Multiple users, avoiding data loss

Hi, Here is the problem
User a reads data from row r in table t
User b reads data from row r in table t
User b updates data and writes back to table t
User a updates data and writes back to table t
User b's update was lost.
We are using custom DAO, JDBC, a transaction level of Read_Committed, a connection pool, Oracle DB and OC4J
I think that the DB would be fine as far as consistency is concerned, but What I'd like to know is the best way to stop user b's update being lost as they would think they had made an update but the DB wouldn't reflect this?
Any help/ideas greatly appreciated

Cheers for responding Avi,
Okay so I need to code it rather than rely on the Database, what is the best way to go?
In my opinion, the real problem is showing user "a"
the row with user "b"'s update. Would a
scroll-sensitive "ResultSet" ensure that? (I don't
know, since I haven't tried it.)This won't be a problem as users a&b are at the same level and can change the same rows.
But once user "a" has overwritten user "b"'s change,
then user "b"'s change is gone. What would you
expect? A message to user "a" saying, 'sorry, you
can't change this row because another user already
has!'Something like that I was thinking of just putting up the jsp again causing the DAO to re-read the record, with a message telling the user what has happened. For this app we can't have customer info (possibly entered by user b) disappear...
Any further ideas? or places to go look?

Similar Messages

  • Multiple Users syncing data on Numbers spreadsheet

    What's the best way for multiple users to share a numbers spreadsheet and upkeep of data?
    Thanks! I know- I'm pretty new at this.

    All I know is in the following thread, I have no personal experience with it:
    http://discussions.apple.com/thread.jspa?messageID=10209828&#10209828
    I hope that helps.

  • Time Capsule with multiple users. Data Safe?

    Hi.
    I was just wondering if the I use Time Capsule with multiple users (multiple macs) I believe the backups are all seperated and password protected. Am I right?
    But what about the migration assistant? Doesn't the migration assistant help you to transfer your data from one mac to your new one without asking for a password? So wouldn't it be easy to use the migration assistant to get data of another time capsul backup?
    At the work place of my girlfriend they are using time capsul, and I'm not sure if I would advise her to backup her data to that timecapsule. Ok you can exclude folders, but not the mailaccount.

    Youknowthebo wrote:
    Thanks for the reply.
    But isn't it possible to transfer data from an old user account to a new account with a different name? Wouldn't that overide the password prompt?
    No more or less than on your Mac.
    I mean I understand that if you migrate a user account from one mac to another you wouldn't gain access to the home folder of that user, but as I understood the migration assistant it is possible to migrate data to a folder of your choice. I did not try it yet but that's what I (maybe misunderstood) read here http://web.me.com/pondini/Time_Machine/19.html
    No. You can select which user accounts to transfer, but you can't transfer one user's data to another.

  • How do I avoid data loss during setup?

    Hi All,
    Update: below is my original question/concern. But since posting, I've come across others posting about data loss at various stages of install and initial setup and syncing. None of those posts have been replied to, and I think many of us need some answers. So after reading one guys calendar got scrubbed, I checked mine and the same thing... I had synced through iTunes before upgrading, and all my freshly updated calendar events had been erased when I enabled iCloud. Honestly, what is it with Apple's obsession with deleting people's data when adding new equipment or services?
    So add to my question below, a how to for getting data from existing devices to cloud w/o having cloud erase files and data from devices...
    I'm just setting up. I want to go into this cloud thing slowly, starting with just calendar syncing.
    I go to settings: Documents and Data and click it off. I get a pop up witch says "All documens and Data stored in iCloud will be deleted from this iPad"
    What?
    This switch was in the on position upon install. Have my Documents and data already been scarfed to the cloud, where now if I turn off the feature I lose my files?
    And what about down the road if one wants to turn off the feature after it's been in use? Doe my iPad get scrubbed of my files?
    Am I learning that once my files get sent to the cloud, the server holds a copy which I can never scrub off iCloud?
    The way that warning reads, my only option for taking a device off the grid is to have my data scrubbed from that device.
    What am I missing? I want to control which of my data makes it to the cloud. This says they take it all up front and steal my copy if I try to get my device off the grid. No?
    Please help me understand how to control which of my files go to the cloud, and how not to have my files removed from my device if I chose to opt out of the docs and data sync feature?
    S.
    PS why would they ever make that a consequence of turning off the feature?

