I have an ACCDB that I split a while ago that contains many forms with sub forms (based on tables) and over two hundred tables in the BE (almost all are small lookup tables for vehicle objects) and 400+ queries. There also happens to exist another ACCDB with a single table in it with 6.5M rows that the FE links to with basic history info. The two backends do not link to each other in any way. The FE is 14MB, BE is 1.2G and the single table DB is 900MB, all with primary keyes and indexes setup appropriately. The DB is 100% normalized. Both BE's grow 5% every month. The DB is currently slated to be migrated to an Oracle 11G environment later this year.
Question:
I found out recently that if I compact and repair the back end or front end that none of the forms containing subforms open; the whole FE just freezes to white. Even if all 3 are repaired I still have issues. BUT if I compact/repair all 3 as well as relink the entire front end to the two backends the forms all of sudden start working. It was only recently that this behavior began.
Why do I have to relink to make the forms work again?
You should not have to re-link anything here at all after a C+R.
The only thing that comes to mind is the user who is doing the C+R has some restricted rights in the folder or directory where the C+R occurs.
Remember, when the user does the C+R, then a COPY of the file is created – and thus possible inheriting of the CURRENT user’s rights can occur WHEN the NEW file is created. So it sounds like some permissions issues exists on the folder, or the user that is doing the C+R has some special (different) rights. (perhaps some inherited rights do to membership in some security group).
Of course one should ensure that you are using UNC path names, and of course the front end needs to be placed on each machine.
Perhaps again the user doing the C+R has “different” drive mappings and thus links to the back end databases are thus wrong due to different drive letter. So if not already, as a general rule I would STRONGLY avoid drive letters and use NC path names (if you not already).
If you are using UNC path names, then the likely issue is permissions.
There also a possibility that the new user doing the C+R is running the front end from a “non” trusted location.
Also, the table of 6.5 million rows seems a bit large, and I assume the 1.2 gig size is RIGHT AFTER a C+R? (but this issue is for another post).
This suggests a drive mapping issue, a permissions issue, or perhaps the user launching the application is messing up references. I would shift by-pass into the application and ensure that the user doing the C+R can compile the application, and would from VBA editor take CAREFUL note that say office 14 references are not being hi-jacked to office 15 references for example.
You're reaching the "hassle-free" viable (as opposed to "documented") limits of Access as a database. remember the queries need to be compiled which means resolving all the table links, and verifying existing indexes and other meta-data. it's possible that simply over-writing this information by manually using the linked table manager as you have, may be more efficient.
Here's a few prescribed tips which might help you out:
http://office.microsoft.com/en-gb/access-help/improve-performance-of-an-access-database-HP005187453.aspx
And some more...
http://www.fmsinc.com/MicrosoftAccess/Performance.html#Linked%20Tables
And a related thread from this site:
Proper way to program a Microsoft Access Backend Database in a Multiuser Environment
Issues which may not be helping you:
queries which don't restrict the dataset sufficiently, particularly those running a dynaset
backed database files sitting too low in the windows folder structure (the higher the better)
As the 2nd link suggests, the truth is there are so many variables at work that resolving this will require some tinkering, with trial & error playing a major part.
All that, or you can upsize to SQL Server Express :)
http://office.microsoft.com/en-gb/access-help/move-access-data-to-a-sql-server-database-by-using-the-upsizing-wizard-HA010275537.aspx
Related
I'm planning on using rxdb + hasura/postgresql in the backend. I'm reading this rxdb page for example, which off the bat requires sync-able entities to have a deleted flag.
Q1 (main question)
Is there ANY point at which I can finally hard-delete these entities? What conditions would have to be met - eg could I simply use "older than X months" and then force my app to only ever displays data for less than X months?
Is such a hard-delete, if possible, best carried out directly in the central db, since it will be the source of truth? Would there be any repercussions client-side that I'm not foreseeing/understanding?
I foresee the number of deleted's growing rapidly in my app and i don't want to have to store all this extra data forever.
Q2 (bonus / just curious)
What is the (algorithmic) basis for needing a 'deleted' flag? Is it that it's just faster to check a flag rather than to check for the omission of an object from, say, a very large list. I apologize if it's kind of a stupid question :(
Ultimately it comes down to a decision that's informed by your particular business/product with regards to how long you want to keep deleted entities in your system. For some applications it's important to always keep a history of deleted things or even individual revisions to records stored as a kind of ledger or history. You'll have to make a judgement call as to how long you want to keep your deleted entities.
I'd recommend that you also add a deleted_at column if you haven't already and then you could easily leverage something like Hasura's new Scheduled Triggers functionality to run a recurring job that fully deletes records older than whatever your threshold is.
