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Can Compact on Close Affect User Security?Given how corrupted databases can sometimes have some rather strange
consequences, I was wondering if there is any documented cases where a database corrupted by a failed compact on close operation has caused user security to get screwed up? I've been searching Google and have come up empty so far but, then again, I could be using the wrong search terms. Do any of you security experts have any comments on this possibility? Thanks. Brian Any corruption to an mdb file, from any source, including but not
limited to compact-on-close problems, could cause unpredictable effects to that database, including but not limited to, changing the security settings. So the short answer to your question is Yes - documented or not! HTH, TC "TC" <aatcbbtcc***@yahoo.com> wrote in message Thanks for the answer. I thought that was the case but I take it that it isnews:1133507572.489748.114640@f14g2000cwb.googlegroups.com... > Any corruption to an mdb file, from any source, including but not > limited to compact-on-close problems, could cause unpredictable effects > to that database, including but not limited to, changing the security > settings. So the short answer to your question is Yes - documented or > not! > > HTH, > TC safe to assume that Compact on Close is not known to be the cause of any major problems; i.e., its use shouldn't be avoided. Brian There is nothing wrong with compact on close as far as I know.
But remember that in a split datbase, it will only compact the /code/ - not the /data/. So in my applications, I have code to close all open (bound) forms, so it can then compact the back-end database - the one that actually has all the data. If you're not sure what I mean by split database or front/back ends, google the Access groups for those terms (and FE, BE) for more information on what they mean & why a split design is a good thing. HTH, TC
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"TC" <aatcbbtcc***@yahoo.com> wrote in message I think I must be missing something here. I am using a split database modelnews:1133508623.512798.71530@g43g2000cwa.googlegroups.com... > There is nothing wrong with compact on close as far as I know. > > But remember that in a split datbase, it will only compact the /code/ - > not the /data/. So in my applications, I have code to close all open > (bound) forms, so it can then compact the back-end database - the one > that actually has all the data. > > If you're not sure what I mean by split database or front/back ends, > google the Access groups for those terms (and FE, BE) for more > information on what they mean & why a split design is a good thing. > > HTH, > TC and do understand how that works. For both the FE and the BE I have Compact on Close checked. My understanding is that once the last user exits the application that the BE will close down and that Compact on Close will run. Why would the data in the BE also not be compacted? If it isn't, then that doesn't seem to make much sense. Brian Urk, sorry. For some reason I assumed that you meant that you had
"compact on close" set for the FE files(s), but not necessarily for the BE file. I'm not sure why I made that assumption. Presumeably, if it is set for the BE file in an FE/BE situation, that would compact the BE ok. Cheers, TC "Brian Smith" <dcg_br***@hotmail.com> wrote in message Sorry, but I believe your understanding is incorrect. Having "Compact on news:eSbnuCJ%23FHA.572@TK2MSFTNGP15.phx.gbl... > > I think I must be missing something here. I am using a split database > model > and do understand how that works. For both the FE and the BE I have > Compact > on Close checked. My understanding is that once the last user exits the > application that the BE will close down and that Compact on Close will > run. > Why would the data in the BE also not be compacted? If it isn't, then that > doesn't seem to make much sense. Close" checked in the back-end database will only cause the back-end database to be compacted if you were to actually open the back-end database in Access, as opposed to connecting to it via the front-end. (In other words, it's a pretty useless thing to do! <g>) To automatically compact the back-end, you could add code to your front-end that checks whether or not anyone's currently using the back-end (check whether the corresponding LDB file exists), and, if not, uses the DAO CompactDatabase method to compact the back-end. What I typically do is rename the existing back-end file to something meaningful (such insert a date into it), then use CompactDatabase to compact the renamed file back to the properly named file. That way, I have a backup if necessary. -- Doug Steele, Microsoft Access MVP http://I.Am/DougSteele (no e-mails, please!) Douglas J. Steele wrote:
