Fundamentals of Database Systems Questions and Answers
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The document consists of a quiz related to database concepts, including entity types, attributes, and relationships. It covers basic terms and data models in database management systems, as well as the process of transforming ER diagrams into relational schemas. Additionally, it discusses challenges associated with database design and a nonprofit organization focused on improving education in technology and computer science.
Fundamentals of Database Systems Questions and Answers
- 1. https://www.facebook. com/Oxus20 Abdul Rahman Sherzad Page 1 of 5 PART I – Single and Multiple choices: 1) The common types of entities are: Strong entities Weak entities Associative entities All of the above 2) The logical representation of an organization's data is called a(n): Database model Entity-relationship model Relationship systems design Database entity diagram 3) Customers, cars, and parts are examples of: Entities Attributes Cardinals Relationships 4) An entity type whose existence depends on another entity type is called a(n) _____ entity. Strong Weak Codependent Variant 5) A(n) _____ is the relationship between a weak entity type and its owner. Member chain Jump path Chain link identifying relationship 6) A property or characteristic of an entity type that is of interest to the organization is called a(n): Attribute Coexisting entity Relationship Cross-function 7) A person's name, birthday, and social security number are all examples of: Attributes Entities Relationships Descriptors 8) An attribute that can be broken down into smaller parts is called a(n) _____ attribute. Associative Simple Composite Complex
- 2. https://www.facebook. com/Oxus20 Abdul Rahman Sherzad Page 2 of 5 9) The following figure shows an example of: A composite attribute A relational attribute A derived attribute A multivalued attribute 10) An attribute that can be calculated from related attribute values is called a(n) _____ attribute. Simple Composite Multivalued Derived 11) The total quiz points for a student for an entire semester is a(n) _____ attribute. Derived Mixed Stored Addressed 12) Which of the following criteria should be considered when selecting an identifier? Choose an identifier that is stable Choose an identifier that will not be null Choose an identifier that doesn’t have large composite attributes All of the above 13) Which of the following conditions should exist if an associative entity is to be created? All the relationships for the participating entities are many-to-many The new associative entity has independent meaning The new associative entity participates in independent relationships All of the above
- 3. https://www.facebook. com/Oxus20 Abdul Rahman Sherzad Page 3 of 5 14) The number of entity types that participate in a relationship is called the: Number identifying characteristic Degree Counter 15) A relationship between the instances of a single entity type is called a(n) _____ relationship. Ternary Primary Binary Unary Part II - Basic Terms and Data Model: 1) Persons can take the following roles around database systems: End users DB designers DB administrators Application Programmers Decide for each of the following activities, to which role it belongs by writing the respective number in the box. Developing the conceptual schema Managing user accounts, hardware resources, and backups during the lifetime of the database Programming of software that is using the database Choice of DBMS Analyze requirements for the database Programming of a graphical user interface for the database Gathering of information about the application field
- 4. https://www.facebook. com/Oxus20 Abdul Rahman Sherzad Page 4 of 5 2) Classification of Database Management Systems: a) Name three different data models that can be used in DBMS: Relational Model Object Relational Model Network Model b) Which data model is used by MySQL? Relational Model c) Is MySQL a single-user or a multi-user DBMS? Multi-User Part III – ER to Relational Mapping: 1) Name and explain in brief (just briefly), the steps that are needed to transform an ER diagram into a relational schema. 1. Mapping Strong Entities 2. Mapping Weak Entities 3. Mapping One-to-One relationship 4. Mapping One-to-Many relationship 5. Mapping Many-to-Many relationship 6. Mapping Multi-Valued attributes 7. Mapping N-ary relationship
- 5. https://www.facebook. com/Oxus20 Abdul Rahman Sherzad Page 5 of 5 Part IV – Challenges: 1) You have the following two figures. Both using the one-to-many relation but in different ways. Are they the same? Yes / No, Give reason. Using the above "One-to-Many" relationship the implementation is simple and easy; but support one depth and level of relationship, as for instance, a sub-forum can't have other sub-forums! Using the above recursive relationship it supports both one level and as many level as possible of nested relationships. For instance, a forum can have a sub-forum; the sub-forum still can have other sub-forums and yet that other sub-forums can have sub-forums and so on, so forth. 2) There is something wrong with the following query (The problem is the single quotation-marks with the string). Try to rewrite it with correct syntax using two different methods. SELECT * FROM lecturers WHERE signatory = 'If you tell the truth, you don't have to remember anything'; SELECT * FROM lecturers WHERE signatory = "If you tell the truth, you don't have to remember anything"; SELECT * FROM lecturers WHERE signatory = 'If you tell the truth, you don't have to remember anything'; Forum Sub Forum has 1 m Forum has 1 m main sub Figure 1 - One-to-Man Figure 2 - Recursive
- 6. OXUS20 is a non-profit society with the aim of changing education for the better by providing education and assistance to IT and computer science professionals. آکعی ضَ 02 یک ا جًوي غیر ا تًفاعی تا ذّف تغییر تم یَت آه زَغ پر رٍغ از طریك ارائ آه زَغ کوک ت هتخصصاى عل مَ کاهپی تَر اظت . اًم ایي ا جًوي ترگرفت از دریای آه پر آب تریي ر دٍ آظیای هیا ک دظت ه جَ آى تیا گًر اظتعذاد اّی فًْت ایي ا جًوي ت دَ ،ُ ایي دریا از داه اّی ک يْ پاهیر ظرچؽو گرفت ها رٍای ؼوالی ظرزهیي تاظتا یً افغا عًتاى را آتیاری هیک ذٌ ک ایي حالت دریا ذّف ارای خذهات ا جًوي را ا عًکاض هیذ ذّ. آکعی ضَ 02 در ظًر دارد تا خذهاتی ها ذًٌ ایجاد فضای ه اٌظة ترای تجلی اظتعذاد اّ ترا گًیختي خلالیت ؼک فَایی علوی هحصلاى دا ػً پص اٍّى، اًْده ذٌ ظاختي فعالیت اّی ف قَ تر اًه علوی کارتردی، ؼ اٌظایی افراد خلاق، خًث علالو ذٌ ت رْ گیری از هؽارکت آ اًْ در ارتمای فضای علوی پ تٌَّ ىَ اّ دیگر هراکس آه زَؼی جاهع وّچ ىَ ت لَیذ ا تًؽار ؽًریات علوی تخصصی عل مَ عصری تک اٌل شَی هعل هَاتی را ت ؼکل ه ثَر آى در جاهع در راظتای رّچ ت تْر ؼذى زهی تذریط، تحمیك پص ػٍّ را اّی رظیذى ت آهال افراد جاهع را فرا نّ هیعازد. Follow us on Facebook, https://www.facebook.com/Oxus20