    Unless you have signed up for AT&T's international roaming for phone calls, I suggest putting the device into Airplane mode. That is what I did when I did the 3 day Bahamas Cruise. And to support what AmishCake said, the cruise lines charge for their wi-fi. Generally a daily 24-hour charge, or they will have a special for the length of the cruise, but it is pricey.

  • Multiple users uploading data to Live cache

    Sorry posted in wrong thread. Please find this thread in Master data and general.
    Closing this one
    Hello ,
    Does APO has the capability to handle flat file uploads simultaneously to live cache  by 5 different users or does it throw out a message asking other users to wait until one upload is finished.
    We have a situation where users upload the flat files and based on these files the CVC creation process kicks off (If there are any new combinations). But every time more than one user tries to upload the file the system would nt allow other users to upload.
    Any help or input is highly appreciated.
    Thank you,
    Sai
    Edited by: st.sapscm on Jan 11, 2012 12:01 PM

    Thanks a lot of the prompt reply.
    Let me be more specific. The users upload sales data to APO (APO Info cube) in Work week versions. So the planners usually don't upload same CVCs but sometime they do upload all at once, say once every week or month.
    So when you say "Object" say the object in my case is APO BW infocube. The second part of your response compliments the idea that it might not be possible to do a simultaneous upload. Correct me if i am wrong. I am a little confused with the very first statement  ("Yes it is possible..." and the second part of you response about the locking.
    Can you please explain what would happen in each case when the recipient is 1. Info cube 2. Planning area
    Thanks a lot.
    Sai

  • How to avoid data loss when an action is perfomed ....

    hi,
    I am using a dynamic Tab. Each tab contains a seperate jsp page.( the jsp page is included for the corresponding tab). Each page can contain more than 25 fields. The problem is for example i will select some check box in the first tab and i will go the second tab and i will do some insert operations , when i came back to the first tab , the checkbox which i had selected or the text what i had entered should be there. If it can be solved by using AJAX, pls guide me.
    Tools i am using : jsp, struts.
    Looking forward to hear to solve this problem.

    hi....
    c through that when u eturn to tab.... set the form values to the page
    i mean if u r using a form bean for ur jsp. use name name atrribute of the sturts html tag. and give the form bean name to the name attribute i hope this would solve your problem
    thaks
    with rgards
    shekhar

  • Downgrade Admin to "Managed with parental controls" - no data loss?

    I want to change my daughter's iMac account (originally my wife's computer) from "Admin" to "Managed with parental controls."
    Is this possible while saving all of her school work/music/etc. which are now under the admin login/account? Or do I backup her home folder, delete the admin account, add a new one for me, then put her back in as "Standard" and go from there?
    Hope there is an elegant/easy way to avoid data loss while still upgrading security on her usage...
    Thanks in advance!
    Kevin

    hi k,
    yes you can down grade her account and enable parental controls. This will not delete her content such as itunes, photos, documents, extra.
    if you haven't done so already, make another administrator account with you will use to manage the computer. Make sure the account has a password; and that password is not the same as her password.
    then Login with the new administrator account.
    go to system preferences and click on accounts. unlock accounts by clicking on the lock. click on the old administrator account. now uncheck allow this user to administrate this computer. then check enable parental controls. then click on the open parental controls button.
    you can now configure parental controls.

  • External Drives for Mac Experiencing Data Loss with Maverick OS -- UPDATED FOR NOVEMBER 6, 2013

