Database Design/Application architecture question

I'm working on a Java web app that includes creating a database from scratch. The UI needs to model a mostly static set of choices that led to other choices that lead to other choices..... I'm trying to figure out how to model this in a table or set of tables and how to design the UI and servlet interaction. Here's an example, in Petstore lingo:
Do you need a dog house?
For a small dog?
Red?
Blue?
How many?
For a big dog?
Brown?
Yellow?
How many?
Side windows?
Do you need a bird cage?
How many water dispensers?
For big bird?
This sort of multiple dependent options seems hard to model in a database. I'm trying to do this at the database level so that I can have a dynamic front end, in which I get the collection of options and then use JSTL to populate the UI with the chocies for whatever level or step I'm at. Any suggestions? I haven't had to solve a design problem precisely like this where some choices may have dependent choices, but others do not, and some have dependent choices which have very specific dependent choices that have very specific dependent choices. Thanks.
Ken

I'm working on a Java web app that includes creating
a database from scratch. You mean the UI drives creating the database?
Why?
That is often driven by developer rather than business requirements and is often a bad idea. It is often done solely so the developer doesn't have to type as much. And not typing very much is solved by code generation while using meta data solutions for it is usually a bad maintainance idea.
But if you need to then you create meta data.
Table TheValues
- Field: Value Id.
- Field: Value Name
- Field: Value Value
Table: Collection
- Field: Collection Id
- Field: Collection Name
Table: Link table
- Field: Collection Id
- Field: Id type
- Field: Id (Collection or Value)
Display values can be kept in another table or used directly.
Notice that a collection can contain another connection.
You can combine the first two tables as well.

Similar Messages

Data Gathering Application - Architecture Question

I'm working on revising an existing application that's used to collect data gathered by users from various sources (various computer systems, paper files, discussions/interviews with other employees, etc.) which is then used for analysis and reporting of level of compliance with mandates at various levels (overall, location, individual).
The existing application gathers data via two basic form types: one is for a specific individual having multiple data points; the other is for everyone in the location with multiple data points. For example, type 1 looks like:
Person
Question 1 Response 1
Question 2 Response 2
Question N Response N
While the Type 2 form looks like:
Location
Person 1 Question 1 Question 2 ... Question N
Person 2 Question 1 Question 2 ... Question N
Person N Question 1 Question 2 ... Question N
The questions are grouped by types of information being analyzed, so that those questions appear on different pages and may apply to different sets of individuals or locations. Not all locations are required to gather information on the same questions, depending on their compliance level last year. So, location A may have to answer questions 1, 2 and 3, while location B may answer questions 1, 3 and 4.
My question is this: The table used to store the data is structed like:
Person ID, location, page, q1, q2, ..., qN
To continue the above example of locations A and B, both locations would store the responses in columns q1, q2, and q3 since they had three questions that applied to them. We can then reconstruct which question the response applies to by checking which questions applied to the location. We're using the apex api in the query to generate select-list items for the questions with the valid responses for each question (some are yes/no, others allow NA, a number 1-3, or a typed-in positive integer for a couple of questions).
Since we need to maintain the data from two forms (either for an individual or for all individuals at a location), would it be easier to maintain in APEX using a table that stores each question in a separate row?
PersonID, location, Page, question, response
Further, we want to simplify the application which currently uses a separate page for each item type which is customized to the max number of questions for that page for the year. Instead we want to make a more generic set of pages that can at least handle an arbitrary number of items or, ideally, however many questions may be applicable in the future. While we can assume that the practical upper limit would be 30 questions, in the future it is possible we could be mandated to ask several times that number, maybe 100 or more.
The main goal is to make the application robust to handle the questions consistenly, no matter how many are defined for a type and no matter how many are required for the selected individual or location.
I'm already working on the page simplification process by replacing literals with session-state and application items, and realize that to make the pages robust we'll have to convert from static queries to generating the query from plsql using generic columns for the report in APEX.
If anyone could share their thoughts/experience with this type of application, your input is greatly appreciated.
Thanks,
Richard

