Imran Haider

Lib Couldn't be found error while installing FOD Schema

2011-02-17T14:32:00.000+05:00

One of my future goals include to learn JDeveloper and ADF. So I started with Oracle by Example series (I think the best thing to learn a tool on OTN documentation). In article that I started out there was a requirement to install FOD schema. I checked and to my disappointment was unable to find this in default installation 11g. So I had to install it. I followed the link provided in the article and to my surprise it was not a simple SQL script that I required to run rather was an application that I had to run by first opening it in JDeveloper.

So I opened it up and did the necessary steps mentioned and than ran the project. The output was not good at all. It gave me the error that path to lib folder is missing. It was pointing to the root folder where I unzipped the application despite the fact that I gave the correct JDeveloper home path where necessary. I cannot believe it took three hours to fix this problem. And to my anger the error was the same that I had experienced a couple of days ago. Use of \ instead of / while giving folder paths to apache. So please use / instead of \ while giving paths in Oracle configuration (No, I know you are using Windows).

Oracle Database Firewall

2011-02-16T20:54:00.003+05:00

Oracle has recently released a new product named Oracle Database Firewall. Essentially the concept is same and that is to monitor and possibly block the unwanted connections to database (rather than OS here). However it does not block connections because it is not on network level but what it does is block invalid SQL statements. Now what is the definition of invalid SQL considering that any syntactical errors are detected by DBMS already.

Here invalid SQL does not mean the SQL that produces wrong results but here it means an SQL that is suspected to be one created from SQL injection techniques. SQL injections are pretty common and in most cases if not all they are unavoidable. There are techniques to prevent code from inadvertently executing injected statements but someway or the other they all fail to protect the data fully. But now you have database firewall. And the best thing about it is that it only works with Oracle Database but also on SQL Server, Sybase, IBM's DB2 etc.

For more information you can see this podcast from Director Security at Oracle Corp.

Apache path error on Windows

2011-02-14T13:11:00.000+05:00

I can almost remember this correctly. I have made this mistake three times. The mistake is to use \ instead of / while setting paths for apache on Windows. Whether it was setting report path parameter in configuration of Oracle AS services, or setting images path while installing APEX I have made this mistake again and again, only to waste a couple of hours of my life. The exception can be in case of report configuration because it was then when I made this mistake for the first time. The reason it happens to me only on Windows is because I copy paste the addresses from path bar of Windows explorer and we all know that Windows uses \ instead of / in paths but apache does not.

So be very very very careful (can't stress anymore) every time you configure something in apache which is installed on Windows. Even if it is necessary to copy paste address from address bar make sure to remove \ and replace it with /. The error it caused usually states that required directory or file cannot be found. So every time you see an error like this don't stress too much and do this change first. :)

Firefox out Chrome in

2011-01-19T14:48:00.002+05:00

I used and I loved Firefox for almost six years. Much of the time I did not even considered anything else but then Chrome came in. The first thing that got my attention was that it is from Google but then I was unable to leave my Firefox. I continued to use Firefox despite the fact that the Chrome was just too much appealing.

It ended last week and finally I have switched to Chrome. It's lighter, more attractive and even now it looks like that people behind Firefox has admitted the fact that Yes Chrome is better. If you are wondering what I am trying to say then just download the beta version of Firefox 4. You will be surprised if you are a fan of Firefox that actually they have copied the interface of Chrome. Same goes for IE 9 beta. I think I have found a new love.

This pretty much makes this prediction of mine true!!!

Oracle EBS – An Introduction

2010-12-04T15:24:00.003+05:00

Oracle E-business Suite is a software package that lets an organization manage the key business processes. The better way to understand it is to imagine the world without it.

Automation is the key. Companies tend to automate processes to save time, money and other resources. Usually in a world without Oracle EBS or any other ERP software for that matter, there will be department specific applications where every department would have built its own application using some technology. So in one organization there would have been tens of different applications quite possibly built in different platforms. And there is also possibility that all those applications may store same data independently thus resulting in data duplication. For example the employee information is something that most departments in an organization need. Now here is a software package, mind you one software package that does this all. That removes all those applications numbered in tens and storing same data independently without any integration. And even if there is an effort of integration which is a must have for any company that will be cumbersome. And managing all those applications with proper integration can be a nightmare with heavy budget.

Oracle EBS does this all. Manages all parts of business processes, stores data only once and makes it available to all other applications with an integration that stands out. But it is software package not just single software which it looks and behaves like. There are many applications (GL, AP, Absence, Expense etc) that are bundled into product families (Financials, HRMS, CRM etc). And this fact adds more beauty to it. This modular nature of EBS allows you to implement parts of EBS rather than whole package at once. For example it is perfectly OK if you just want to implement Financials and nothing else. And as business and need grows you can add more product families to it without any hassle and without worrying about integration issues between existing and newly implemented modules.