    --- Updated November 6, 2013 ---
    On October 30th, 2013 Western Digital informed registered customers of affected products via E-mail regarding reports of Western Digital and other external HDD products experiencing data loss when updating to OS X Mavericks (10.9).  Our investigation to date has found that for a small percentage of customers that have the WD Drive Manager, WD Raid Manager and/or WD SmartWare software applications installed on their Mac, there can be cases of a repartition and reformat of their Direct Attached Storage (DAS) devices without customer acknowledgement which can result in data loss.  
    WD has been tracking this issue closely through our WD Forum and through our Technical Support hotline and the occurrence rate of this event has been very low.  A specific set of conditions and timing sequences between the OS and the WD software utilities has to occur to cause this issue.  Should this event occur, the data on the product can likely be recovered with a third party software utility if the customer stops using the device immediately after the OS X Mavericks (10.9) upgrade.  WD will be issuing updated versions of these software applications that resolve this issue.
    WD strongly urges our customers to uninstall these software applications before updating to OS X Mavericks (10.9), or delay upgrading until we provide an update to the applications.  If you have already upgraded to Mavericks,  WD recommends that you remove these applications and restart your computer.  If you have already upgraded to Mavericks and are experiencing difficulty in accessing your external hard drive,  please do not save anything to the drive, disconnect the drive from your computer, and contact Western Digital Customer Service at http://support.wdc.com/contact/.
    --- Updated November 5, 2013 ---
    There are reports of Western Digital and other external HDD products experiencing data loss when updating to Apple's OS X Mavericks (10.9).  Western Digital is urgently investigating these reports and the possible connection to the WD Drive Manager, WD Raid Manager and WD SmartWare software applications. 
    Until the issue is understood and the cause identified, WD strongly urges our customers to uninstall these software applications on their systems before updating to OS X Mavericks (10.9), or delay upgrading.  If you have already upgraded to Mavericks, WD recommends that you remove these applications and restart your computer. WD has removed these software applications from our web site solely as a precaution as we investigate this issue.
    If you have already upgraded to Mavericks and are experiencing difficulty in accessing your external hard drive, please do not save anything to the drive, disconnect the drive from your computer, and contact Western Digital Customer Service at http://support.wdc.com/country/ for further assistance.
    You can now download the WD Software Uninstaller.  This utility will remove Mac WD SmartWare and WD Drive Manager software.  You can find the uninstaller under any of the Mac Drive Downloads sections such as the My Book Studio below.
    http://support.wdc.com/product/download.asp?groupid=124&sid=214&lang=en

    I agree. After installing Mavericks I was troubleshooting and reinstalling drivers for days. Many Apps did not work anymore, although the updates slowly arrive. As total divergence of the old Apple philosophy, I had to use endless library cleaning terminal commands to get a new Canon network printer running again. Canon provided the procedures after updating from OS X10.6 to 10.7 already. Now it seems, that the first time I used the Super Drive (CD-DVD Drive) trying to burn an audio CD with baffling error messages (Drive already used..). After this, the RAID1 status of the two MyBook archives changed to JBOD. The changes of OS X10.8 to 10.9 I find unnecessary (iBooks could be an App, Maps we have already the same on other channels). Some changes are even a step back (calendar graphics), the so much more user friendly Office suite iWorks is free, but degraded an of limited use!MadOverlord wrote:
    I have had multiple cases of data loss on WD drives since upgrading to Mavericks, and I do not use any WD software. I was using a 4-bay PROBOX USB3 enclosure with 4 independant drives, each with 1 volume, no RAID. I have managed to copy large files off the WD drive onto my MBP internal drive using the finder, and then find that they are not identical. This problem is intermittent, does not generate any Finder errors, and the drives all show 100% health via SMART. The configuration was rock-solid before Mavericks, and has trashed the directories of 4 drives since I upgraded last week. I am attempting to find a solid replication case for this, but it is difficult. I have not been able to replicate the issue on another 2-bay USB2 dock that I have (different manufacturer). One thing is clear: only one thing changed -- I upgraded to Mavericks. 

  • Pages '09 data loss - can I recover it?

    Last night I saved a 131 page document to my RAID airdisk (purposefully a RAID array to avoid data loss). I then copied the document over to my iDisk for additional safe keeping. When I sat down again to edit it about 22 hours later, ALL COPIES of the document had been reduced to just 12 pages. I saved the document at 11pm the night before and the copies all list that time as the last time the document was accessed.
    Is there anything I can do to get the data back? Anything I can do to avoid this problem in the future? It is an ongoing project so I save out drafts once a week to chart my progress. All of those documents are 100-120 pages and are still intact on both the iDisk and the airdisk.
    Any ideas would be greatly appreciated.

    Hi!
    This has been up in the forum many times. Do a search here in Discussions and you'll get answers.

  • Multiple users accessing the same data in a global temp table

    I have a global temp table (GTT) defined with 'on commit preserve rows'. This table is accessed via a web page using ASP.NET. The application was designed so that every one that accessed the web page could only see their data in the GTT.
    We have just realized that the GTT doesn't appear to be empty as new web users use the application. I believe it has something to do with how ASP is connecting to the database. I only see one entry in the V$SESSION view even when multiple users are using the web page. I believe this single V$SESSION entry is causing only one GTT to be available at a time. Each user is inserting into / selecting out of the same GTT and their results are wrong.
    I'm the back end Oracle developer at this place and I'm having difficulty translating this issue to the front end ASP team. When this web page is accessed, I need it to start a new session, not reuse an existing session. I want to keep the same connection, but just start a new session... Now I'm losing it.. Like I said, I'm the back end guy and all this web/connection/pooling front end stuff is magic to me.
    The GTT isn't going to work unless we get new sessions. How do we do this?
    Thanks!

