The database system approach to data management overcomes many of the shortcomings of the old-fashioned file system approach. Another advantage of the database approach is that, because data is located in one single database, data in different physical locations need not be duplicated. The database software can interact with all the data in the database. Non duplication of data is one way of maintaining the integrity of the data. When data is allowed to be duplicated, errors can happen if one instance of the data is altered and another instance remains the same.
One of the greatest benefits of databases is that data can be shared or secured among users or applications. If there are shortcomings to database systems, its that much more powerful and sophisticated software is needed to control the database and designing the software and database can be extremely time consuming.
More extensive knowledge of how to use the database is required, thus making the database system less user friendly than traditional file systems. By following the database software development lifecycle methodology, and by using the data models, the database design ideals are fulfilled and will minimize the disadvantages. The requirements document contains a concise and non-technical summary of what data items will be stored in the database, and how the various data items relate to one another.
Taking the specifications document, the database designer models how the information is viewed by the database system and is how it is processed and conveyed to the end user. In the implementation design phase, the conceptual design is translated into a more low-level, DBMS specific design. Data models are diagrams or schemas, which are used to present the data requirements at different levels of abstraction.
The first step in the Database Development Life Cycle is to draw up a requirements document. The requirements document can then be analysed and turned into a basic data set as shown in Figure 2 which can be converted into a conceptual model. The end result of the conceptual design phase is a conceptual data model Figure 3 , which provides little information of how the database system will eventually be implemented.
The conceptual data model is simply a high-level overview of the database system. By following the above methodology, and by using the data models, these database design ideals are fulfilled. In conclusion, here are two examples of why using data models is paramount to capturing and conveying data requirements of the information system:. A database design that can change easily according to needs of the company is important, because it ensures the final database system is complete and up-to-date.
Data integrity rules are a core component of a data model. Codd, How do keys relate to ensuring that changes in database states confirm to specified rules? Well, for example, you could ensure that the primary key of an entity cannot be null. This is one way of ensuring entity integrity. If primary keys were allowed to be null, then there would be no way of ensuring that individual entities were uniquely identifiable.
So, by ensuring that keys follow certain rules, you can ensure integrity of data. Please log in with your username or email to continue. No account yet? Create an account. Edit this Article. We use cookies to make wikiHow great. By using our site, you agree to our cookie policy. Cookie Settings. Learn why people trust wikiHow. Purchase database creation software. Choose a product that is compatible with the word processing and other software tools used in the business.
This will make it easier to import or export data from other sources, making it possible to avoid entering a large amount of data into the newly created database. Determine the type of information that will be housed in the customer database. Most designs will include information such as company name, mailing address, physical address, contact name, telephone and fax numbers, and email addresses. Additional data such as information on contract terms, pricing, and notes on pending tasks associated with each client are often included in the data captured and maintained in this type of electronic resource.
Consider the possible uses for the database. Along with providing a centralized resource to retrieve important data, think in terms of what types of reports could be created using the data, or if the database is intended for use as a resource in generating mailing labels, email lists, or even lists to use in fax broadcasting. Keeping this in mind will help in determining how to name each of the fields that will house data, and ease the process of creating report formats that pull from those fields.
Organize the data fields. Create a simple template that follows a logical sequence when it comes to entering names, addresses, and other contact information. Doing so makes it easier to move from 1 field to the next with a minimum of interruption and complete the entry of a new customer record within a reasonable period of time. Set authorizations on each of the fields.
This includes identifying which fields will be included on report formats as well as which can serve as the basis for sorting or searching the database entries.
Assigning the right authorizations to each field will expedite retrieval of the right data when and as it is needed. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Create my own database system [closed] Ask Question. Asked 10 years, 1 month ago. Active 1 year, 2 months ago. Viewed k times. Improve this question. Jarrod Nettles 6, 2 2 gold badges 39 39 silver badges 45 45 bronze badges.
Xananax Xananax 1, 1 1 gold badge 12 12 silver badges 13 13 bronze badges. Why not write a compiler instead? Or even better, your own operating system? If you are really serious about writing your own database, there are a thousand and one open source databases out there: Study their source code, contribute a few patches.
Then start thinking of building your own. I knew I was going to get bashed : As I said, the purpose is to learn. I studied open-source DBs, but their codebase is too huge to get a real grasp; that's why I want to build from the ground up, beginning small and expanding until I get a real feel of how things work.
THEN it will be useful for me to deeply study what has been done. I studied open-source DBs, but their codebase is too huge : If something like redis or flockdb is too huge for you to read, I don't see how you'll cope writing or own database. YannisRizos In fairness, reading code imo is much more difficult than writing it yourself. Xananax: don't listen to the frogs crystal-reflections. Do whatever you enjoy and it is not necessary to have an objective to take pleasure in the process.
Show 18 more comments. Active Oldest Votes. There are a few generic guidelines on what to look for: Relatively small codebase, Architectural documents or at least a development blog, The database you pick should be close to what's considered generic in the family, it'd be harder to learn from if it's highly specialised. A few examples that fit: redis , flockdb , and RavenDB. Improve this answer. This is super! Even more coming from you : I'd like to accept almost each other answer but since I gotta pick one this has to be it.
I'm expecting a comment with a link to your repository when you're done : most definitely! Thanks again, to you and everyone else, this was really uplifting. And for anyone coming here looking for the same answers: I find flockDB to be the best candidate to learn, the codebase is really small, the code very readable although I don't speak scala and easy to understand.
Yannis, Btw which of the books you recommend are the ones that you have read? Xananax Sooo how is it coming along? Any repository we can look at? Show 3 more comments. The question was: However as a pragmatic developer, I am wondering what new this project is offering in a saturated market where you have quite mature alternatives like CouchDB, MongoDB, Tokyo, Redis, and many more?
If you take your pleasure in the process, don't be worry about the objective, you already won. Very nice indeed. I was on the verge of accepting this. I didn't because I thought yannis's answer to be more to the point, and more likely to help people having the same question. But this was definitely encouraging.
Thanks a lot. Yannis answer is better than mine and deserve your choice — user Add a comment. Jaydee Jaydee 2, 1 1 gold badge 17 17 silver badges 17 17 bronze badges.
Here's how I would get started: Choose your favorite language or a language that you want to improve. Create the node object or whatever is closest in your language. Figure out how to link them. Make a short list of SQL statements that you will implement first.
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