What’s in the Name!!! Oracle

2010-08-26T12:57:00.003+05:00

It is quite a debatable topic of what is meant by an Oracle DBA/Architect when he utters the word Oracle. It's a question that is one of the earlier confusions of a novice when he enters in Oracle world and also it's a question that creates a rift in the mind of some seasoned Oracle practitioners as well.

According to Greek Mythology Apollo was termed as the God of fine arts and reflections. To help his followers in the matters of public relations and others Apollo used to speak at its temple. Apollo chose an older woman to convey his messages to common people. The name of that woman was Pythia and she spoke through meaningless cries which were only understood by priests. Those meaningless cries were called Oracle. So every time a person needs any advice from Apollo he would go to the temple and asked for Oracle. The word Oracle means "thing of wisdom".

In modern era Oracle was the name of a project of CIA in early 70s. That project vanished pretty soon and today Oracle is something else. Inspired from Codd's twelve rules for relational model for databases Larry Ellison suggested IBM to build a DBMS that uses those twelve rules. Upon IBM's refusal Larry Ellison and Bob Miner decide to quit their jobs in IBM and work for their own. They hired a room and started to build a DBMS that used relational model of databases. They build their first version in 1980 but did not commercialize it. In 1982 the second version came and they decide to name it Oracle. Today that product is the most popular and most reliable DBMS to ever exist.

It is still amongst the most amazing things in computer world that with all the rapid progress in the software and hardware industry, after almost forty years the basic elements in database design are still Tables, Columns and Rows. It's not because of lack of innovation in database area, it's only because of the fact that those ideas from E.F. Codd were so strong that there never has been a better alternative to that. And the only person to realize the potential of these concepts in late 70s was Larry Ellison.

Now back to the question what's meant by Oracle in today's world? There are three entities that are termed as Oracle and they are Oracle Corporation (Name of the company that Larry Ellison and Bob Miner started in 1978, at that time it was known as Relational Software Inc. Named to Oracle in 1983 and is the second largest software company in the world today.), Oracle Database (The physical set of files that makes storage and retrieval of data possible) and Oracle Server (The RDBMS, the software written in C Language that retrieves and manipulates the data stored in Oracle Database). As you can see that each one of these three entities has their own unique name i.e. Oracle Corporation, Oracle Database and Oracle Server. But for ease and for sometimes for style people rarely use the complete name of all three entities and simply say Oracle. The context on which the name is pronounced determines what is meant by Oracle.

Chrome, Firefox 3.5 and IE 8

2009-07-16T19:37:00.000+06:00

I am not a web master, not even an ordinary web developer. But as an IT professional I really have deep interest in browser market. As of any writing these lines are not final words but just what I think about these products.
Chrome is relatively new in market as compared to the two others but you can’t ignore it because of one single reason and that is “it is from Google”. My personal experience with it is simply exciting. I am impressed the same way as I was when I first used Gmail. The most amazing thing about it is how light it is in use. Whether it is starting up, closing, tab switching and whatever; it is extremely light in use. I am saying this because I have Firefox on the same hardware as I have this and in certain matters like startup it is much better than Firefox. The interface is really beautiful and easy to use with minimum amount of menus and buttons which give you the maximum area of your screen for the actual website. Even the status bar only appears when it is needed, once the website is completely open it becomes transparent.
Firefox has been my personal choice for the past two years and if I am not wrong it holds the maximum market share as well. The biggest advantage that Firefox had over the others is the large members of Mozilla community backing it up and the biggest add ones collection which can change your browsing experience into much more than just surfing. Experts say that Firefox 3.5 has not come up to the expectations but still I think it has got better than ever. The speed and memory consumption has definitely improved.
When I first started using computer I was really of the point of view that internet means Internet Explorer. To use internet you must have IE. And this continued for a long time until one day I saw Opera. But I think the credit here is not for IE rather it goes to Windows. Windows is leading OS in desktop market and most people use IE just because they are used to it not because of some personal liking or disliking. I never liked IE until its most recent version 8. With light tab switching, In-private browsing, paragraph bookmarks, compatibility view, and being not as heavy as IE 7; IE 8 does carry a lot of weight. It is also the first version of IE that is built according to W3C standards. So a website designed for W3C HTML will run perfectly in IE 8; no separate development required.
So what’s my take? I have profound love for Firefox but ever since I have installed Chrome (a few days back) I have not used Firefox. Have I found a new love when it comes to internet browsing? It’s a question that I can’t answer right now. Only time will tell that whether I am switching to Chrome or staying with Firefox or may be both.

Upgrading APEX 3.1 to 3.2

2009-04-27T11:48:00.000+06:00

Oracle has recently released new version of its rapid application development tool better known as Application Express (APEX). Version number is 3.2 and its main features include security enhancements and Oracle Forms Migration. The late mentioned was a great interest for me. I did not have access to the database server on which we have APEX installed but for test purposes I used another server I had with Oracle Database 10g R2 on it. So I installed APEX 3.1 on it and after carefully reading upgrade instructions I started the upgrade. Here are the simple steps.

