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Flashcards

Info Retrieval Mid Term

Joshua Arteaga Inglês 200 flashcards 2.068 visualizações

Flashcards do conjunto (200)

  1. 1Redundancy wastes space because you are storing different types of data in the same place.False
  2. 2When you need to change data, redundancy makes your changes more cumbersome and time-consuming.True
  3. 3An entity is also defined as an attribute.Flase
    An entity is a person, place, object, event, or idea for which you want to store and process data.
    Each entity has its own table.
    The attributes of an entity become the columns in the table. An attribute is a characteristic or property of an entity.
  4. 4An attribute is a characteristic or property of an entity.True
    Attributes describe and provide details about entities
  5. 5An attribute is known as a row in most databases.False.
    Rows are commonly known as records, which provide all information about the entity.
  6. 6A database will not only hold information about multiple types of entities, but also information about the relationships among these multiple entities.True,
    which is why there is a difference between relational and non-relational database
  7. 7Each table in a database represents two or more entities.False
    Each entity has its own table.
  8. 8The relationship between different entities (in different tables) is handled by their common columns.True.
    This is why keys become important in defining relationships between tables
  9. 9Software packages, called database management systems, can do the job of manipulating databases for you.True.
  10. 10Programs created with Visual Basic, Java, Perl, PHP, or C++ can access the database directly, rather than having to access it through the DBMS.False
    Many advanced text editors and IDEs have plug-ins that allow developers to access database.
  11. 11To create forms to use with a database you must write a program.Flase
    There must be a way for user to interact with the DBMS. This can done using languages like: Java, Python, JavaScript, and PHP.
  12. 12Sharing data is one advantage of database processing.True
    - Data sharing leads to larger pools of data that can be collected and maintained.
  13. 13An advantage of using the database approach to processing is that it facilitates Consistency.True
    The database approach to processing offers nine clear advantages (PG 13)
  14. 14A DBA can assign passwords to prevent unauthorized users from accessing the data.True
    A DBA can manage users and create policies
  15. 15There is a greater impact of failure in a nondatabase, file-oriented system.False //Page 16
    In a nondatabase, file-oriented system, each user has a completely separate system; the failure of any single user’s system does not necessarily affect any other user. On the other hand, if several users are sharing the same database, a failure for any one user that damages the database in some way might affect all the other users.
  16. 16Storing the same data in more than one place is called ____.Redundancy
  17. 17A(n) ____ is also called a field or column in many database systems.Attribute
  18. 18. A(n) ____ is a person, place, object, event, or idea for which you want to store and process data.Entity
  19. 19A(n) ____ is the computer counterpart to an ordinary paper file you might keep in a file cabinet or an accounting ledger.Record
  20. 20The ____ of an entity become the columns in the database table.Attribute
  21. 21Unlike a typical data file, a database can store information about multiple ____.Entities
  22. 22A visual way to represent a database is with a(n) ____.View
  23. 23Popular ____ include Access, Oracle, DB2, MySQL, and SQL Server.Relational Databases
  24. 24During the ____ process, a database expert determines the structure of the required database.Database Design
  25. 25____ are screen objects used to maintain, view, and print data from a database.Forms
  26. 26. An integrity constraint is a rule that ____.data must follow in the database
  27. 27A database has ____ if the data in it satisfies all established integrity constraints.Integrity
  28. 28____ is the prevention of unauthorized access to the database.Security
  29. 29A(n) ____ frees programmers who write database access programs from having to engage in mundane data manipulation activities, such as adding new data and deleting existing data.DBMS
  30. 30A person who is in charge of a database within an organization is often called the database ___Database Admin
  31. 31A good ____ should provide an opportunity for users to incorporate integrity constraints when they design the database.DBA
