystemDrive%\Windows\ServiceProfiles\NetworkService\AppData\Local\Temp.
Bad queries. Open the database with Access and run the queries to check how long they really take and if they return any errors.
If there are data integrity issues, it could be that the query returns unexpected results that could have strange side-effect to the code in your asp page.
Check your IIS logs for errors. Also check the OS Event Log.
Make sure there are no other errors that could incorrectly cause the behaviour.
Make sure you profile your asp code to find out exactly which queries and parts of your code are slow and which are fine.
Once you have solved your issues. Improve performance by keeping the database open to avoid the lock file being create/deleted all the time (this can have a huge impact on performance).
A good reference with more detailed information on some of the topics above: Using Classic ASP with Microsoft Access Databases on IIS

Improving Performance in an MS Access Database

I have an MS Access 2003 Database with more than 60 tables and 120,000 records. This DB works on the network and it is split into a back end(BE) and a front end(FE). At most two or three users use this DB at the same time.
I want to improve the performance as it is currently quite slow. Which approach will improve performance - using FE/BE or putting the whole DB on a shared folder (without FE/BE) and then using it?
Under no circumstances should you run an unsplit MS Access app in a multiuser environment. If your app is slow, the article posted by vulkanino is a step on the way to making it faster. You should make sure that all you tables have suitable indexes, that queries use those indexes as far as possible, that forms are based on queries, not tables and that complex forms are carefully organised. For example, subform controls can be loaded with forms as required.
From my experience, none of your solutions will work well. You should use a sqlserver (full or express) as your backend. Then connect with odbc from the front-end. After that, look carefully at your indexes and try to move the most heavy query in storedprocedures or views in sqlserver. This will save your work on forms, reports and vba code.
Of course this scenario assumes a lot about your network (do you have a always on server pc?), about your work and purpose of your db.

Can I link an MS Access Application to Postgre SQL on a Linux Server? Can / Should I use ODBC?

I write MS Access / VB / SQL Applications, customized. One of my clients has a truly massive Access application I wrote them, and their number of active users have just expanded to over 15. Running into more data corruption issues, I am recommending they port to an SQL backend for stability. (Of course).
They would prefer to invest in a less expensive option and go with a Linux Server. I have used ODBC to hook an Access front to SQL backend plenty of times. But I have never touched Postgre.
I am looking for comprehensive detailed data on if this is a good strategic solution for a design plan, or if it is even a possibility. Perhaps there is an easier solution and I am barking up the wrong tree...
Yes, this is absolutely possible. I've not run into any major issues - the biggest I had was getting the Postgres boolean's to match up correctly - but it all depends on how you setup the ODBC connection and the actual application. I've found the ODBC connection stable and usable. If you really anticipate a larger number of users, you really ought to consider rewriting the whole app into something other than Access.
Overall, I'd definitely recommend Postgres as a backend via ODBC. Once you get used to a few of the differences, a lot of people really end up enjoying Postgres as a DB.

Is MS Access (JET) suitable for multiuser access?