You could also leverage Hasura's permissions system to ensure that rows that have been deleted aren't returned to the client. There is documentation and examples for ways to work with soft deletes and Hasura
For your second question it is definitely much faster to check for the deleted flag on records than to have to try and diff the entire dataset looking for things that are now missing.
I am not very sure whether this is the right forum to ask this question or not.
We are having a TallyERP9 server with Multiple Licenses. Now our 3 users working remotely on the same Data. We have set up Google Drive for Data Syncing. But most of the time its giving issue due to synchronisation process.
What could be the best soltion so that multiple users can work on same data from Remote Locations?
This is the answer - http://mirror.tallysolutions.com/Downloads/TallyTips/GettingStartedwithDataSynchronisation.pdf
Thanks to #MitaleeRao...
Edit placed here for brevity:
These are 2 points I've noted regarding the Tally architecture:
The database is a flat file in a tree structure, and there are numerous checkpoints at each level for maintaining this inheritance (for e.g., a voucher has inventory entries that have stock items, which have units, etc.).
The SOAP XML protocol that Tally uses does not have multi-threading capabilities - i.e., the Tally server will only accept one request and give a response at a time.
The Data syncronisation that Tally has introduced is probably the automating of exporting the XML of all masters/vouchers and importing them onto the central Database (whether on the Tally.NET server or on a local computer with a static IP). Not sure how the Google Drive client works, but I'm assuming it is a variation of the same (i.e., XML based data export and then import onto a main computer).
I would like to change the properties of multiple diagrams together rather than clicking on them one by one. Does anyone know how this can be achieved?
You can use the scripting facility of Enterprise Architect to loop the diagrams you would like to change and update them.
See this section of the manual to get help.
There is a bunch of example scripts included with EA, either from the local scripts, or from the EAScriptLib MDG.
Another source of examples is my Github repository: https://github.com/GeertBellekens/Enterprise-Architect-VBScript-Library
You could write a SQL to manipulate your database. t_diagram.PDATA holds a long cryptic string where one part is ScalePI=0; (which is the default for no scaling). You can alter that to be ScalePI=1; (meaning scale to one page).
String manipulations vary from database to database. So you need to write your own which you can execute in a script using
Repository.Execute("UPDATE t_diagram ...")
Note that you should test this in a sandbox first since invalid SQLs can easily disrupt your whole repository.
Okay there are similar questions to this but this is NOT a duplicate. This error seems to come up when you have parameters referencing a dataset which is shared. Deleting the report from the server and redeploying does not fix in my case.
So I am developing on VS 2010 Professional with Business Intelligence Development Studio, BIDS, which is under source control with Team Foundation Server. I am deploying to a 2008R2 server which I thought may be the issue. The workaround is to change the dataset references to be embedded instead which stops this error dead in it's tracks but that is pretty poor in my opinion and I would like to have this work with shared datasets ultimately.
Things I have tried:
Ensure the naming of the dataset matches the reference. EG: "Name is ClientQuery, shared dataset is ClientQuery"
Ensure the naming on the server matches the refernces in step 1.
Ensure that this is what is breaking it by removing the reference to the shared dataset, works right away then.
Ensures that the shared dataset is not enabling some type of caching on the server.
I had a filter on a second shared dataset limiting scope, I removed that and there was still an error.
Removed all parameters and only added a single shared dataset, it gives error right away.
Added an option to the parameters binding to say: "Allow Empty values". Did this with Nulls as well.
Recreated EVERYTHING, a whole brand new RDL file, and copy and pasted only elements on the body of the report but explicitly created the parameters and the datasets and this STILL HAPPENED.
9. UPDATED - I have done the old destroy the RDL and then hope to redeploy. I found that a lot online. That does not work in this case. It is almost like this reference in the RDL:
< DataSet Name="**ClientQuery**">
< SharedDataSet>
< SharedDataSetReference>**ClientQuery**</SharedDataSetReference>
< /SharedDataSet>
< Fields>
< Field Name="CUSTOMER_ID">
< DataField>CUSTOMER_ID</DataField>
< rd:TypeName>System.String</rd:TypeName>
< /Field>
< Field Name="CUSTOMER_NAME">
< DataField>CUSTOMER_NAME</DataField>
< rd:TypeName>System.String</rd:TypeName>
< /Field>
< /Fields>
< /DataSet>
It appears that somehow the mention of this refernce causes havoc. I would examine my bin(environment) directory under my project. (I deploy for multiple environments and set up QA, UAT, PROD, etc.. under solution config) Each time the RDL is getting updated as it should and posting the updates I am showing. I think 'rebuild' is a lot of the issue at times when people see their report files not updating on a server, in my case a rebuild usually gets updates to the RDL versus just hitting deploy first.