> Sorry, but I believe your understanding is incorrect. Having "Compact on Ow, I stand corrected. I wasn't 100% positive, which is why I said> Close" checked in the back-end database will only cause the back-end > database to be compacted if you were to actually open the back-end database > in Access, as opposed to connecting to it via the front-end. (In other > words, it's a pretty useless thing to do! <g>) "presumeably". But that was a cop-out, I was foolish not to test it myself. Thanks for the correction. > To automatically compact the back-end, you could add code to your front-end I have this on a menubar option (so the user has to choose it> that checks whether or not anyone's currently using the back-end (check > whether the corresponding LDB file exists), and, if not, uses the DAO > CompactDatabase method to compact the back-end. manually). The option just tries the compact & checks the result. If it works, it worked. If it doesn't, he can try again later. Cheers, TC "TC" <aatcbbtcc***@yahoo.com> wrote in message Since users usually forget, I try and put it as a cleanup activity when I news:1133701517.777918.293000@g47g2000cwa.googlegroups.com... >> To automatically compact the back-end, you could add code to your >> front-end >> that checks whether or not anyone's currently using the back-end (check >> whether the corresponding LDB file exists), and, if not, uses the DAO >> CompactDatabase method to compact the back-end. > > I have this on a menubar option (so the user has to choose it > manually). The option just tries the compact & checks the result. If it > works, it worked. If it doesn't, he can try again later. shut down the switchboard (or hidden form if I've got one) -- Doug Steele, Microsoft Access MVP http://I.Am/DougSteele (no e-mails, please!) I guess another approach, to spread it out a bit, would be to do it
(automatically) on every n'th close. Cheers, TC "TC" <aatcbbtcc***@yahoo.com> wrote in message Funny you should mention that! One app I built, I put a counter in that news:1133710716.010074.262760@o13g2000cwo.googlegroups.com... >I guess another approach, to spread it out a bit, would be to do it > (automatically) on every n'th close. reminded the user to backup to diskette every nth time they used the application (n was configurable). I'd compact first. That was years ago: I don't remember whether I put in logic to handle the backend database exceeding the size of a diskette (although I'm sure I must have). However, given it was a membership application for a fairly small club, I doubt that would have been an issue even yet (if, in fact, they're still using the database) -- Doug Steele, Microsoft Access MVP http://I.Am/DougSteele (no e-mails, please!) Well, now that I think of it, my own application is inconsistent. It
monitors the length of time since the last backup, and gives the user an increasingly strident warning about the impact of not backing-up. (So the backup is still a manual action, but the system warns the user when do do it.) But it doesn't do the same with compact. It /does/ remember how long it was since the last compact, but it does not give the user a warning that it is time for another. I will file a bug report! :-) TC
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"TC" <aatcbbtcc***@yahoo.com> wrote in message I'm starting to get confused with how all of this works and, unfortunately,news:1133701517.777918.293000@g47g2000cwa.googlegroups.com... > > Douglas J. Steele wrote: > > > Sorry, but I believe your understanding is incorrect. Having "Compact on > > Close" checked in the back-end database will only cause the back-end > > database to be compacted if you were to actually open the back-end database > > in Access, as opposed to connecting to it via the front-end. (In other > > words, it's a pretty useless thing to do! <g>) > > Ow, I stand corrected. I wasn't 100% positive, which is why I said > "presumeably". But that was a cop-out, I was foolish not to test it > myself. Thanks for the correction. > > > > To automatically compact the back-end, you could add code to your front-end > > that checks whether or not anyone's currently using the back-end (check > > whether the corresponding LDB file exists), and, if not, uses the DAO > > CompactDatabase method to compact the back-end. Microsoft's documentation isn't helping too much. Is there a property or function which returns the path of the backend database? I thought I could use the Connect property but after using it a few times I keep getting an error message that indicates that I cannot open anymore databases. This is the code I'm using to determine the path of the BE. Public Function DbBELocation() DbBELocation() = Mid(Application.CurrentDb("LinkTable").Connect, 11) End Function Also, I'm assuming that there should be an LDB file that corresponds to the BE database file. Yet, all I'm seeing are LDB files for the FE and for the Workgroup file. Is there any reason why I wouldn't be seeing this file? Thanks. Brian Brian Smith wrote:
> Given how corrupted databases can sometimes have some rather strange Brian, you don't state what errors/problems you are experiencing or what version of Access > consequences, I was wondering if there is any documented cases where a > database corrupted by a failed compact on close operation has caused user > security to get screwed up? I've been searching Google and have come up > empty so far but, then again, I could be using the wrong search terms. Do > any of you security experts have any comments on this possibility? you are using. If you are using Access 2000 and experiencing permission related issues then the problem may be related to how A2K compacts. Its the only version that copies the .mdb file outside the current app folder before compacting (it copies the file to the defined TEMP folder). Because of this the compacted version picks up the permissions of the TEMP folder (under certain conditions) and when copied back to the app folder (after the compact) the permissions may be different from what you expect. There is an MSKB article about this (can't find it off hand). Wait... Goggle has it: http://support.microsoft.com/default.aspx?scid=kb;en-us;295234 -- '--------------- 'John Mishefske '--------------- 
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