Backup is always good. So I backed up my current installation. To backup your APEX installation all you need to do is to backup three schemas and images directory located in HTTP Server home. As I used Export Data Pump for backup so I needed to create an Oracle directory.

SQL> create directory backup as ‘e:\oracle\backup’;

SQL> exit;

C :\> expdp backup/***@ORCL directory=backup dumpfile=apex_bkp.dmp schemas=(‘FLOWS_030000’,’FLOWS_FILES’,’APEX_PUBLIC_USER’)

Next I backed up the images directory (Location = $Oracle HTTP SERVER HOME/Apache/Apache/images). Don’t remove it to another place, just rename it to something else than images. Backup is complete.

To upgrade APEX set your current working directory to where you have extracted the APEX 3.2 zip file and start SQL*PLUS. Enter the following command.

SQL> @apexins apex30 apex30 temp /i/ ORCL

This is same as fresh install. Remember in APEX 3.2 you don’t have to specify the admin user password while running the installation script. It will take some time to upgrade and during that all you need to do is to sit back and watch (better start reading something). After it is completed it will create a new user and will update APEX metadata to 3.2. There a will be crystal look in interface of APEX which will distinguish it from previous release. Also if you want to make sure that you have done what you were planning to do then go and create a migration project. If you are given a choice between FORMS and ACCESS then it means you are successful and if there is only ACESS in drop down menu than you have done something wrong.

Remember that your old applications, workspaces and users etc will still remain intact after upgrade.

Being Nice

2009-01-19T13:05:00.002+05:00

The subject of the post is a bit misleading. This is not a morality lesson rather yet another technical post. However it is about Linux rather Oracle, so you can say change factor is there.

Process scheduling is among the most important tasks that a kernel must do in order to effectively achieve Multiprogramming. Multiprogramming is a concept that all modern operating systems implement; it allows the user of the system to run several applications at a time. However in reality there can be only one application or process that can use the CPU at any given time. The kernel of the operating system switches the CPU from one process to the other and it does so extremely quickly that the user gets the illusion that multiple processes are using the CPU at a time. The decision that which process to run at what time is very critical and kernel does this by scheduling processes. Different operating systems use different algorithms. One of the things upon which the kernel relies on in making the decision of which process to run at any given time is; Process Priority.

Process priority is a value that is given to each process which determines how much this process is important. Linux handles the process priority by setting a nice value to every process. It's a nice analogy and it means that how much a process is nice to the others. A higher nice value means lower priority (process is nice to the others) and vice versa. The administrator can set the nice value and can also change it at any time. Most Linux distributions include priority classes for more complex process scheduling but they are rarely used instead the Nice value is more common and much reliable.

From Oracle Forms to APEX

2008-11-07T09:27:00.002+05:00

Oracle Forms have a legacy of well over a decade in Oracle application development. The main reason for their popularity is their tight integration with the Oracle Database. The application development can be enormously fast when using them alongside Oracle Database. But like I said in my earlier post that the problem with Oracle development tools is that they are not up to the mark. Same applies for Forms and Reports Developer. Since 6i nothing has been done to improve them. Although Oracle has incepted a web interface starting from 9i but that does not seem to be much. It uses Java in the form of JInitiator which hangs more and works fewer. I have done quite an extensive development using Forms and Reports Developer for well over two years and still doing to a great extent. I also had to manage Oracle Application Server which is hosting applications built using these two tools. So, quite a relationship: to say the least. But as the matter of fact now a day I am sick and tired of this platform.

It seems that Oracle has also backed down from these tools or at least I haven't heard anything about these tools from Oracle news sources for a very long time. Instead Oracle is supporting a shift from Forms to Oracle ADF and JDeveloper. But problem for me is that I hate anything that has anything to do with Java. So this migration is not in my concerns. However I have made a shift and the shift is from Forms to APEX. Oracle Application Express (simply APEX) formally known as HTML DB is a web based RAD tool to build application that use Oracle Database has their data source. I used the word RAD because in my opinion application development is faster as compared to Oracle Forms and in turn to any tool used with Oracle Database. The biggest pleasure for me is less effort on interface designing and yet better attractive interface. Also according to my users it is easy to use and HTML makes it run much better in browser then Forms applications.

The thing that made me think of making this transition was PL/SQL. It is common in both. All of your knowledge of PL/SQL applies to one hundred percent here. But beware of the coding style of yours, don't repeat Forms style coding here. The problem with them is that they will not give any errors at compile time but results will not be as you might expect. For example if you have to write a small trigger in Forms to return values of an item you will be quite habitual in typing as:

Return: bind_variable;

No Begin … End block and still it is perfectly ok to write like this. It is also ok in APEX as well as for as compilation goes but it will not work. You need to rewrite it like below to work properly:

Begin

Return: bind_variable;

End;

Now it will work. In more than one ways Oracle APEX is appreciable and one must do that although it has no comparison with big Giants like .Net and J2EE.

