Why would I want to use Oracle Designer as opposed to simply maintaining SQL scripts and storing them in a version control system such as Subversion?
I need to decide if it is worth the effort to reverse-engineer an existing database into Designer.
It seems like it would be easier to store DDL scripts along with the application source code in subversion.
The policy of my organization is to manage all database schemas using Designer. I'm all for compliance if there is some sort of ROI, but I am not able to see how there would be any ROI by reverse-engineering an existing database into Designer.
Some benefits of using Designer:
easy to browse the table definitions, constraints etc.
graphical tools to show tables and their relationships
impact analysis tools
generation of DDL for new/altered table definitions
Whether this makes its use worthwhile depends on how much your orgnaisation makes use of these benefits. My organisation uses Designer to manage a very large (thousands of tables) database; for a smaller database the benefits may be smaller.
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I've been mandated to find out what IBM Cognos does, and I cannot find useful information on the subject apart what I can read from the IBM Website and Wikipedia.
What I'm after is some concrete examples of what Cognos can do for businesses and organisations that intend to use it.
Financial Performance Management I have no idea about but we use BI 8.4/10.1 quite a bit. The Cognos product line is actually quite large and we only really use the baseline BI stuff with Framework Manager but I'll try and help you out, based on how we use it.
Think of BI itself as an application that lets you view your data in many different ways. Now so far, it's no different to Jasper Reports or BIRT (which, despite its name, appears to provide very little BI stuff).
It does this by modelling the data (models are created with Framework Manager hence why we use it over and above the standard reporting interface) to translate raw data into business data and also relational to dimensional data if your database isn't already dimensional.
It's this business view of the data combined with the dimensionality which allows really neat manipulation within Cognos BI.
You can create reports in a truly multi-dimensional way, aggregating data in various ways across things like dates, products, geographical regions, stores, divisions and so on (depending on your dimensional setup).
All of the reports are really dynamic in that you can collapse or expand individual dimensions at will so, if for example you want to drill down on a poorly-performing state to see which individual stores in that state are causing problems, it's a simple click on an icon.
No re-querying of the data, everything just happens in very quick time. And the charts and data that can be produced are very nice.
And, on top of that, Cognos BI comes with an inbuilt query studio and report studio which allow the creation of ad-hoc reports in the exact same interface the user sees when running standard reports. No more of the Eclipse-Designer/Web-App separation that we had to endure with BIRT.
Sorry if this sounds evangelistic but we're transitioning from BIRT to Cognos BI, and the difference is substantial.
Now you may not find a lot of information outside of the IBM website, although we did find a couple of dedicated sites when we first started examining the transition. Unfortunately, I don't have them available any more since the IBM information is more than adequate.
We also make a lot of use of the IBM developerWorks forums (we use Tivoli Common Reporting which ships with the Cognos runtimes) and the microsite as well. As well as the forums, there's a whole section of developerWorks dedicated to Cognos.
A bit late, but for the benefit of anyone browsing ... Cognos BI is essentially web based reporting/ dashboarding/ analytics. Historically it connected to relational databases only; from v8.4 onwards (and moreso from v10) it also connects to OLAP cube data sources. It's designed for end user self service reporting and includes mobile as well as web connectivity.
Cognos FPM provides in-server memory OLAP cube modelling (based on the TM1 engine). A key point of difference is that it permits end-user writeback and is generally used for budgeting and 'what-if' scenario modelling. Modelling is facilitated by Rules, which enable data modification. It also scales to the max. As noted above it may be integrated to Cognos BI (as well as being stand-alone), which means that a single dashboard may include reports from both relational & OLAP sources, and provide planning. So it's very powerful.
Note that Cognos Express provides essentially the same tools for the midmarket.
A little late but in case anyone else comes here and is looking for information, I would like to enhance #paxdiablo's answer. He was talking only about Modeling and reporting tool which is the best known Cognos.
There is also a powerful tool named Metric Studio which can track in an easy way, how business is performing. This tool is IMHO the best of the Cognos Suite, since it is truly BI for the high management.
Another thing that I love from Cognos (been using it since 2004) is the administration. From an IT perspective it is way easier to make things happen in Cognos rather than any other tool I've seen (BO included).