  32. 32A DBMS lets you assign users to ____.DBMS lets you assign users to groups
  33. 33____ is a property that lets you change the structure of the database without requiring you to change the programs that access the database.Data Independence
  34. 34One disadvantage of a database system isLarger file size
    Increased complexity
    Greater impact of failure
    More difficult recovery
  35. 35In a(n) ____________________ relationship between two entities, each occurrence of the first entity is related to many occurrences of the second entity and each occurrence of the second entity is related to only one occurrence of the first entity.One to many
  36. 36A program, or collection of programs, through which users interact with a database is known as a(n) _DBMS
  37. 37In an E-R diagram, ____________________ represent entities.rectangles represent entities
  38. 38In an E-R diagram, ____________________ represent relationships between connected entities.Line
  39. 39In an E-R diagram, the ____________________ at the end of a line indicates the “many” part of the one-to-many relationship between two entities.Line with a dot at the end
  40. 40A group of people in charge of a database within an organization is often called the ____________________.DBAs
  41. 41The problem of inconsistency in data is a direct result ofredundancy and not providing integrity constraints
  42. 42Eliminating ____________________ not only saves space but also makes the process of updating data much simpler.redundancy
  43. 43A good _________________________ has many features that allow users to gain access to data in a database without having to do any programming.DBMS
  44. 44A database file requires a large amount of disk space and internal __________memory
  45. 45A relational database handles entities, attributes, and relationships by storing each entity in its own table.True
    Each entity is stored in its own table. (PG31)
  46. 46The attributes of an entity become the fields or columns in a tableTrue
    The attributes of an entity become the fields or columns in the table
  47. 47Each column in a table should have a unique name, and entries in each column should all “match” this column name.True
    Each column in a table should have a unique name, and all entries in each column should be consistent with this column name
  48. 48In a relation, the order of the columns is important.The order in which columns and rows appear in a table should be immaterial.
  49. 49In a relation, the order of rows is important.In addition, each row should be unique. After all, when two rows in a table contain identical data, the second row does not provide any information that you do not already have. In addition, for maximum flexibility, the order in which columns and rows appear in a table should be immaterial (unimportant under the circumstances; irrelevant.).
  50. 50A relational database is a collection of relations.True
  51. 51An unnormalized relation is a table that has more than one row.False
    some of the entries contain repeating groups and, thus, are not single-valued. Such a structure is called an unnormalized relation.
  52. 52A column whose value uniquely identifies a given row in the table is the secondary key.False,
    that would be the primary key
  53. 53A query is a question represented in a way that the DBMS can recognize and process.True
  54. 54QBE is a visual approach to writing queries.true
    Query-By-Example (QBE)
    An approach to writing queries that is very visual. With QBE, users ask their questions by entering column names and other criteria using an on-screen grid, and data appears on the screen in tabular form. (PG33)
  55. 55Access automatically adds double quotation marks around values in the design grid that are formatted as Short Text fields when you run the query or move the insertion point to another cell in the design grid.true
    Access automatically adds double quotation marks around the value when you run the query or move the insertion point to another box in the design grid. (PG 37)
  56. 56The comparison operators are +, *, %, and /.False
    <, >, =, !=
  57. 57The comparison operators are also known as relational operators.true
    comparison operator, also called a relational operator (PG 37)
  58. 58In an AND criterion, the overall criterion is true if either of the individual criteria is true.False
    T&T = T, T&F=F, F&T=F, F&F=F
  59. 59The concept of grouping means that statistics will be calculated for individual records.True,
    functions in combination with grouping, where calculations affect groups of records.
    Grouping simply means creating groups of records that share some common characteristic.