Internet Explorer-8

2008-11-03T19:06:00.002+05:00

When it comes to Internet browsing Mozilla Firefox is the dominant force. Mostly because almost every new feature usually first appears in Firefox and then in others. It has some amazing features and add-ones that simply rock. Your browsing experience gets a whole new turn and you feel much more fun and joy. Usually these features seem to be more prominent in office rather than at home because you are much busier in office. I was, I am and will always be a great fan of Firefox because it's a love lost for me. My IT department says that you can only use Microsoft products on your PC because they are safe. Highly arguable point especially when it comes to choosing between Firefox and IE. When they first time removed Firefox I got annoyed and felt like in no man's land. I missed a lot of things among which the most important was off-course tabs. To get tabs I downloaded Internet Explorer 7 and installed it and uninstalled it after three hours. I don't know what extra features it provides but it simply fails in providing the most basic service I.e. Fast Browsing. It can't even handle Oracle Applications that run through JInitiator. I am not a fan of Java but all I know is that it has no problems with IE-6 but I tried all the things that I knew but failed to make it run on IE-7. Where is Internet Explorer-8 (topic)?

For two months I used IE-6 without any liking and disliking until one day I saw Internet Explorer-8 beta download on Microsoft website. It must be tabbed so I just jumped to it. After using it for a little while I came to realize that it has same problem while running JInitiator. For my amazement and pleasure there was a solution for the problem. The name of the solution is Compatibility View. To understand it first we need to know that what Microsoft was doing before IE-8 and what they have changed in IE-8.

The biggest complain about IE for many years was, it is not adherent to the W3C standards. So the websites designed according to W3C standards displayed shabby in IE and websites were need to designed separately for IE to target the audience that use Microsoft and IE. Starting from IE-8 Microsoft has finally changed the scheme of things; IE-8 is completely adherent to the W3C standards. Done, but what about the websites that were designed specifically for IE? Those websites will run OK on prior releases of IE but will not run properly on IE-8. This is where Compatibility View comes into play. You can turn on Compatibility View for a website that does not display well on IE-8 and IE-8 will display the website to its best using Compatibility View. You had to do this only once and after that IE-8 will recognize it automatically. So that's it I turned on Compatibility View for JInitiator websites and now they work fine until I try to close them; they never get close gracefully and you had to use Task Manager's kill process weapon. Can't figure out why this is happening.

Another very interesting feature of IE-8 is Suggested Sites. Turn Suggested Sites on to get a list of websites that are related to your current browsing session. Another one is that you can bookmark a page as well as individual paragraphs and lines inside a page. Another one is tab colors. The related tabs (a tab opened from a link in another tab) are colored same. It helps a lot in tab tracking. I think these features are new and others will be following it soon. Furthermore IE-8 now saves a session for you if you accidently lost the session due to power outage and gives you the option of reopening it next you start IE (similar to one in Firefox). And last but not in any mean least is that it is light in use while you are switching between tabs unlike its predecessor i.e. IE-7.

Welcome to Linux

2008-10-23T12:22:00.002+06:00

I am recently trying to get my hands smooth on Linux. Fortunately I found a very good book (Linux Administration Handbook) to help me out in this process. The book is not any distribution specific rather covers almost all major distributions. Well I chose Redhat Linux-4 for two reasons. First and the dominant is the availability of software and secondly I was told that it is user friendly. Normally Linux is not associated with the term User Friendly but I think otherwise. I am not an expert just a newbie but the thing I felt during this short experience of mine is that it's all matter of familiarity. We used Windows from day one and never tried Linux or UNIX not even Mac. Windows has become the trademark as for as using Computer is concerned but it is self made. There is no harm in trying others and getting familiar with other desktops. But I must admit that Windows is easier to use then Linux but Linux is not all that difficult as well if you try to use it without taking Windows in your mind. Break the psyche and that's it.

And look Linux really cares about you as well. If you are from Mac background then it has got Gnome for your ease and if your background is Windows then you have got KDE. Mainly my focus is on administration side that I will be in need of at some stage during my Oracle DBA career. And I am feeling much comfortable and fun then it is on Windows. Mainly it is because of the flexibility and power that you have in your hands while doing all that stuff. It's also known as Rootly Powers (term from the book I mentioned earlier). I am really enjoying and I will be updating my blog with some Linux stuff as well in the future.

A very good early lesson that I have learned is that Linux gives you the option of modifying system files by hand. This is lots of fun but be careful because if anything went wrong you will have yourself in series troubles and biggest of them all is there is no restart and get OK option here.