Hi Richard,
I find it bad practice to make a table PersonId, location, page, q,q1 .. qN
it will do more harm in analysing the data than you will benefit in collecting the information.
In my opinion you should normalize it a bit more. Seperate table for Person, with it's attributes. and if it is a 1 to 1 relation, also an locationId. Then a seperate table to hold the location information. Then you are having questions and awnsers. based on compliance level of the location persons may answer these questions. So in my opinion, youre location-table will have an attribute 'compliance_level' and in the question table also an attribute, like minimum compliance level. so this could be an criteria for showing questions or not.
To register the answers done bij a person, also an awnser-table will be nesseccary, with relation to the specific question and the personId who answer it. Because of the 1 to 1 relation between person and location, this information does not have to be registerd with the anwsers.
so in short:
5 tables =>
Person (id, name, locationId, etc. )
Location (id, locationName, complianceLevel)
Question(id, quetion, minCompliance)
Anwser(id, questionId, personId, answerId)
In order to create these forms, i guess a master-detail form will be in place. where for one master (person in this case), the details can be shwon (question) in a tabular form with input for the answers.
hope this will help!

Best use of framework events in application architecture

Hello,
I apologize in advance if this is not the appropriate forum to be posting about Flex framework questions. I considered the Cairngorm forum, but thought the question applied more broadly to all flex frameworks. That, and it seems that the Cairngorm forum isn't really very active.
My question is about using frameworks for application architecture. Reading the "Introducing Cairngorm" document, I see that it specifically says that Cairngorm events are just those events that will handle business logic (things like grabbing data from a server, committing data to a server, etc). So then, how does a view interact with a controller when changing state?
Let's say I have two or three different views of the same data and I have a buttonbar to switch to the view I want. Is it then typical to dispatch a Cairngorm (or Mate/Swiz/Pure MVC, etc..) event to the controller to change the view state of the application? Does this effectively mean that for every button a user can click on, we'll have an event and a command associated with that event to perform some change of state or business logic? With a moderately complicated application, with several different screens, a few forms, a couple of lookups, i.e. lots of buttons for user input, that seems like an awfully huge number of events/commands...? Or do you dispatch a regular old flash Event to handle this? Or does the view data bind to the model to change the view state?
Obviously there's never any single correct answer to application architecture questions, but I'd like to know if there's any general best practices that I should follow. I don't want to under-architect OR over-architect my app. I'm new to Flex programming and would like not to code something egregiously ugly.
Thanks,
Cory

Hi,
Consider this, there is no such thing as an enterprise level RIA, the whole concept behind thin client was to restrict the enterprise requirements to the backend, that being said if we assume that a flex application is specifically for the client end and can maintain its own state and that MVC frameworks are more about enterprise solutions then the whole framework argument becomes what it is, academic BS.
<start rant>
Its really simply, in half a century nothing has changed, you have rules and requirements(model), you have access to that(view) and you wrap it up as a program/application(controller) so why do you need convoluted multilayer abstraction of functionality to make things work ? maybe so those that can't get a real development job can run around and preach at conferences, how else could they feed their adopted kids.
So all those nice buzzwords, design patterns(the new age terminology for modular architecture), model/view/controller, borg coding(resistance is futile) is all very fine if you want to act smart but producing quality code actually means you are smart. As you may have guessed I am not a strong proponent of MVC frameworks, and I don't even need to get into the argument that everytime a 'framework' expert gets control of a project that isn't done in their MVC poison of choice it gets a rewrite, clients really love those associated costs and retesting requirements.
</end rant>
You only need 1 framework for flex and thats the flex framework.
Have a read this blog, the section on MVC and Flex is very interesting if not overly polite.
http://www.herrodius.com/blog/216
David

Database design for Help Desk application.

Hello does any one know
Database design for Help Desk application.
ERD
Business rules and features
?

