A proper physical database design is one of the most important steps that a database designer can complete to impact the overall performance of the database. When doing the physical database design it is important for the designer to understand what type of data is going to be included and how this data will be used. To better understand why this is important lets first break down a few of the basic elements that are important when completing the physical database design.
One of the most basic measures that most be examined and planned involves the smallest units within the database, the fields. The fields are derived from the simple attributes that were defined in the logical data model. A few decisions need to be made regarding each of these individual fields. First what type of data is going to be storied in them? The data type that is assigned to each field should be able to accurately represent every possible valid value, while limiting invalid values as much as possible. Special consideration should be taken for any manipulations that will be done on the data as some data types allow these manipulations a lot easier than other ones. When considering data manipulations it is important to keep in mind simple things like addition, if finding the sum of the data field’s values the data type that worked for the fields may not be large enough to support the resulting summation.
Related to the actual data type chosen, are a number of other controls that can be attached to the fields to better insure the integrity of the data. One of these controls is simple the default value that the field should take, unless another value is assigned to it. If done correct, defining a default value can be very beneficial as it coul...
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...grity can be implemented and the performance impact can be minimized. When looking at some of the more advanced design methods mentioned it is critical to understand the data and how it is used, it also doesn’t hurt to have a few tools to help you along the way.
Works Cited
Hoffer, J. (2011). Modern database management. Upper Saddle River, N.J: Prentice Hall.
Lightstone, S. (2007). Physical database design : the database professional's guide to exploiting indexes, views, storage, and more. Amsterdam Boston: Morgan Kaufmann/Elsevier.
Konig, A.C.; Nabar, S.U. (2006). ICDE '06 proceedings : 22nd International Conference on Data Engineering : 3-7 April, 2006, Atlanta, Georgia / editors, Roger S. Barga, Xiofang Zhou. Los Alamitos, Calif: IEEE Computer Society. Retrieved from: http://ieeexplore.ieee.org.portal.lib.fit.edu/stamp/stamp.jsp?tp=&arnumber=1617405
Internal schema at the internal level to describe physical storage structures and access paths, typically uses a physical data model.
This control prevents the user from entering incorrect information that could result in an erroneous value to be processed. It will also compare, if possible for that field, the value entered with a list of acceptable values; If no match exists, an error is flagged. These input control methods
Now click the “ENTER” key on your keyboard, on your computer is operating in ‘Safe Mode’.
Auto-population of blank fields so that the person inputting the data into the system doesn’t have to enter anything into the field. The field may actually have data to put information into the field once in a while and may forget to do
1. If I were to design Ben & Jerry’s data warehouse I would use several dimensions of information. The first dimension would consist of the company’s products; ice cream, frozen yogurt or merchandise. The marketing department has to know which products are selling, if Ben & Jerry’s didn’t know that their T-shirts are selling out as soon as they hit the stores, then they wouldn’t be able to take advantage of the opportunity to sell the shirts. The second dimension would consist of the different areas of sales; US, Canada, Mexico, or Europe. I am not sure if they sell their ice cream in Mexico, but with data collection they can find out if their ice cream would be a better seller in the hot climate, rather than pushing for greater distribution in Canada. The third dimension would consist of the “specifics”; where the sale was made, when the sale was made, and who purchased the product. This information can help in the design of the product to focus on the buyer; it can tailor flavors to seasons, and packaging to buyer who looks for the better-looking product. If Ben & Jerry’s could know when a season was coming to an end in a specific area, then they could forecast the need or the decline in need and speed up, or slow down distribution to those areas. The focus of the information is that it needs to be useful, and almost any information is useful.
Almost all commercial database systems available today are designed to provide a high level of performance to its users. Nonetheless, Database Performance Tuning for large volumes of data is an arduous task. Even minor changes can bring about a substantial impact (positive or negative) on the performance of the system (KOCH, 2014).
[7] Elmasri & Navathe. Fundamentals of database systems, 4th edition. Addison-Wesley, Redwood City, CA. 2004.
So how we know if our data are of good or bad quality? Following the car example, in order to answer this question we have to define which characteristics we should take into consideration and how much each of them weights. It is also important these characteristics to be measurable. A continuous research in this field providing us a great range of data attributes along with a ranking, according to their importance. In data quality literature these attributes referred as dimensions. From now on we will use this term when we talk about data quality characteristics. In chapter 2.2 we will present the data quality dimensions in detailed.
Architectural design is important to devise a proper computer-based system and allowing it to function properly. The data flow diagram designed for this essay eventually portrayed the ways through which architectural design can be used to design transform characteristics, safeguarding the computer system by incorporating and using relevant
Normalization, Integrity and Security are the important role for a DBA, Normalization helps to avoid data redundancy by reviewing data base structure at certain level. It helps to build an effective data model. Data Integrity provide some level of assurance over the information getting store and retrieved from database, DBA has to understand all DBMS features use them correctly for Data Integrity. Data Security is toughest part for DBA, auditing and multiple level security can protect data but none of them provide complete security, security can also be managed by encrypting and masking the organization data.
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A database is a structured collection of data. Data refers to the characteristics of people, things, and events. Oracle stores each data item in its own field. For example, a person's first name, date of birth, and their postal code are each stored in separate fields. The name of a field usually reflects...
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