While all of this is happening the hard part is that it works throughout changes every time on BIDS seamlessly. So the error is dealing completely with what the source server believes the rdl data to represent.
Any help is much appreciated, I would rate myself advanced at SSRS but this one has me stumped of what the error is refernecing that it is not getting.
I know this is an old question, but I just ran across this and was able to resolve my issue. Thought an updated option is warranted for others struggling with it. My issue had to do with the parameter settings on the Shared Dataset properties. The menu looks like this:
Specifically, make sure that you check the "Allows null value" option where needed. This instantly resolved my issue where a dataset would not work when pointing to a shared but embedding the dataset did.
Okay so the answer Jeroen proposed and others is half right. My issue was that my source code was under an older SVN Source Control, that was deployed to an SSRS 2008 Server, then we migrated the code base to TFS Source Control. The issue appears to be that the Shared Datasets were BELIEVING to be different identifiers than they actually were. The simple work around IN ADDITION to deleting the files is to redeploy the shared datasets as well. In my case I went into my project settings and deployed them to a different location entirely under the report structure to keep them in the same area so: Reports/Datasets instead of just Datasets. This seems to clear up the issue in my case so I believe this was just a perfect storm. In doubt with SSRS just delete everything and start from the ground up I guess.
I keep seeing questions floating through that make reference to a column in a database table named something like DateLastUpdated. I don't get it.
The only companion field I've ever seen is LastUpdateUserId or such. There's never an indicator about why the update took place; or even what the update was.
On top of that, this field is sometimes written from within a trigger, where even less context is available.
It certainly doesn't even come close to being an audit trail; so that can't be the justification. And if there is and audit trail somewhere in a log or whatever, this field would be redundant.
What am I missing? Why is this pattern so popular?
Such a field can be used to detect whether there are conflicting edits made by different processes. When you retrieve a record from the database, you get the previous DateLastUpdated field. After making changes to other fields, you submit the record back to the database layer. The database layer checks that the DateLastUpdated you submit matches the one still in the database. If it matches, then the update is performed (and DateLastUpdated is updated to the current time). However, if it does not match, then some other process has changed the record in the meantime and the current update can be aborted.
It depends on the exact circumstance, but a timestamp like that can be very useful for autogenerated data - you can figure out if something needs to be recalculated if a depedency has changed later on (this is how build systems calculate which files need to be recompiled).
Also, many websites will have data marking "Last changed" on a page, particularly news sites that may edit content. The exact reason isn't necessary (and there likely exist backups in case an audit trail is really necessary), but this data needs to be visible to the end user.
These sorts of things are typically used for business applications where user action is required to initiate the update. Typically, there will be some kind of business app (eg a CRM desktop application) and for most updates there tends to be only one way of making the update.
If you're looking at address data, that was done through the "Maintain Address" screen, etc.
Such database auditing is there to augment business-level auditing, not to replace it. Call centres will sometimes (or always in the case of financial services providers in Australia, as one example) record phone calls. That's part of the audit trail too but doesn't tend to be part of the IT solution as far as the desktop application (and related infrastructure) goes, although that is by no means a hard and fast rule.
Call centre staff will also typically have some sort of "Notes" or "Log" functionality where they can type freeform text as to why the customer called and what action was taken so the next operator can pick up where they left off when the customer rings back.
Triggers will often be used to record exactly what was changed (eg writing the old record to an audit table). The purpose of all this is that with all the information (the notes, recorded call, database audit trail and logs) the previous state of the data can be reconstructed as can the resulting action. This may be to find/resolve bugs in the system or simply as a conflict resolution process with the customer.
It is certainly popular - rails for example has a shorthand for it, as well as a creation timestamp (:timestamps).
At the application level it's very useful, as the same pattern is very common in views - look at the questions here for example (answered 56 secs ago, etc).
It can also be used retrospectively in reporting to generate stats (e.g. what is the growth curve of the number of records in the DB).
there are a couple of scenarios
Let's say you have an address table for your customers
you have your CRM app, the customer calls that his address has changed a month ago, with the LastUpdate column you can see that this row for this customer hasn't been touched in 4 months
usually you use triggers to populate a history table so that you can see all the other history, if you see that the creationdate and updated date are the same there is no point hitting the history table since you won't find anything
you calculate indexes (stock market), you can easily see that it was recalculated just by looking at this column
there are 2 DB servers, by comparing the date column you can find out if all the changes have been replicated or not etc etc ect
This is also very useful if you have to send feeds out to clients that are delta feeds, that is only the records that have been changed or inserted since the data of the last feed are sent.