Just to name a few: you can link row-filtering with LDAP information (e.g. roles and customers); burst reporting through cognos content or email... the possibilities are huge.
I have joined a project which has been already developed and its a legacy project with very large database and its in Java/J2EE.
I am trying to understand the Database Design & Architecture and so is there a tool available which can generate schema from the populated table representing all the constraints like foreign keys etc ?
Basically am looking for an Database Re-engineering Tool. My database is Oracle 10g.
Inputs would be highly appreciated.
I use ER/Studio and I absolutely love it for all my data modeling, reverse engineering and database design work.
http://www.embarcadero.com/products/er-studio
I should really become an ER/Studio evangelist.. but really, it is a great product.
Haven't played much with it, but Oracle has a tool included with SQL Developer: Oracle SQL Developer Data Modeler. I agree with #Raj that ER Studio is very good; I've also used ERWin. Both have the drawback of being quite pricey. For a while there was free downloads, but I see now it appears they're charging for it. Don't know how much.
I was looking for ETL tool and on google found lot about Pentaho Kettle.
I also need a Data Analyzer to run on Star Schema so that business user can play around and generate any kind of report or matrix. Again PentaHo Analyzer is looking good.
Other part of the application will be developed in java and the application should be database agnostic.
Is Pentaho good enough or there are other tools I should check.
Pentaho seems to be pretty solid, offering the whole suite of BI tools, with improved integration reportedly on the way. But...the chances are that companies wanting to go the open source route for their BI solution are also most likely to end up using open source database technology...and in that sense "database agnostic" can easily be a double-edged sword. For instance, you can develop a cube in Microsoft's Analysis Services in the comfortable knowledge that whatver MDX/XMLA your cube sends to the database will be intrepeted consistently, holding very little in the way of nasty surprises.
Compare that to the Pentaho stack, which will typically end interacting with Postgresql or Mysql. I can't vouch for how Postgresql performs in the OLAP realm, but I do know from experience that Mysql - for all its undoubted strengths - has "issues" with the types of SQL that typically crops up all over the place in an OLAP solution (you can't get far in a cube without using GROUP BY or COUNT DISTINCT). So part of what you save in licence costs will almost certainly be used to solve issues arising from the fact the Pentaho doesn't always know which database it is talking to - robbing Peter to (at least partially) pay Paul, so to speak.
Unfortunately, more info is needed. For example:
will you need to exchange data with well-known apps (Oracle Financials, Remedy, etc)? If so, you can save a ton of time & money with an ETL solution that has support for that interface already built-in.
what database products (and versions) and file types do you need to talk to?
do you need to support querying of web-services?
do you need near real-time trickling of data?
do you need rule-level auditing & counts for accounting for every single row
do you need delta processing?
what kinds of machines do you need this to run on? linux? windows? mainframe?
what kind of version control, testing and build processes will this tool have to comply with?
what kind of performance & scalability do you need?
do you mind if the database ends up driving the transformations?
do you need this to run in userspace?
do you need to run parts of it on various networks disconnected from the rest? (not uncommon for extract processes)
how many interfaces and of what complexity do you need to support?
You can spend a lot of time deploying and learning an ETL tool - only to discover that it really doesn't meet your needs very well. You're best off taking a couple of hours to figure that out first.
I've used Talend before with some success. You create your translation by chaining operations together in a graphical designer. There were definitely some WTF's and it was difficult to deal with multi-line records, but it worked well otherwise.
Talend also generates Java and you can access the ETL processes remotely. The tool is also free, although they provide enterprise training and support.
There are lots of choices. Look at BIRT, Talend and Pentaho, if you want free tools. If you want much more robustness, look at Tableau and BIRT Analytics.
I need to diagram an oracle database and I am hoping to find some good tools that are either cheap, or free.
Ideally the tool should allow me to draw the relationships between the tables, as well as remove unwanted tables from the diagram.
I already have access to MS Visual Studio 2008 as well as SSMS 2008, but I don't believe either will provide much help with oracle.
I asked this question here on serverfault, and I had several answers. However after I tried most of the tools I ran into problems with all of them.