The best way to approach a database design is to write a
specification for the application. Document what processes the help
desk technicians will do. In the process, identify what pieces of
information they work with. When you have the complete
specification written, you can then begin grouping the pieces of
information they work with together. For example, a ticket may have
a number, status, priority and a person to whom it is assigned. The
person to whom the ticket is assigned will have a name, phone
number, e-mail address and a list of technical skills.
So in this overly-simplified example, we could have a table
that contains ticket information, a table that has information
about technicians and a table of skills. Then ask your self
questions like "Can one ticket be handled by more than one
technician?" "Can one technician handle more than one ticket?" Can
a technician have more than one skill?" In this way, you can begin
seeing the one-to-one, one-to-many and many-to-many relationships
that exist.

Architecture of database heavy application

A program I'm currently designing is extremely database heavy, almost anything the user does will alter the database, or read from it. Now I have one interface which defines all these operations, and one database class which implements this.
The result is that that class is huge, it contains logic for creating users, editing them, creating events, showing events to the user, editing, adding friends, adding items to a product, ....
On the one hand I can argue this does not violate SRP, because the whole use is database communication. On the other hand, this is a lot of code for one class.
Are there any design patterns that solve this, or is this acceptable?

Moderators,
Please look closely, I have already pointed it and you would find that ALL answers which Takken go is from Engsoochean. This is highly not possible its clear favoritism. There are couple of users who are marking ONLY HIS ANSWER and ONLY VOTING HIS POST helpful.
I am not saying answer is incorrect and question is not relevant to Database design.
I have ONLY UNMARKED the answer as I want other moderators to have a look and then they can mark the answer.
Please mark this reply as answer if it solved your issue or vote as helpful if it helped so that other forum members can benefit from it
My Technet Wiki Article
MVP

SIMPLE Database Design Problem !

Mapping is a big problem for many complex applications.
So what happens if we put all the tables into one table called ENTITY?
I have more than 300 attributeTypes.And there will be lots of null values in the records of that single table as every entityType uses the same table.
Other than wasting space if I put a clustered index on my entityType coloumn in that table.What kind of performance penalties to I get?
Definition of the table
ENTITY
EntityID > uniqueidentifier
EntityType > Tells the entityTypeName
Name >
LastName >
CompanyName > 300 attributeTypes
OppurtunityPeriod >
PS:There is also another table called RELATION that points the relations between entities.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
check the coloumn with WHERE _entityType='PERSON'
as there is is clustered index on entityType...there
is NO performance decrease.
there is also a clustered index on RELATION table on
relationType
when we say WHERE _entityType ='PERSON' or
WHERE relationType='CONTACTMECHANISM'.
it scans the clustered index first.it acts like a
table as it is physically ordered.I was thinking in terms of using several conditions in the same select, such as
WHERE _entityType ='PERSON'
AND LastName LIKE 'A%' In your case you have to use at least two indices, and since your clustered index comes first ...
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Have you ever thought of using constraints in your
modell? How would you realize those?
...in fact we did.We have arranged the generic object
model in an object database.The knowledge information
is held in the object database.So your relational database is used only as a "simple" storage, everything has go through your object database.
But the data schema is held in the RDBMS with code
generation that creates a schema to hold data.If you think that this approach makes sense, why not.
But in able to have a efficent mapping and a good
performance we have thought about building only one
table.The problem is we know we are losing some space
but the thing is harddisk is much cheaper than RAM
and CPU.So our trade off concerated on the storage
cost.But I still wonder if there is a point that I
have missed in terms performance?Just test your approach by using sufficiently data - only you know how many records you have to store in your modell.
PS: it is not wise effective using generic object
models also in object databases as CPU cost is a lot
when u are holding the data.I don't know if I'd have taken your approach - using two database systems to hold data and business logic.
PS2: RDBMS is a value based system where object
databases are identity based.we are trying to be in
the gray area of both worlds.Like I wrote: if your approach works and scales to the required size, why not? I would assume that you did a load test with your approach.
What I would question though is that your discussing a "SIMPLE Database Design" problem. I don't see anything simple in your approach when it comes to implementation.
C.

DataBase Design For InvoiceSystems

Sir I am doing my Final Year B.sc(Comp.sci), I am having my Oracle Project to do things.
I just wan't a Detailed DataBase Design for
Invoice Systems
Please Could you help me in terms of DataBase Design......

