Tuesday 28 January 2014

Note: These are  extracted notes
Modern software development has been more automated by tools or concepts. This enables developer to pay attention to complexity that needs only human brains to handle. ORM is one of them. It automates database transactions, queries and thus reduces coding substantially. Several generic queries are generated implicitly by ORM tools and complex queries and their code also to the great extent are easily developed. ORM reduces development time and efforts.
Object-relational mapping (ORM) is a technology that uses  a metadata descriptor.
It connects application  to a relational database. The similarity between database and object in OOPS is both have data structure that remains same for all instances (rows). So class written any Object oriented language can be mapped to any table in relational database. Object code is written in object-oriented programming (OOP) languages such as Java or C#. ORM converts data between type systems that are unable to coexist within relational databases and OOP languages.
Object-relational mapping (ORM, O/RM, and O/R mapping) in computer software is a programming technique for converting data between incompatible type systems in object-oriented programming languages. This creates, in effect, a "virtual object database" that can be used from within the programming language. There are both free and commercial packages available that perform object-relational mapping, although some programmers opt to create their own ORM tools.
ORM resolves the object code and relational database mismatch with three approaches: bottom up, top-down and meet in the middle. Each approach has its share of benefits and drawbacks. When selecting the best software solution, developers must fully understand the environment and design requirements. 
In addition to the data access technique, ORM's benefits also include:
  • Simplified development because it automates object-to-table and table-to-object conversion, resulting in lower development and maintenance costs
  • Less code compared to embedded SQL and handwritten stored procedures
  • Transparent object caching in the application tier, improving system performance
  • An optimized solution making an application faster and easier to maintain
  • ORM’s emergence in multiple application development has created disagreement among experts. Key concerns are that ORM does not perform well and that stored procedures might be a better solution. In addition, ORM dependence may result in poorly-designed databases in certain circumstances.


Object Relational Mapping: Frameworks and Advantages

ORM (Object Relational Mapping) wraps your tables or stored procedures in classes in your programming language, so that instead of writing SQL statements to interact with your database, you use methods and properties of objects.

There are a lot of frameworks available for implementing ORM (Object Relational Mapping) in different programming languages.

Based on abstraction, ORM (Object Relational Mapping) manages the mapping details between a set of objects and underlying relational databases, XML repositories or other data sources and sinks, while simultaneously hiding the often changing details of related interfaces from developers and the code they create.


ORM (Object Relational Mapping) hides and encapsulates change in the data source itself, so that when data sources or their APIs change, only ORM needs to change to keep up—not the applications that use ORM to insulate themselves from this kind of effort. This capacity lets developers take advantage of new classes as they become available and also makes it easy to extend ORM-based applications. In many cases, ORM changes can incorporate new technology and capability without requiring changes to the code for related applications.
Gurupurnima, 22-July-2013                                                                    -Divya Jadhav

Usually we do not express explicitly our veneration for some one. It does reflect implicitly in action.  It is so inner and natural feeling that it should really not have any decoration of words. Such respect for some one at the bottom of heart so personal that one feels it might be devaluated by artificial expression. My health and family tragedy had kept me away from this. But now I wish to express my 20 year-old feelings into words.  Situation needs me to do this for a common man who did extra ordinary contribution to my life during these two decades.
This page belongs to my teacher, my mentor, my guru Mahesh Kulkarni.   I can go ahead, without hesitation, to say that if his (Mahesh sir’s) timely motivations were not there, his follow ups were not there perhaps I and my husband could not have achieved what we have today.  I remember those days of 1992 when Mahesh sir used to teach high school as well as degree college students. In fact he was the in-charge of our computer centre. His motivational blasting speech has been called as “injection” ever since that time. It so happened that some of us were aware of his career inspirational talks in personal meetings. Those boys requested him to “motivate us” when we were about to about to face our final year commerce exams. He hesitated by his usual words “I am a small person” and then agreed. I will never forget that evening of December 1992 which changed my life and so is claimed by my husband Sudhir. Mahesh had used all his skills of English, Hindi, and Sanskrit and taken us on ride from birth to death to wake us up. Most of us were shaken up to plan vigorously for better and better career and overall life. Whenever we used to praise him, he used to say I am a small person like a small particle in this universe. Today I understand the term “god particle”.
                                                

His motivations, love for nations, affection towards students and views about god and culture. I have huge value for this in my life. We met several time after that day and he kept reminding us for every day improvement in personality, character and career. Although he only laid foundation of my software career but I have always seen fatherly affection towards all boys and girls for years together. We stayed together in Dubai.  But my father had allowed me to go to attend corporate training only because he was there.  Our trust on Mahesh sir has never shaken and will remain untouched forever.
Whenever I have seen Mahesh Sir, I have found him feeling uneasy and sad not because of his personal issues, but due to social and national issues. He would spend hours to talk about the national problems and share his views with us. I remember during those days Punjab issue, communalism used to be his often talked subjects. Many of us have learned to be proud of India and Indian culture after our talks with him.  Yes he is a common man. I know he does not have those leadership talents or name, and fame to take and solve national problems but the spirit patriotism he might have ignited in several minds is found rare.
I met him in 2001 after a gap of some years when I came to India. His condolences to me at the time of my mother’s death were very essential thought baggage for me. That helped me to come out of my sorrows and look at my kids. During those days he had caught one boy with porn sites and had counseled him for a very long time. Mahesh sir used his cultural values, spiritual thoughts, knowledge of psychology to save the youth. I know today he is Project Manager in Chicago.
I and my husband Sudhir started with Dbase and FoxPro programming in Sir’s class and could go up to Enterprise Java and then Sudhir became Project Manager. We both claim that God blessed us by providing such mentor in our lives. I have met people much more knowledgeable than Mahesh Kulkarni but I have not seen such affectionate guide for life time whose assets are values of life. I stop this article here else he may scold me for praising him too much. But before that I would like to share two similar things.
              This incidence is of 1992 when Mahesh sir was head of computer department. His boss had kept computer books worth Rs. 4 lakh in our computer department. Boss then removed these books from department in sir’s absence and without informing him. He shouted on his boss since he was answerable for everything that happens in centre. Instead of accepting his mistake his boss had sacked   Mahesh sir. We all his fans had then gone to head office and said we will not tolerate anything against our beloved Mahesh Sir. And then by our agitation we brought him back to his office. Today also after 21 years we wish to confirm with bond and unity that we will not tolerate any conspiracy against Mahesh Kulkarni sir. Our trust on him is untouched. Our love and regards for him are untouched forever.