I prefer SQL server over oracle, but I have one legacy oracle system to manage, and I am finding myself climbing an uphill battle against the numerous errors oracle throws at you on a minute by minute basis.
Have a look at TOADSoft and especially Toad Data Modeler (Toad is a very famous tool).
Another well known commercial tool is PL/SQL Developer. This is a more integrated solution (not only graphical modeling).
In both case, I didn't check the pricing but I'm sure they are worth it (and the prices must be insignificant in comparison to Oracle's license).
Like your friends over on serverfault, I had a really good experience with PowerArchitect. And it's free. . . .
Maybe I don't understand, but its only a diagram. In which any UML tool will do the job, even Visio, which should have for free or next to nothing for you, not to mention the tools in that blog. And there always pencil and paper.
Visio professional will let you reverse engineer the database schema and I've done this with Oracle before. It's actually quite good for this as you can organise the diagram into subject areas (i.e. separate pages). You can also annotate the diagrams with missing foreign keys; this is quite a useful feature for making sense of vendors' databases.
'Enterprise Architect' versions will also allow you do generate DDL from the diagrams, and you can often get VSEA2002 or VSEA2003 quite cheaply; these versions come with the EA version of Visio bundled.
I think Visio has a feature called "Reverse Engineering", with which you can specify a database connection and it will automagically draw the Diagram for you. The database connection can be anything accessible via ODBC.
(MySQL also offers such a feature in its MySQL Workbench, though I don't remember, if it was possible to specify a different database system than MySQL itself)
As long as we're mentioning pencil and paper, I'll throw in the next step up from pencil and paper. It's MS Access.
If you have MS Access on your PC, and if you can set up table links from MS access to Oracle, you can use MS Access to generate relationship diagrams, which you can then print.
You have to do a fair amount of manual work, compared to some of the pricier tools.
Set up an empty MS Access database. Then set up a table link to each of the tables in your Oracle database. Then use the Access relationship tool to draw relationship lines between each foreign key and the key it references. Classify each relationship as many to one. This creates the lines between the boxes. You can use the Access interface to drag the boxes around on the diagram until you like the visual layout. You can print the resulting diagram.
Oh, and by the way, you can create local tables to act as snapshots of some of the data, and MS queries to reload the local tables from the Oracle data. That way you can mess around with the local copies without writing to the Oracle database. You can even set up table links to a SQL server database, and move data across, bit by bit.
Depending on the complexity of your Oracle DB, and your diagramming needs, this could be enough of a tool for you.
Oracle's own SQL Developer Data Modeler has a "Free to download, free to learn, unlimited evaluation", whatever that means.
Our users have created MS-Excel spreadsheets which over time have evolved into fairly complex applications. They run their part of the business with them. But, never having been exposed to software development discipline, these spreadsheets are brittle, single point of failure, solutions.
Our development group uses Oracle primarily with Java and some other technologies. Is there a tools for conversion from MS-Excel to Oracle? At least part way so we can get a head start and not just have to reverse engineer and rewrite?
There are tools that could convert the data, but trying to converting the formulas would cause the design to be inefficient at best and unusable at worst. The difference between spreadsheets and an Oracle database are similar to the differences between a home gardener and a farmer. Both are useful on their level and some of the same principles apply, but the techniques employed are entirely different.
I suggest you examine the spreadsheets until you understand the goals they are trying to meet and then architect a system in Oracle that meets those goals using the best techniques available in Oracle. The processing will end up being quite different, but the product will be significantly better for it.
You can suck a spreadsheet into MS Access, then push it directly into Oracle as a table (or append it to an existing table). I'm sure you could write an MS Access macro to do it.
It also appears to be possible using SQL Loader from Oracle, but I've never tried that myself.
No there aren't any tools that will covert the formulas or logic. You will have to do that the hard way. You can get the data into Oracle by exporting it as a CSV and using SQL Loader to import it into the database.
You can find tools to migrate the data, but other than that you wouldn't find a tool to automatically do this, you would have to do it all manually.
Even directly copying what was there would not make sense, you were using very limited tools (Excel), you would need to re-analyze the requirements, and possibly modify them before doing anything else.