I have a product designed to be a desktop product using MS Access file as a DB.
Now, some users need to install it in a few PCs (let's say 2 or 3) and SHARE the database.
I thought to place the MS Access file in a shared folder and access it from the PC, but... the JET Engine is designed for multiple user access?
Any tips or things to be aware of doing this?
EDIT:
The app is a .net one, using the database as storage (not using the database as frontend)
There is so much misinformation in the answers in this thread that I don't know where to start. I just spent 4 points in reputation voting down the answers with misleading and wrong information in them.
the Jet database engine (which is all that's involved here, as the OP clarified with an edit) is by default multi-user -- it was built from the ground up to be that way.
sharing a Jet data store is very reliable when the network is not substandard. This means not a WAN and not wireless, because the bandwidth has to be sufficient for Jet to maintain the LDB file (for multi-user locking), which means a ping by your local PC's instance of the Jet database engine once per second (with default settings), and because Jet can't recover from a dropped connection (which is quite common in a wireless environment).
the situation where Access falls down is when a front-end Access application MDB is shared (which is not the case for this poster). The reason it fails is because you're sharing things that can't be reliably shared and have no reason to be shared. Because of the way Access objects are stored in an MDB file (the entire Access project is stored in a single BLOB field in one record in one of the system tables), it's very prone to corruption if multiple users open it. In my estimation, sharing an Access front end (or an unsplit MDB with the tables and forms/reports/etc. all in one MDB) is the source for 99.99% of corruptions of Access/Jet files.
My basic answer to the OP's question is that, yes, Jet would be a great data store for an app of that size. However, if there's any possibility at all for the user population to grow above 25, then it might be better to start off from scratch with a database engine that is more robust at higher user populations.
It's perfectly feasible to do this; but you MUST split the database into a front end (with forms, queries, code) and a back end (data only). Every user has to have the front end on their own computer, linking to the shared back end.
It will be slow as Jet generates a ton of network traffic. Microsoft is also gradually deprecating Access as a development tool. Access 2007, for instance, has a far less sophisticated security model than Access 2003.
As a long time Access developer I am gradually moving away from Access.
Don't do it... the Jet database claims to be able to support multiple users, but it is incredibly easy to use the upsizing wizard to convert your Access file to a Sql Express database. That database file could EASILY become locked by a user or admin, and all of your users would be unable to use the database.
... and Sql Express is free. Your upgrade path from there to a full instance of Sql Server or some other commercial database is simple.
With 2 or 3 users on a reliable local network you should be fine, as long as you back the network drive up often.
Avoid any bit/bool fields in your tables - Jet has some nasty corruption issues with multiple access to them.
Also bear in mind that all locking in Access is optimistic: you will get dirty reads occasionally.
MS Access is designed for small office scenarios like this: non-critical light office use that you can set up with the minimum of programming.
Expect the data file to get corrupted every now and then - back up regularly.
The ACE/Jet engine is a great piece of software but, while it was designed to support multiple users, actually supporting multiple users in practise is not one of its strong points. The last straw for me is where then removed user level security (ULS) from the engine: I suppose I can imagine a simple database situation where all users will have the same privileges (i.e. admin access to all database objects) but IMO that is not supporting multiple users well, as compared with, say, MS SQL Server.
Yes, it supports access by multiple (that is, a small, workgroup-sized, number) of users over a network file share. However, the file share architecture is simply not ideal for supporting simultaneous writing to a file by multiple users. A client/server database system (SQL Server, etc.) generally provides better performance, security, and reliability.
As a sysadmin, please don't use Access for anything multi-user. Do what Jeff Fritz suggests and use a database that is designed for multi-user access. You may think that your little app is only going to be shared between a few people, but I guarantee you that it'll have a hundred users and fifty new features by the end of the year. And if those are all Access, rather than VB/SQL Express, your Ops people will break into your house one night and slit your throat.
Access isn't a client-server app, and provides very little in the way of backup/restore, or any automation whatsoever. Not to mention the interface and the DB are very tightly coupled... so if you ever want to turn this into a web app, or make any serious changes, your world will be filled with pain.
It's been done so many times by so many generic software engineers where we've seen a .mdb go corrupt in a multi user situation. If so many experienced specialist Access developers can get it right, as I'm inclined to believe, then we generalists must be doing something wrong and that something must be fairly fundamental yet non-obvious for so many of us to run away from the thing screaming 'Never again!' So if you consider yourself to be a experienced specialist Access developer (or you know how to find one) then go for it. But if you are a generalist or casual user looking for a lightweight back end then I suggest you look elsewhere (SQL Server is good IMO).
If your users can wait twice as long for an application with half of the features they want, then don't use Access.
Jet does not have the sophisticated lock logic required to support multi-user scenarios. You can get away with using it if your application is mostly reads and low-contention.
I've seen websites support many users, but I would recommend SQL Express unless you have a compelling reason to choose Jet.
I can tell you from painful experience that Jet 3/3.5 was not reliable. I saw it crash frequently under light load and when there were crashes you risked data corruption. It used to be extremely sensitive to any power problems, any client crashing against it (even the UI linked to the mdb), and any LAN problems. More recent versions of Jet might be better but switching to Sql Server is clearly the way to go in my opinion for anything other than trivial data entry with a small number of users. Sql Express is free and you don't really lose anything, especially if you're UI is in .Net, rather than Access.
EDIT: Microsoft doesn't think you should rely on Jet 4 either.
from: http://support.microsoft.com/kb/303528
Microsoft Jet is not intended for use with high-stress server applications, high-concurrency server applications, or 24 hours a day, seven days a week server applications. This includes server applications, such as Web applications, commerce applications, transactional applications, and messaging server applications. For these types of applications, the best solution is to switch to a true client/server-based database system, such as Microsoft Data Engine (MSDE) or Microsoft SQL Server. When you use Microsoft Jet in high-stress applications such as Microsoft Internet Information Server (IIS), you may experience any one of the following problems:
Database corruption
Stability issues, such as IIS crashing or locking up
Sudden failure or persistent failure of the driver to connect to a valid database that requires re-starting the IIS service
just check whether the db lock file (like .ldb) is there or not. If it is there, somebody is accessing that file. If it is not there, at present there is no one accessing that file and you may proceed. Otherwise, wait for when that file (.ldb) is no longer existing.
If you use a Terminal Server, the performance is real good. We have more solutions up to 50 Users at one Access mdb. Development is real fast and deployment easy.
Problems:
everybody can copy data mdb
no access rights
limited store procedures
optimize (compress and repair) only possible with no use data Database
limit to 2 GB!