The best way to approach a database design is to write a
specification for the application. Document what processes the help
desk technicians will do. In the process, identify what pieces of
information they work with. When you have the complete
specification written, you can then begin grouping the pieces of
information they work with together. For example, a ticket may have
a number, status, priority and a person to whom it is assigned. The
person to whom the ticket is assigned will have a name, phone
number, e-mail address and a list of technical skills.
So in this overly-simplified example, we could have a table
that contains ticket information, a table that has information
about technicians and a table of skills. Then ask your self
questions like "Can one ticket be handled by more than one
technician?" "Can one technician handle more than one ticket?" Can
a technician have more than one skill?" In this way, you can begin
seeing the one-to-one, one-to-many and many-to-many relationships
that exist.

Database design for DSS

Hello All
I have to design database for a DSS.
It is basically a MIS project which will be used for reporting purposes
Can anyone please tell me what are the considerations to be made
while designing for such a system.
Any documents or web links will be of great help
Thanks in advance
Ashwin N.

The best way to approach a database design is to write a
specification for the application. Document what processes the help
desk technicians will do. In the process, identify what pieces of
information they work with. When you have the complete
specification written, you can then begin grouping the pieces of
information they work with together. For example, a ticket may have
a number, status, priority and a person to whom it is assigned. The
person to whom the ticket is assigned will have a name, phone
number, e-mail address and a list of technical skills.
So in this overly-simplified example, we could have a table
that contains ticket information, a table that has information
about technicians and a table of skills. Then ask your self
questions like "Can one ticket be handled by more than one
technician?" "Can one technician handle more than one ticket?" Can
a technician have more than one skill?" In this way, you can begin
seeing the one-to-one, one-to-many and many-to-many relationships
that exist.

BPEL/ESB - Architecture question

Folks,
I would like to ask a simple architecture question;
We have to invoke a partner web services which are rpc/encoded from SOA suite 10.1.3.3. Here the role of SOA suite is simply to facilitate communication between an internal application and partner services. As a result SOA suite doesn't have any processing logic. The flow is simply:
1) Internal application invokes SOA suite service (wrapper around partner service) and result is processed.
2) SOA suite translates the incoming message and communicates with partner service and returns response to internal application.
Please note that at this point there is no plan to move all processing logic from internal application to SOA suite. Based on the above details I would like get some recommedation on what technology/solution from SOA suite is more efficient to facilate this communication.
Thanks in advance,
Ranjith

You can go through the design pattern called Channel Adapter.
Here is how you should design - Processing logic remains in the application.. however, you have to design and build a channel adapter as a BPEL process. The channel adapter does the transformation of your input into the web services specific format and invoke the endpoint. You need this channel adapter if your internal application doesn't have the capability to make webservice calls.
Hope this helps.

Requirements for database design and installation

Hi,
As a database administrator, how to find out whether the database is design and installed properly?
Can you please what would be the requirements to be considered towards the databse design for application developer ?
thanks heaps !!!!

Mohamed ELAzab wrote:
regarding that the number of execution is the main thing that affects the performance i said that already above " the application executed it 30 000" but you didn't read my answer correctly. I did not respond to that "answer" of yours as it was not part of your posting that I responded too. In your response, which I quoted, talked about non-sharable SQL retrieving 20 rows and after 3 years it retrieving a million rows. This has no bearing on whether the SQL is sharable or not.
I don't agree with you regarding that the design is not being done regarding considering the performance bottlenecks.So you decide on what the bottlenecks are up front, and then use these as database design considerations? I fail to see any logic or merit in such an approach.
i want to let you know that we in the telecoms environment have many problems in our databases because the people who designed those applications didn't take performance in consideration.I understand too well - and it is not that they did not take performance into consideration when designing the database, it is because the design is just plain wrong from the start.
You do not need to consider amount of memory available, number and speed of CPUs, bandwidth and speed of the I/O system, in order to design a database. These have no relevance at all during the design phase. Especially as the h/w that will run the design in production in a year's time can be drastically different from the h/w that will be used today.
No, instead you use a proper and correct design methodology and data modeling approach. Why? Because such a design by its very nature will make optimal use of h/w resources and will provide data integrity, scalability and performance.
Again i think design of the database application must take database performance bottlenecks in consideration like application which doesn't use bind variables if they took into consideration to avoid that it will help the DBA in the future but unfortunately most people doesn't do that. And as I said - using bind variables or not has absolutely nothing to do with the basic question asked in this thread: "+what are the requirements of database design+".
How does using/not using bind variables influence the design of a table? Determine whether an entity is in 3NF? What the unique identidiers are for an entity? These are the design considerations for a database.. not bind variables.
Yes, SQLs not using bind variables can cause performance problems. Not paying the electricity bill can cause a power outage for the database server. So what? These issues have no relevance to database design.