Oracle Database and its Development Tools

2008-10-22T11:49:00.002+06:00

In very simple words and in one line they are at the far shores of the river. On the bright side you have got the database with all of its miracle powers that you see Oracle proclaims about on its website. And well on the other side…………. May be I think one more time before saying anything. But I really thought about it a lot. I mean just look at the features of the Oracle Database and then look at the development tools that it had; you will definitely get confuse enough and will start thinking something else. I mean from SQL Developer to Forms Builder to Application Express; all have only one problem and that is they are not up to the task.

I wrote about SQL Developer in my earlier post and there is no need to say anything it anymore. There is nothing wrong with its features they seem to be good. But when you start it; the way it will consumes you machine's resources is too overwhelming. May be using something else then Java may solve the problem. There is nothing wrong with Forms and Reports Developer but they are too old to be used. After 6i nothing has been done to improve them; just a web interface which hangs more and works fewer; again thanks to Java. Although I am new to application express and just a couple of days ago I loved everything of it but till yesterday. Although very frequently it happens that your LOV may stop working but yesterday I discovered something that made me annoyed more then what when I get over my end-user's response. You cannot use updatable Primary keys on tables in application that you are planning to build using Oracle Application Express. Primary keys must be auto update either using a trigger or some PL/SQL function. Don't get confuse that it offers an option because that does not work. Updates will not work. There are works around on internet but in my case all of them failed. The problem is in Application Express 3.0; I don't whether it got fixed in 3.1 or not.

Oracle SQL Developer

2008-08-11T18:46:00.001+06:00

A few days back I happened to read an article published in Oracle magazine named as “Power of the Two”. The power being mentioned was of Oracle SQL Developer and Oracle Application Express together. I have already talked about the SQL Developer on the same blog but that post made me to rethink my previous decision to not to use Oracle SQL Developer. For the practice of the mentioned article I downloaded the latest release of the tool that runs with JDK. By the way I am playing and trying to learn more and more about Oracle APEX these days and this was one of the reasons why I opt to explore SQL Developer again.
As a query development tool I feel a great deal of comfort with PL/SQL Developer from “allroundautomations”. I found a few new features in this release of SQL Developer including the topic about which I was reading the article about in first place, the integration of Oracle APEX objects with SQL Developer. The other feature I liked was Database copy which allows moving schemas from one database to the other without export, import traditional approach. You can also generate a script of the entire schema via Database Export feature. Also some interface changes were good enough to make my mind of using it along side PL/SQL Developer. Especially browsing of database objects was really good and easy.
Despite from all this I think the only drawback which can be good enough to quit using this tool is that it is build using Java (as much as I understood). It is horribly heavy. If you minimize it then it will take about 5 to 10 minutes to get back normal at least on my machine that has fairly good hardware support including 1.5GB RAM. This one problem makes the use and the entire array of features that Oracle proclaims about it totally useless, at least for me if not for anybody else.

Microsoft Office 12

2008-05-28T11:56:00.002+05:00

Ever since Microsoft has released Windows Vista you may have seen that IT Gurus have un-leashed hell on Microsoft. I did the same. The reasons are quite understandable and clear for now and even Microsoft has realized it and now they have started talking about Windows 7. It is said that 90%of people or organizations that upgraded their desktops to Vista have now downgraded to XP again. Personally I am also not a fan of XP as well because in itself it is nothing as well. It is just a replica of Windows 2000 with some graphical enhancements. However I have a great deal of liking for Windows 2000. Windows XP however has the usability advantage over Vista and that is why it is still there. With Vista Microsoft also released its new Office suite (12) namely as Microsoft Office 2007.

So you are guessing it wrong, because today I am not to bash at Microsoft. Because MS Office is one of those things that I think Microsoft is really good at. Although this new release is really expensive in terms of memory and CPU usage but that's what the software's are tend to be with their new releases. I am using this office suite on Windows XP now days and did not found its interface all that difficult. Mainly I use Word, Excel and Outlook. I really don't have much time to discover its new features but one thing is there and that is with its new interface I found to be a real fun working on it. Outlook really looks amazing. As for as Excel is concerned well the thing I liked about it is listing of almost all the formulas in a separate tab. Also it has intelligence features that it provides while you type a formula. It reminds me of VS.Net which is simply awesome. And the last thing that I like the most is the ability to do blogging right from Microsoft Word. When you click on New it gives you two options of whether you want to create a Word document or a Blog Post. Well with powerful as the Word is in terms of editing I can make my blog posting much easier and much good looking.

Ora-Dim Utility

2008-05-22T18:12:00.002+05:00

Oradim is an Oracle utility that is used to manage Oracle instance. It can be used to create, edit and delete an instance. Its typical use is when you had to manually create the instance for any reason. Among the reasons is when instance gets corrupted or when you are recovering your database after a media failure. For example if you want to create an instance then open the command prompt and issue the following command.

C:\oradim –new –sid crimson –syspwd oracle

The above command will create an instance named as crimson and the password for its sys account will be oracle. Now if you want to delete an instance then issue the following command.

