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1.How can you tell if you have a poorly designed database well it’s very easy to recognize it ha a lot of inconsistencies a lot of data redundancy and all of this results in three kinds of anomalies or problems which we’ll get to here in a second, Here’s is an example of poorly designed database table its lists several students and  the courses that they’re registered in and by the way there’s a little foot note down  at the bottom forget about semesters and section numbers and things like that so we’ve got people who are registered for classes what I’d like for you to do is pause this video now take out a sheet of paper and make a list of all the inconsistencies I the data redundancy that you see in this table. I noticed that Alice has three different phone numbers what’s up with this there’s inconsistencies for Ned he’s got two different last name Sanders or Sanderson the same thing is true with his student ID which of these student ID is the correct one for Ned. I don’t know if you noticed up in the column called course number we’ve got two K300 column on that meet eight o’clock and one meets at nine o’clock that’s very inconsistent which is the correct class time here for redundant data Alice is registered in three classes and her last name Is listed three times her first name is listed three times same thing with their phone number likewise for Ned we’ve got data that’s listed over and over and over and repeated in several records.
Will this all result in anomalies or problems as I said before one anomaly is an update normally.
What if Alice had a sex-exchange operation and changed your name to albert we’d have to get in all three records and three different records and change her first name, the insert anomaly.
What if we need to add a new student before the student had registered for any classes well we couldn’t add students because there would be no related data in the course number in the day and the time column that we could enter the third kind of anomaly is the delete anomaly what if we deleted $400 then we would lose poor Arie more since he was the only person that was enrolled in this course.

2 I have experienced a portion of the issues while on work. At whatever point we as a designer are given a take dependent on any current code and need to dependably confront numerous difficulties. A standout amongst the most difficult undertakings that I generally experience is understanding the information model of any application. At whatever point I get befuddled about the tables, sections, sees, values, work which dependably set aside long effort to bode well. When they do, I get the opportunity to see it from numerous points of view to improve and exploit any of the put away data. Because of poor standardization I had planned a database which was not deterministic. In the majority of the case we needed to create distinctive information designs. This is innate to the imaginative idea of the product building.
Be that as it may, there are some investigation methods that bodes well in each occurrence and to pursue the majority of the will be the most ideal approach to get the database that performs getting it done. Regardless of this, my group regularly faces databases that are planned on the fly without following the more essential job of standardization. We must be in every case clear on, each database appear, at any rate be standardized to their typical structure, since it was the format which was best spoken to towards elements and whose execution was very much adjusted among questioning and embeddings refreshing and erasing records. Related to the past issue, we needed to diminish the standardization, repetition was additionally one of the awful practices that we’ve face while taking a shot at database.