    DGS wrote:
    I have a global temp table (GTT) defined with 'on commit preserve rows'. This table is accessed via a web page using ASP.NET. The application was designed so that every one that accessed the web page could only see their data in the GTT.
    We have just realized that the GTT doesn't appear to be empty as new web users use the application. I believe it has something to do with how ASP is connecting to the database. I only see one entry in the V$SESSION view even when multiple users are using the web page. I believe this single V$SESSION entry is causing only one GTT to be available at a time. Each user is inserting into / selecting out of the same GTT and their results are wrong.
    I'm the back end Oracle developer at this place and I'm having difficulty translating this issue to the front end ASP team. When this web page is accessed, I need it to start a new session, not reuse an existing session. I want to keep the same connection, but just start a new session... Now I'm losing it.. Like I said, I'm the back end guy and all this web/connection/pooling front end stuff is magic to me.
    The GTT isn't going to work unless we get new sessions. How do we do this?
    Thanks!You may want to try changing your GTT to 'ON COMMIT DELETE ROWS' and have the .Net app use a transaction object.
    We had a similar problem and I found help in the following thread:
    Re: Global temp table problem w/ODP?
    All the best.

  • Working with multiple users and computers, but shared data

    Sorry if this is posted in a poor place, I'm not sure where the best place is. This is sort of a general questions.
    For a long time, my wife and I have had either one computer, or two machines but one has definitely been just a terminal. We've basically set up all of our data to be one one primary machine, and if we want to view/edit that data we have to use that machine.
    We just got a new MacBook Pro and I would like to be able to use two machines as equals. Sadly, this idea of multiple computers, with two users and some shared data is really giving me difficulty. I was wondering if anyone has any suggestions on how to best manage things like:
    Synchronizing portions of our contact list (We share about 50% of the combined library -- we don't have to share all though).
    How to manage iPhoto so that we can each have access to the photos. As an added difficulty (or maybe this is easier?) my Wife just wants to have access to the pictures for viewing and sharing on Facebook/Picassa/etc. I am the only one who wants to edit, correct and cull our library. That said, I always edit when I first put the data on the machine, and almost never again; so it would be fine to have one (or both accounts) set up as view only for the iPhoto data.
    How to manage iTunes so that we can each have access to the music. As a super awesome bonus, it would be great if we could have three libraries: His, Hers and Shared. Maybe as much as 30% of our music library is similar, the rest just gets in the way.
    What is the best solution people have found for calendars? (I'm thinking two separate calendars, and we each subscribe to each others iCal feed)
    Mail.app and bookmark synching is not really a problem for us.
    Two extra points:
    * One machine is portable, and the other isn't. Ideally, when the laptop is out of the house, both machines should still have reasonable access to the shared data. That is: Just dumping things in the shared folder won't work because when the laptop is out of the house we will be disconnected from the source data.
    * We just got a second iPhone. This means that both of us will be taking photos/video separately and trying to synch back to the master data store.
    * Basically, I'm trying to minimize data duplication as much as possible, and just synchronize the systems to each other.
    Thanks a ton in advance. If anyone has any suggestions at all, I would love to hear them. Including "This is in the wrong forum, go ask here instead..."

    So you have a desktop Mac and a laptop Mac, right? Two user accounts (and a third admin account) on each computer, right?
    I profess that I haven't tried this, but here is how I would approach your problem:
    Sharing Music and Photos between multiple user accounts on the same computer: 
    See if http://forums.macrumors.com/showthread.php?t=194992 and http://forums.macrumors.com/showthread.php?t=510993 provide any useful information to assist you in this endeavor.
    Sharing across multiple computers:
    Turn on file sharing on the Desktop (System Preferences > Sharing). Now you can mount the Desktop as an external drive on the laptop's Desktop. Copy the music and photo folders across. Will take awhile to do the first time. Then, for future use, get a copy of the donationware CarbonCopyCloner or equivalent. You can use CCC to selectively sync specific folders from one computer to the other. There may be a hassle with digital copyright issues on music and movies, though.
    Calendars:
    As you have suggested yourself, publishing yours and subscribing to hers is probably the best way to do it, on the same computer. Across computers, syncing with CCC or equivalent would probably be the way to go.