C:\oradim –delete –sid crimson

This command will delete the instance. I was quite used to with these commands but here is something new that I discovered a few days earlier. Oradim can be used not only to start Oracle instance but also to start the database service at operating system well. The problem that I was facing was that I had Oracle 10g installed at home for playing. Normally I turned its services off and whenever required I turn them on. Every now and then I had to go to MMC and do the specific job. That is quite hectic, isn't it? So I searched and then devised a script that will do all the stuff for me with just a single click. It looks like this:

rem Start Listener

lsnrctl start

rem Start Oracle Database

oradim -startup -sid orcl -syspwd oracle -starttype srvc, inst

rem Start EM

set ORACLE_SID=ORCL

emctl start dbconsole

This script is for Windows. It first starts the Listener and then uses Oradim to start the database service and database itself. The parameter –starttype will define what to start. In this case both will get started. (srvc=service, inst=Instance)

Now if want to shutdown all these things then here it is:

rem Stop Oracle Database

oradim -shutdown -sid orcl -syspwd oracle -shuttype srvc, inst -shutmode i

rem Stop Listener

lsnrctl stop

rem Stop EM

set ORACLE_SID=ORCL

emctl stop dbconsole

For further options just type Oradim in command prompt provided that you have Oracle installed.

Oracle on Windows

2008-05-20T19:02:00.002+05:00

Oracle and Microsoft are considered to be bitter rivals. Both are leading the software market of the world so the rivalry is understandable. But as the matter of fact both are forced to consolidate each other by their business needs. Just the hint of it, is the growing intentions of Oracle to support more and more .Net platform and Microsoft is doing vice versa as well. In this post I am not going to discuss their business policies about each other rather I will try to explain the specific Oracle architecture on Windows. Although Oracle is platform independent and most of the management tools of it run similar on every platform but of course there are differences as well. It is so because every operating system has its own way of handling resources and applications. Furthermore process and memory management are different as well.

Unlike Linux which is process based, Windows is thread based. In Windows process is not the work horse rather it is just a container to hold threads. Threads are created by the process that contains those threads. It then uses those threads for the real work. So when Oracle gets started a process initiates and then it creates the threads for the real work. So the different background processes that Oracle uses like PMON, SMON, DBWR etc are treated as threads by Windows. So you will not be able to see these processes in Task Manager, the same thing is possible in Linux. In Task Manager you will only see one process and mainly it will be named as Oracle.exe. This process will create individual threads for the working.

What this means for the DBA is to understand that when you start Oracle Database service from MMC then it does not mean that Oracle Database gets started. Although it is necessary to start the service but this does not guarantee the startup of Oracle Database. Normally when the Oracle service is on automatic start then it does both the tasks. But when you had to manually start then first you start the Oracle service and then issue startup command from SQL*PLUS while logging as sys. The first will create the Oracle process and startup command will start your instance (Oracle Background processes (individual threads on Windows) and Shared Global Area).

Gmail on Nokia 6030

2008-05-15T18:14:00.002+05:00

Well am I getting too emotional about Google or what? As the matter of fact I am and rightly so.

Nokia 6030 is a normal phone set. I am using the term normal because it does not have any latest features such as Bluetooth, Wimax etc. it supports GPRS but the look and feel is not that attractive. It uses WAP (Wireless Access Protocol) to access web pages. I just activated my GPRS just for the heck of it because I knew I will not be able to do anything useful from this handset. Just playing with it I opened my favorite Gmail. It came with a message that I can experience it much better if I can download the application from the given link. It was also stated there that this application is solely for Nokia 6030. I got excited and jumped to it immediately.

The application got downloaded within no time (size = 114KB). I opened the application and well the experience was fabulous. I kissed my handset in amusement and thought that I really got something huge thing in my hand. But then I realized that it should not be Nokia 6030 that I kiss rather it may be Gmail. I opened Yahoo and yes I was right. I told my colleagues about this and they did the same. The application size and version comes according to the capabilities of your handset. Well it is simply great. Just try it.

A Year Ago!

2008-05-12T17:04:00.002+05:00

When a human being becomes happy? We use to define happiness in many different ways. But in actual when one feels a feeling of achievement or appreciation then a strange ray of happiness surrounds him. But that does not last forever. The time passes and he gets some new desires and wants something more. This thing also helps us in being more productive but we should not forget what we already have and should not forget to thank Allah for that. Another question that arises is whether it’s the fate or one’s hard work that plays a bigger role in dictating the road. In my opinion both play the role or at least in my life both have played.

A year ago there was only one thing on my mind and that was to get an Oracle job. I always dreamed of to be an Oracle DBA but as a starter I was ready to do development. Year ago on exactly the same day as today I was in the heart of Pakistan (Lahore) for an interview for the post of Oracle Developer in a well known Oracle related firm known as Jaffer Brothers. I really heard a lot about this company and was really excited. I was not successful in getting the job however they gave me a proposition that if I can learn Oracle Reports Developer to their satisfaction then they will give the internship. For that I really worked hard. I reminded them again and again after doing my necessary preparation but they did not give a positive response. It was at the end of August that they finally replied my mails and offered me the internship. I did not even think for one second and resigned from my current job. I was about to join them in five days or so.