Database design to support parameterised interface with MS Excel

Hi, I am a novice user of SQL Server and would like some advice on how to solve a problem I have. (I hope I have chosen the correct forum to post this question)
I have created a SQL Server 2012 database that comprises approx 10 base tables, with a further 40+ views that either summarise the base table data in various ways, or build upon other views to create more complex data sets (upto 4 levels of view).
I then use EXCEL to create a dashboard that has multiple pivot table data connections to the various views.
The users can then use standard excel features - slicers etc to interrogate the various metrics.
The underlying database holds a single days worth of information, but I would like to extend this to cover multiple days worth of data, with the excel spreadsheet having a cell that defines the date for which information is to
be retrieved.(The underlying data tables would need to be extended to have a date field)
I can see how the excel connection string can be modified to filter the results such that a column value matches the date field,
but how can this date value be passed down through all the views to ensure that information from base tables is restricted for the specied date, rather than the final results set being passed back to excel - I would rather not have the server resolve the views
for the complete data set.
I considered parameterisation of views, but I dont believe views support parameters, I also considered stored procedures, but I dont believe that stored procedures allow result sets to be used as pseudo tables.
What other options do I have, or have I failed to grasp the way SQL server creates its execution plans and simply having the filter at the top level will ensure the result set is minimised at the lower level? (I dont really want the time taken for the dashboard
refresh to increase - it currently takes approx 45 seconds following SQL Server Engine Tuning Advisor recommendations)
As an example of 3 of the views,
Table A has a row per system event (30,000+ per day), each event having an identity, a TYPE eg Arrival or Departure, with a time of event, and a planned time for the event (a specified identity will have a sequence of Arrival and Departure events)
View A compares seperate rows to determine how long between the Arrival and Departure events for an identity
View B compares seperate rows to determine how long between planned Arrival and Departure events for an identity
View C uses View A and view B to provide the variance between actual and planned
Excel dashboard has graphs showing information retrieved from Views A, B and C. The dashboard is only likely to need to query a single days worth of information.
Thanks for your time.