  • Multiple users on a itunes account how do I avoid eveyone getting my information on icloud

    I have multiple users on our itunes account. If I switch to mountain lion and utilize icloud how do I avoid the other phones my kids and husband from getting all my stuff on their phones. I am the primary account holder when we first upgraded the phones all my contacts went to their phones and wiped out all of theirs it was a night mare so we just shut it off. It sounds like a cool idea but I dont want to mess up their contacts and information.

    You can keep everyone on your iTunes account all you have to do is have everyone create there own iCloud account. Me, my wife, and my son all have our own iCloud for our own use. I have my 3 devices linked to mine, my son has 2 linked to his and my wife has 2 also. For some reason by default the iDevice will ask you to use your iTunes account but you don't have to. You can create it right from the device itself if you want a @me account which is the way to go IMO. you can also go to iCloud.com and create it there too. We have a total of 8 devices linked to one iTunes account for purchases and everything works like a champ. Hope this helps.

  • Data in the table changes when multiple users try to submit data

    I have a dynamic table. The table is created in the wdDoModifyView. The user can load data into the table from an excel file. So I have a "Load" button that loads the data from the selected excel file to the table. I also have a "Submit" button. This "Submit" button converts the data to an xml file and make a call to an oracle stored procedure for validation check. If there's an error it will be returned and displayed to the user. If none, a summary of data for posting will be displayed to the user. If the data is correct and the user hit the ok button, the same data will be return to oracle sp for loading in the table.
    The problem we encountered is when multiple users are loading and submitting at the same time, the data displayed in the dynamic tables changes after clicking the ok button. It is as if, the table displays the data being loaded by other user.
    This is an error that is difficult to recreate. This doesn't happen all the time. I hope you somebody could enlighten me why this is happening. I'm not sure if it has something to do with multithreading or session.
    Edited by: Marlyn Agco on Apr 14, 2009 3:57 PM

    Hi Armin,
    Did you mean storing view instances in static references and accessing them outside the wdDoModifyView is not a good idea? In wdDoInit the nodes are dynamically created according to the xml file being returned by the database. This node is stored in a static variable which is also used in wdDoModifyView to create the dynamic table.
    What do you suggest? We're still encountering same issue when multiple users are uploading data.

  • How to prevent multiple users from updating the same data in coherence

    Hi,
    I have a Java Web Application and for data cache am using coherence 3.5. The same data maybe shared by multiple users which maybe in hundreds. Now how do I prevent multiple users from updating the same data in coherence i.e. is there something in coherence that will only allow one user a time to update. If one user is in a process of updating a data in coherence and some other user also tries to update then the second user should get an error.
    Thanks

    I have a question on the same line. How can I restrict someone from updating a cache value when I a process is already working on it. I tried locking the cache key but it does not stop other process to update it , it only does not allow other process to get lock on it.

  • Prevent multiple users from updating coherence cache data at the same time

    Hi,
    I have a web application which have a huge amount of data instead of storing the data in Http Session are storing it in coherence. Now multiple groups of users can use or update the same data in coherence. There are 100's of groups with several thousand users in each group. How do I prevent multiple users from updating the cache data. Here is the scenario. User logs-in checks in coherence if the data there and gets it from coherence and displays it on the ui if not get it from backend i.e. mainframe systems and store it in coherence before displaying it on the screen. Now some other user at the same time can also perform the same function and if don't find the data in coherence can get it from backend and start saving it in coherence while the other user is also in the process of saving or updating. How do I prevent this in coherence. As have to use the same key when storing in coherence because the same data is shared across users and don't want to keep multiple copies of the same data. Is there something coherence provides out-of-the-box or what is best approach to handle this scenario.
    Thanks

    Hi,
    actually I believe, that if we are speaking about multiple users each with its own HttpSession, in case of two users accessing the same session attribute in their own session, the actually used cache keys will not be the same.
    On the other hand, this is probably not what you would really like, you would possibly like to share that data among sessions.
    You should probably consider using either read-through caching with the CacheLoader implementor doing the expensive data retrieval (if the data to be cached can be obtained outside of an HTTP container), or side caching with using Coherence locks or entry-processors for concurrency control on the data retrieval operations for the same key (take care of retries in this case).
    Best regards,
    Robert

Maybe you are looking for