  60. 60A relation is a(n) ____.Association between entities
  61. 61Based on the statement below, which of the following is the primary key? Rep (RepNum, LastName, FirstName, Street, City, State, PostalCode Commission, Rate)RepNum, it is the first listed attribute
  62. 62When duplicate column names exist in a database and you need to indicate the column to which you are referring,Ture, which is called qualifying the field
  63. 63Rows are also calledRecords
    (Death Row Records)
  64. 64The ____ key of a table is the column or collection of columns that uniquely identifies a given row in that table.Primary Key
  65. 65The compound criteria (conditions) are created by using ____.AND, OR
  66. 66Count, Sum, Avg, Max, and Min are a few of the built-in statistics or ____ functions that can be used in a query.Aggregate Function
  67. 67If you are sorting records by more than one field, the more important field is called the ____.Major sort key
    The other is the minor sort key
  68. 68A query that changes data is a(n) ____ query.UPDATE
  69. 69A ____ query creates a new table using the query results.CREATE TABLE
  70. 70SQL uses commands to create tables, update tables, and retrieve data from tables.True
  71. 71You can use the SQL CREATE TABLE command to insert rows into a table.False
    You use INSERT statement
  72. 72A valid name for a table might be tbl$Student.False
    Some common restrictions placed on table and column names by DBMSs are as follows
  73. 73CHAR data types are numbers without a decimal part.False
  74. 74Fields will appear in the query results in the order in which they are listed in the SELECT clause.True
  75. 75In a SELECT statement, the WHERE clause is mandatory.False
  76. 76Instead of listing all the field names in the SELECT clause, you can use the @ symbol.False
  77. 77A simple condition includes the field name, a comparison operator, and either another field name or a value.True
  78. 78There are two versions of the “not equal to” operator: <> and !=.True
    Notice that there are two versions of the “not equal to” operator: < > and !¼.
  79. 79When you connect simple conditions using the AND operator, all the simple conditions must be false for the compound condition to be true.False
  80. 80Preceding a condition by the NOT operator reverses the truth or falsity of the original condition.True
  81. 81The BETWEEN operator is an essential feature of SQL.False
  82. 82You can combine values in character fields.True
  83. 83The IN operator provides a concise way of phrasing certain conditions.True
  84. 84There is no difference between the COUNT function and the SUM function.False
  85. 85You can use the GROUP BY clause and the ORDER BY clause in the same SELECT Statement.True
  86. 86The HAVING clause is to groups what the WHERE clause is to rows.True
  87. 87When rows are grouped, one line of output is produced for each group.True
  88. 88A WHERE and a HAVING clause cannot be included in the same query.False
  89. 89For each pair of tables to be joined, a condition must be included indicating how the tables are related.True
  90. 90When you use a name containing a space in Access SQL, you must ____.enclose it in square brackets
  91. 91Many versions of SQL require you to end a command with a ____.Semicolon
  92. 92The basic form of an SQL retrieval command is ____.SELECT-FROM-WHERE
  93. 93When used after the word SELECT, the ____ symbol indicates that you want to include all fields in the query results in the order in which you described them to the DBMS when you created the table.*
  94. 94To use a wildcard, include the ____ operator in the WHERE clause.Like
  95. 95. In versions of SQL other than Access, the ____ is used as a wildcard to represent any collection of characters.percent sign ( % )
  96. 96In Access SQL, the ____ is used as a wildcard to represent any individual character.question mark (?)