You are posting in the database design forum but it seems to me that you have 2 separate but highly dependent issues - neither of which is really database design related at this point. Rather you have an user interface issue and an database programmability
issue. Those I cannot really address since much of that discussion requires knowledge of your users, how they interface with the database, what they use the data for, etc. In addition, it seems that Excel is the primary interface for your users
- so it may be that you should post your question to an excel forum.
However, I do have some comments. First, views based on views is generally a bad approach. Absent the intention of indexing (i.e., materializing) the views, the db engine does nothing different for a view than it does for any ad-hoc query.
Unfortunately, the additional layering of logic can impede the effectiveness of the optimizer. The more complex your views become and the deeper the layering, the greater the chance that you befuddle the optimizer.
I would rather not have the server resolve the views for the complete data set
I don't understand the above statement but it scares me. IMO, you DO want the server to do as much work as possible since it is closest to the data and has (or should have) the resources to access and manipulate the data and generate the desired
results. You DON'T want to move all the raw data involved in a query over the network and into the client machine's storage (memory or disk) and then attempt to compute the desired values.
I considered parameterisation of views, but I dont believe views support parameters, I also considered stored procedures, but I dont believe that stored procedures allow result sets to be used as pseudo tables.
Correct on the first point, though there is such a thing as a TVF which is similar in effect. Before you go down that path, let's address the second statement. I don't understand that last bit about "used as pseudo tables" but that sounds more
like an Excel issue (or maybe an assumption). You can execute a stored procedure and use/access the resultset of this procedure in Excel, so I'm not certain what your concern is. User simplicity perhaps? Maybe just a terminology issue? Stored
procedures are something I would highly encourage for a number of reasons. Since you refer to pivoting specifically, I'll point out that sql server natively supports that function (though perhaps not in the same way/degree Excel does). It
is rather complex tsql - and this is one reason to advocate for stored procedures. Separate the structure of the raw data from the user.
(I dont really want the time taken for the dashboard refresh to increase - it currently takes approx 45 seconds following SQL Server Engine Tuning Advisor recommendations)
DTA has its limitations. What it doesn't do is evaluate the "model" - which is where you might have more significant issues. Tuning your queries and indexing your tables will only go so far to compensate for a poorly designed schema (not that
yours is - just a generalization). I did want to point out that your refresh process involves many factors - the time to generate a resultset in the server (including plan compilation, loading the data from disk, etc.), transmitting that data over the
network, receiving and storing the resultset in the client application, manipulating the resultset into the desired form/format), and then updating the display. Given that, you need to know how much time is spent in each part of that process - no sense
wasting time optimizing the smallest time consumer.
So now to your sample table - Table A. First, I'll give you my opinion of a flawed approach. Your table records separate facts about an entity as multiple rows. Such an approach is generally a schema issue for a number of reasons.
It requires that you outer join in some fashion to get all the information about one thing into a single row - that is why you have a view to compare rows and generate a time interval between arrival and departure. I'll take this a step further and assume
that your schema/code likely has an assumption built into it - specifically that a "thing" will have no more than 2 rows and that there will only be one row with type "arrival" and one row with type "departure". Violate that assumption and things begin to
fall apart.  If you have control over this schema, then I suggest you consider changing it. Store all the facts about a single entity in a single row.  Given the frequency that I see this pattern, I'll guess that you
cannot. So let's move on.
30 thousand rows is tiny, so your current volume is negligible. You still need to optimize your tables based on usage, so you need to address that first. How is the data populated currently? Is it done once as a batch?  Is it
done throughout the day - and in what fashion (inserts vs updates vs deletes)? You only store one day of data - so how do you accomplish that specifically?  Do you purge all data overnight and re-populate? What indexes
have you defined? Do all tables have a clustered index or are some (most?) of them heaps?   OTOH, I'm going to guess that the database is at most a minimal issue now and that most of your concerns are better addressed at the user interface
and how it accesses your database. Perhaps now is a good time to step back and reconsider your approach to providing information to the users. Perhaps there is a better solution - but that requires an understanding of your users, the skillset of
everyone involved, what you have to work with, etc. Maybe just some advanced excel training? I can't really say and it might be a better question for a different forum.
One last comment - "identity" has a special meaning in sql server (and most database engines I'm guessing). So when you refer to identity, do you refer to an identity column or the logical identity (i.e., natural key) for the "thing" that Table A is
attempting to model?