I thought that to be the reward of my hard work and dedication towards Oracle. But what happened in next five days was something out of blue for me. I got an interview call from Mobilink (Largest Telecommunication Firm in Pakistan) and in four days I got interviewed three times and one day before my joining in Jaffer Brothers I got call from Mobilink saying that we offer you 23,000 for the post of Oracle Developer. I call this Fate. It was among those things that come from your prayers, prayers that you receive from your loved ones and above all from the blessings of Almighty Allah.

Google, the King!

2008-05-12T12:28:00.004+05:00

Well the title of the post is huge statement especially when you talk about something as dynamic as web is. But I think and I believe that this is huge as well as it is true. Whatever Google has done in the web technologies, it has done it well and better then its competitors. Its search engine is known to the people who are not even aware of web even. And mail from Google better known as Gmail, well it simply rocks. Before Gmail I used Yahoo mail. With all due respect I found Gmail a much better option. With unlimited capacity, mail attachment of 20 MB, Ajax enabled interface, it is simply fun to use. Although similar type of options are available in other mail providers but they started it after Gmail took the initiative. That; is what makes it great.

Although my overall experience with Gmail is good enough but initially there were three simple things that made me fan of it. Those are the ability to use “.” in login name, its interface and the quickness with which it transfers large files. This last task really frustrated me when I was using Yahoo. It took hell of time to attach files and many times it just stopped giving an error message. The same thing happens with Gmail as well but not frequently. Further more and more web sites are using Google account for authentication so it adds a little more value to your Gmail account. And last but not least is iGoogle. It has some really wonderful gadgets. They will keep you updated on almost anything. It’s my homepage by the way.

The way Google has got to the top is amazing and the way it is staying up there is even more amazing and alarming for its competitors like Yahoo and Microsoft etc.

Read Carefully

2008-05-08T16:42:00.003+05:00

Frequently it happens that while reading we ignore many things. Many times it just works but we should know what we are ignoring. A couple of weeks ago I had an interview for the post of Oracle DBA. I was really excited and was pretty much confident. In the session the person who was interviewing me asked the question that what is Instance Recovery and when and why it is done. In explaining my answer I said that when the changes of a committed transaction left uncommitted due to power failure or whatever then on next startup the SMON background process does the Instance Recovery and applies the changes of the committed transactions. The very next question was then what does the commit do?

He further explained the question that when you issue the commit command and you get reply of commit completed, then why the changes are not saved for the transaction. The question confused me at first but after a couple of minutes I figured out that commit only forces the writing of redo logs back to redo log files. It does not force the DBWR to write back to database files. So it ensures the data consistency without actually writing to the data files.

The point is that I have come through this concept multiple times but just not thinking about it caused confusion in my mind, although temporarily. Just early this morning I read it again and remembered the confusion that I encountered. So the tip of the day is to read, read, and read carefully.

OTN V/S MSDN

2008-05-07T10:03:00.001+05:00

Normally I hate to say anything against Oracle. Well you may be guessing that I am against OTN. That’s exactly the case. The reason is its confusing documentation. I have found some really good things about Oracle from OTN but overall my experience with it is not at all pleasant. The things that can be explained very simply are written in an extremely difficult way. You will find bulk and massive amount of information but still you won’t be able to figure what exactly it is trying to say. However the equally good are Oracle Press Books. I have limited access to them but they are simply great. If you are interested in any Oracle Technology and you have got Oracle Press Book on that Technology then believe me you really need nothing else. But they don’t come for free.

Microsoft has always remained under series criticism and pretty much rightly so but here I will tell you two things what I love about the biggest giant of software industry. The things are named as Microsoft .Net and MSDN. Its not because of I hate Java but it is really true that C# .Net and VB.Net are amongst the very best languages of modern application development. And when you have the tool like MS Visual Studio then as a developer you are in heaven.

The other good thing is the documentation of MSDN. It is simply amazing. It rocks. You don’t even need Internet if you have it installed on your PC. Comparing MSDN and OTN is of no use as my words are saying everything. There are a lot of good things about OTN but the thing I am talking about is really confusing i.e. documentation. Oracle should try to simplify things rather then complicating. OTN can only help if you are well aware of the technicalities of under mention technology and you have to figure out some ordinary problems you face while working. I have never find it good enough to learn something from scratch.

Problems with Large Database

2008-04-30T11:35:00.001+05:00

Data growth is one of the problems that the DBA of today’s age faces. As the world moves toward the information age the amount of data is increasing significantly everyday. With massive amount of data the problems that pop up are space issues, performance issues and management issues. Not only data is increasing but it is also expanding its dimensions because people tend to know more and more now a days. Databases are designed for one solo purpose and that is data storage and manipulation. So no matter what, data is increasing or not the DBA had to tackle it somehow.