  97. 97The ____ function calculates the number of entries in a table.Count
  98. 98when a subquery is used, ____ is(are) evaluated first.the subquery query
  99. 99The ____ clause can be used to create groups of records.Group By
  100. 100When rows are grouped, ____.one line of output is produced for each group
  101. 101To make changes to existing data in a table, you would use the ____ command.Update
  102. 102To add new data to a table, use the ____ command.Insert
  103. 103You can save the results of a query as a table by including the ____ clause in the Query.INTO
  104. 104Based on the code above, list the number, name, credit limit, and balance for all customers with credit limits that exceed their balances.SELECT CustomerNum, CustomerName, CreditLimit, Balance
    FROM Customer
    WHERE CreditLimit>Balance ;
  105. 105Based on the code above, list the number, name, and balance of all customers with balances greater than or equal to $2,000 and less than or equal to $5,000.SELECT CustomerNum, CustomerName, Balance
    FROM Customer
    WHERE Balance BETWEEN 2000 AND 5000 ;
  106. 106Based on the code above, list the number, name, and available credit for all customers with credit limits that exceed their balances.SELECT CustomerNum, CustomerName, CreditLimit-Balance
    AS AvailableCredit
    FROM Customer
    WHERE CreditLimit>Balance ;
  107. 107Based on the code above, list the number, name, and complete address of every customer located on a street that contains the letters “Oxford”.SELECT CustomerNum, CustomerName, Street, City, State, PostalCode
    FROM Customer
    WHERE Street LIKE "%Oxford%" ;
  108. 108Based on the code above, list the number, name, street, and credit limit of all customers. Order the customers by name within descending credit limit.SELECT CustomerNum, CustomerName, Street, CreditLimit
    FROM Customer
    ORDER BY CreditLimit
    DESC, CustomerName ;
  109. 109Based on the code above, for each sales rep, list the rep number, the number of customers assigned to the rep, and the average balance of the rep’s customers. Group the records by rep number and order the records by rep number.SELECT RepNum, COUNT(*), AVG(Balance)
    FROM Customer
    GROUP BY RepNum
    ORDER BY RepNum ;
  110. 110Based on the code above, list the number and name of all customers that are either represented by sales rep 30 or that currently have orders on file, or both.SELECT CustomerNum, CustomerName,
    FROM Customer
    WHERE RepNum='30'
    UNION
    SELECT Customer.CustomerNum, CustomerName,
    FROM Customer, Orders
    WHERE Customer.CustomerNum=Orders.CustomerNum ;
  111. 111Based on the code above, list the descriptions of all items that are located in Storehouse3 and for which there are more than 20 units on hand.SELECT Description
    FROM Item
    WHERE Storehouse='3' AND OnHand>20 ;
  112. 112Based on the code above, list the descriptions of all items that are located in Storehouse 3 or for which there are more than 20 units on hand, or both.SELECT Description
    FROM Item
    WHERE Storehouse='3' OR OnHand>20 ;
  113. 113Based on the code above, list the descriptions of all items that are not in Storehouse 3. Based on the code above, list the descriptions of all items that are not in StorehouseSELECT Description FROM Item WHERE NOT Storehouse='3' ;
  114. 114Based on the code above, find how many items are in category TOY.SELECT COUNT(*) FROM Item WHERE Category='TOY' ;
  115. 115Based on the code above, list the complete student table.SELECT * FROM Student ;
  116. 116Based on the code above, list the name of every student whose postal code is 10113.SELECT FirstName, LastName FROM Student WHERE PostalCode='10113' ;
  117. 117Based on the code above, find the name of the student whose ID is 1167.SELECT FirstName, LastName FROM Student WHERE StudentID='1167' ;
  118. 118Based on the code above, change the postal code of the student with ID 11433 to 14455.UPDATE Student SET PostalCode='14455' WHERE StudentID='11433' ;
  119. 119Based on the code above, delete any row in the OrderLine table in which the item number is MT03.DELETE FROM OrderLine WHERE ItemNum='MT03' ;
  120. 120Views cannot be used to examine table data.False.
  121. 121An individual can use a view to create reports, charts, and other objects that show database data.True.
  122. 122A view is a physical table in the DBMS.False
  123. 123To create a view in Access, you simply create and then save a query.True
  124. 124One advantage of using views is that they provide data dependence.False.
  125. 125One advantage of a view is that different users can view the same data in different ways.True
  126. 126Indexes can increase the efficiency with which data is retrieved from the database.True
  127. 127When you create an index whose key has a single field, you have created what is called a single-column index.True
  128. 128The command DEL INDEX CustList; would remove the index named CustList.False.
    The SQL command used to drop (delete) an index that is no longer necessary is DROP INDEX, which consists of the words DROP INDEX followed by the name of the index to drop.
  129. 129The following command will enable Jones to retrieve data from the Customer table, but not to take any other action: GRANT SELECT ON Customer Jones ;False.