Can JWS do this...? Architecture question

Hi,
I'm designing the architecture for a school board that is moving a COBOL system to a Java App Server system. Within the system there are approx 180 'Modules' - each module being a set of screens that allow a user to accomplish a task. For example, the Teacher Grading module allows a teacher to access their student records and maintain the student's grades.
I'm looking to use JWS for deployment of the front end but am unsure if JWS will support the framework I want to put in place.
From a UI perspective, as there are so many modules in the system I want to design the architecture in a way that allows each module to plug in to the existing framework.
The front end would consist of a container application that would house each module in a sort of tabbed view. As each module is added to the system so the user would see a new tab in the UI that housed the new module (depending on whether the users had permissions to access the module).
So the front end container would display the modules that the user can access, adding new ones as they are defined.
Question:
Is the server's JNLP file for the application static? If it was ammended to include new jars would this cause problems on the Client side post initial installation, or would it take it in it's stride and just upload the new jars as required?
What I want to do:
I was hoping that I could just ammend the JNLP file on the server to include the new Module (jar file), the Container app could then just get a list of class names from the App server that were applicable to the User. The Container app could then instantiate the class objects and the JWS would automatically upload jars any that were missing (using lazy loading), and subsequently add the new Module( jar) to it's list of versioned jars to update when required.
Question:
Is this possible to do using JWS?
Another possiblity:
1) Main application Container gets installed using JWS
2) User starts app and signs on
3) Container talks to App Server and determines which Modules the User has permissions to use
4) Container downloads missing or new Modules - jar files (maybe using javax.jnlp.DownloadService?)
5) Want JWS to subsequently evaluate downloaded Modules (and main app) for any updates - though this would happen at step 2.
Question:
Would an individual Module's jar file/s need to be referenced in the JNLP file to download it using javax.jnlp.DownloadService? I am thinking it would.
Things to note - it is not possible to define the app with all 180 Modules embedded as it may take years to recode all 180 COBOL Modules in Java. and the system it being implemented iteratively. Also few, if any users will have access to all 180 Modules. Users are part of Groups (Teachers, Superintendants, Subtitutes etc) and each Group only has access to a certain set of screens (Modules).
Any advice would be appreciated, as I would like to be aware of any potential problems before I define the architecture.
cheers
Ray

You are completely free to dynamically generate the JNLP file if you wish via a regular Java servlet. In fact Sun has available a simple servlet called JnlpDownloadServlet which you'll find in the jnlp-servlet.jar file in your jdk installation. So you could create the servlet and pass arguments to it giving the user id and it could generate it with the modules that this user has access to. You would then probably also generate arguments passed to the main() function which would tell your app what classes (modules) to load into your app.
The disadvantage of this approach is that your server has to keep track of what modules this user can use, and he would probably have to use the web site and another servlet to configure it. (Assuming the user has any control over what modules he can access).
However there may be a better way for you to proceed. If you create a static JNLP file that contains ALL the modules but with the download="lazy" option, then all modules will be in the JNLP but not downloaded unless necessary.
Then you can download the bits explicitly you want to use. (The DownloadService class) will tell you how to do this.... http://java.sun.com/products/javawebstart/docs/javadoc/index.html
You will need to have all the modules listed in the JNLP file. Whenever a user starts up the app it will refresh their copy of the JNLP file. Pass the list of available modules to the main() function within the JNLP file so that the app knows they are there.
If necessary have some arguments that indicate permissions on the modules within the JNLP file that are passed to main(). (e.g. --module=mymod1.jar,perm=teachers,students )
You may want to create a ClassLoader that accesses that jar file directly (passing in the URL)... (once it is downloaded via DownloadService) and loading information directly from each jar. e.g. have an info.properties file in the "root directory" of every jar file that explains what the entry point or points are for this module. That avoids having to pass even more info in the JNLP file (e.g. --entryPoint=com.foo.MyModule1). or else having some guessable naming scheme for classes. That is a good thing at least for entry points so that the module is completely self-contained describing its own entry points. That is an approach I've used before. But you wouldn't use it for permissions, because then you would have to download it before you could tell if you need it.
Now the application itself can manage its own modules and resources using whatever criteria you desire. (You could even give the user some control). If all your modules have a standard interface for launching them, you can dynamically load those classes on demand. Use DownloadService to download the jar for that module, and then use Class.forName() to access the entry point for the module. Use the java.util.prefs.Preferences class if you need to keep track of anything on the client side about modules.
If it were me, I'd have the code be able to work without webstart as well which is easier for local debugging. That shouldn't be a problem.

DataBase Design For Inventory Systems

Sir I am doing my Final Year B.sc(Comp.sci), I am having my Oracle Project to do things.
I just wan't a Detailed DataBase Design for
Inventory Systems
Please Could you help me in terms of DataBase Design......