I will not talk much about the problems that the DBA faces with large databases because I have no practical experience of that. However I have the experience of working as a developer on large tables. Well the bottom line is experience counts and it counts more then anything. You have read all the stuff related to SQL and PL/SQL and you think that you can merely do anything with it. Most probably you are thinking wrong because knowing and working with tools available are both different things. I am not saying that both SQL and PL/SQL are something really difficult but when you are using them against large databases, problems will occur and you will be wondering that am I doing something wrong?

I am quoting an example of my own here to explain what I am trying to say. A few days back I got an ad-hoc query to answer. The query was to find all those Mobile numbers which are in table “Test1” suppose and are not in “Test2”. I wrote the following query for that:

SQL>select a.mobileno from test1 a where a.mobileno not in (

2 select b.mobileno from test2);

There is nothing wrong with the logic or query. The only thing wrong is that “Not In” operator is too slow to be used in the above query because I have 44 million records in table “Test1” and 10 million records in “Test2”. This query ran well over 10 hours without results. How can I do this? This question made me almost punching my head down. One of my senior colleagues from whom I have learnt a lot of SQL tricks told me the master blaster query which was as under.

SQL>select a.mobileno from test1 a, test2 b

2 where a.mobileno=b.mobileno (+) and b.mobileno is null;

I copied it pasted it and in under 5 minutes or so I got the required results. Now I use this query in so many ways to enhance performance in my applications and I rarely and I mean rarely use the “Not In” operator. The point I want to make is that you will not find this in any documentation or book because they are not meant for that. You can only learn this by experience.

Cricket! A Love Lost

2008-04-25T16:44:00.001+05:00

Since my childhood I used to love cricket. I used to watch it and I used to play as well. That love is long lost. If I had to figure out then it would be the World Cup ’99 that made me allergic of it. The cricket of Pakistan now a day is shameful. We have not an even a single world class player. Take a look at our team and you will have no desire to sit in front of your TV watching your heroes mugging around. Gone are the days when we had players like Wasim Akram, Waqar Younis, Saeed Anwar, Aamer Sohail etc who used to win matches for us. I even have some strange feelings while talking about cricket of Pakistan right now.

Bad time comes on everything. It’s not at all shameful but I think this is not simply a bad time for Pakistani cricket. When you had a president who does not know heck about cricket then what else you can expect. The problems are in wide range and the most basic of them all is that we in Pakistan have undeserving people at the top in each and every field of life and PCB is no exception. PCB has never done anything useful for the cricket. They mishandled each and every issue. The recent issue regarding Shoaib Akhtar is one prime example of that. Don’t even think for a second that I am a fan of this so called cricketer. I think the problem with him is that he made a wrong decision when he decided to be a cricketer. He should have been a model or an actor but who knows what he had done there.

This may seem a bit harsh especially considering the fact that we have cleaned sweep a series. I will not mention the team because it will generate another conspiracy. May be we should invite Holland or Zimbabwe again and then again Bangladesh so Shoaib Malik could have an unbreakable winning streak as a captain.

Experience! No Match

2008-04-23T10:17:00.000+05:00

A year ago I was really struggling for an Oracle job. I was working in a private software development firm who used .Net as the platform. My one and only dream at that time was to get an Oracle job no mater what. Even I was ready for internship of Oracle and was ready to leave the current job. All that sudden I got employed in a prestigious Organization (Mobilink) with handsome salary package and yes above all chance to work on Oracle Database. Before all this I used to study Oracle at home and really I thought about myself that I really know Oracle. As the matter of fact I do knew Oracle even before this job but one thing I was missing and that was Experience.

I used to think that what comes with experience when you have Oracle installed and running and you have good book in hand to read and practice. Then what is the problem with learning at home? Why people cry so much about having experience? Well I knew how Oracle works in background, how processes are created, how memory is used, how access is granted, how queries are processed etc. I knew all the technicalities but one thing I don’t know at that time was how to make effective use of it. How it can help me in getting job done? I got conquered only when I came in this job in a real time working of Oracle. When you practice at home you normally do this at your own. You really don’t know the importance of data, the only thing you care about is your learning perspective. Neither your database is large enough so you can have performance issues. Everything told in the books works fine. Well that usually does not happen.

Why it happens? That is a very good question. The simple answer is that every database is build for a purpose and that purpose is defined by business processes of an organization. So in order to work well with any real time database you need to understand the business process upon which the database is built. One thing we usually ignore to realize is that databases, applications etc are tools. Tools that make our job and life in turn easier. They should be used that way. Not only you will get a sign of relief but also it will increase your affection with the tool you are using. In my own case my current job has made me feel a lot better not only about myself but also about Oracle as well.