The best way to approach a database design is to write a
specification for the application. Document what processes the help
desk technicians will do. In the process, identify what pieces of
information they work with. When you have the complete
specification written, you can then begin grouping the pieces of
information they work with together. For example, a ticket may have
a number, status, priority and a person to whom it is assigned. The
person to whom the ticket is assigned will have a name, phone
number, e-mail address and a list of technical skills.
So in this overly-simplified example, we could have a table
that contains ticket information, a table that has information
about technicians and a table of skills. Then ask your self
questions like "Can one ticket be handled by more than one
technician?" "Can one technician handle more than one ticket?" Can
a technician have more than one skill?" In this way, you can begin
seeing the one-to-one, one-to-many and many-to-many relationships
that exist.

Limitation in using sql *plus as a database for applications

dear experts;
I would like to know all, what are some of the major limitations in using sql*plus as your database in designing application besides the fact the user-interface is not friendly enough..and google is not producing relevant answers to my questions by the way unfortunately

user13328581 wrote:
I know about the drivers, I just need an IDE very similar to PL/SQL developer that will give me an opportunity to create the tables and their relationships and perform other DDL tasks that is why initially i was just wondering whether it is okay to utilize sql*plus for all that...SQLPlus can process any valid sql statement. Actually, it will pass anything that is not a sqlplus command to the database to be processed. The database will process any valid sql statement and pass the result back to the client to do with as the client sees fit - the client being sqlplus in this case.
Which is exactly what SQL Developer does. You say you want something "very similar to PL/SQL developer ". Why not SQL Developer itself?
It sounds like you continue to confuse the database with the client application. ("what are some of the major limitations in using sql*plus as your database ...", "I need an oracle database which can be integrated with visual studio ")
The database has no user interface at all. It accepts connection requests from clients, processes sql statements (or pl/sql blocks) passed from those clients and returns results to those clients. Those clients could be sqlplus, SQL Developer, Toad, Visual Basic, Access, Excel, or any number of other products -- all connecting to the same database at the same time, to do whatever they are programmed to do. You want to develop an app in visual studio? Be my guest. You want to use SQL Developer to create the tables, etc, needed by the app? Go right ahead. They are not mutually exclusive. You want to use sqlplus as well? Go ahead, it's the same database, just a different client app.

Suggestion: Create a Database Design Forum

I recommend the creation of a new forum dealing exclusively with database design questions, such as setting Primary Keys, Unique constraints, Check constraints, Indexes, schema-creation scripts, etc. There is no forum devoted exclusively to this topic now and I feel it would be very helpful to the user community. It would certainly make searching for answers to design questions much easier.

Billy Verreynne wrote:
Prohan wrote:
I don't agree there.
1. How to create a relational model certainly IS relevant to Oracle, which is a RELATIONAL DBMS.Oracle also supports data warehousing (star schema designs), network/hierarchical designs, object-relational designs - or pretty much any data model that you may come up with. Calling it just a relational DBMS is incorrect.
2. Your point that logical models are independent of specific technology is correct. What you're missing is that if a specific technology makes use of a certain foundational body of knowledge, that knowledge is a legitimate topic for a forum whose users use that specific technology.That is putting the cart in front of the horse IMO.
I would rather see data modeling and logical database design being done in a way that is untainted with specific vendor implementations and technology used. There needs to be a clear line dividing the design from the implementation. If not, then design decisions can (and will) be made based not on the correct logical data modeling principles, but whether it can be "handled" by the technology. A design that is tainted like that, will always be less than optimal (especially as technology is continually evolving and changing).
An OTN forum for database design will invariable be tainted with Oracle technology - and instead of learning sound data modeling fundamentals, a warped view of data modeling will be conveyed. Where doing abc will be acceptable (when it is not), because Oracle has feature xyz that can make the flawed design work (in a fashion).Excellent points. I think (or at least hope) such a forum would attract some number of pure theorists to straighten out the view. This might make for a lively forum, and might actually influence the real products, and might even get the cart on the right side of the horse.
Hmmm, I guess I do sound hopelessly optimistic.

Database Design/Application architecture question

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