    The following command will enable user Jones to retrieve data from the Customer table but not take any other action.GRANT SELECT ON Customer TO Jones
  130. 130Referential integrity is specified using the FOREIGN KEY clause in the SELECT command.False
  131. 131Legal-values integrity is the property that states that no record can exist in the database with a value in the field other than one of the legal values.True
  132. 132Information about tables in the database is kept in the system catalog.True
  133. 133A stored procedure is placed on a client computer.False
  134. 134Access supports stored procedures.False
  135. 135The ____ command will create an application program's or individual user's picture of the database.CREATE VIEW
  136. 136A row-and-column subset ____ consists of a subset of the rows and columns in some individual table.View???
  137. 137To create an index named RepBal with the keys RepNum and Balance and with the balances listed in descending order, the command is ____.CREATE INDEX RepBal ON
    Customer (RepNum, Balance DESC) ; ???
  138. 138The ____ statement will take away user privileges to the database.REVOKE
  139. 139In Access, a key symbol appears in the row selector of the field that is the ____ key.Primary
  140. 140To create the primary key clause for the Customer table on the CustomerNum field, the correct statement is ____.PRIMARY KEY (CustomerNum)
  141. 141To create the primary key clause for the OrderLine table on the OrderNum and ItemNum fields, the correct statement is ____.PRIMARY KEY (OrderNum, ItemNum)
  142. 142Essentially, setting the value in a given field to ____ is similar to not entering a value in it at all.Null
  143. 143Which of the following statement fragments will only allow a CreditLimit of $5,000, $7,500, or $15,000?CHECK (CreditLimit IN (5000, 7500, 15000))
  144. 144The CHECK clause can be included in the ____ command.ALTER TABLE
  145. 145In SQL, you use the CHECK clause to enforce ____ integrity.Legal-values
  146. 146A table that is in first normal form is better than one that is in second normal form.False.
    4th > 3rd > 2nd > 1st
  147. 147To correct update anomalies in a database, tables must be converted into various types of normal forms.True.
  148. 148If B is functionally dependent on A, you can also say that B functionally determines A.True
  149. 149Functional dependencies can be determined by looking at sample data.False
  150. 150Removal of repeating groups is the starting point in the quest to create tables that are as free of problems as possible.True
  151. 151In general, when converting a non-first normal form table to first normal form, the primary key will usually include the original primary key concatenated with the key to the repeating group.True
  152. 152A table that is in first normal form may contain problems that will require you to restructure it.True
  153. 153If the primary key of a table contains only a single column, the table is automatically in first normal form.False
  154. 154In a dependency diagram, the arrows below the boxes indicate the normal dependencies.False
  155. 155Tables that are in second normal form do not contain problems.False
  156. 156The most recent definition of third normal form is referred to as the Boyce-Codd normal form.True
  157. 157. The primary key in a table will be a determinant.True
  158. 158Converting to third normal form always avoids the problems related to dependencies.False
  159. 159The normalization process used to convert a relation or collection of relations to an equivalent collection of third normal form tables is a crucial part of the database design process.True
  160. 160By splitting relations to achieve third normal form tables, you create the need to express interrelation constraints.True
  161. 161Potential problems in the design of a relational database are known as ____.Update anomalies.
  162. 162The fact that column B is functionally dependent on column A can be written as ____A → B.
  163. 163If B (an attribute) is functionally dependent on A, we can also say that ____.A functionally determines B.
  164. 164The ____ is a column (or collection of columns) A such that all other columns are functionally dependent on A and no subcollection of the columns in A has this property.Primary Key.
  165. 165The definition for ____ also defines a candidate key.Primary Key.
  166. 166A(n) ____ is a column or collection of columns on which all columns in the table are functionally dependent.Candidate key.
  167. 167An alternate key is a ____Column that could be a primary key but was not chosen.
  168. 168A table is in first normal form if it does not contain ____.Repeating groups.
  169. 169A table that contains a repeating group is called a(n) ____.Unnormalized relation.
  170. 170If there is more than one possible choice for the primary key, and one of the possibilities is chosen to be the primary key, the others are referred to as ____.Alternate keys.
  171. 171From all the ____ keys, one is chosen to be the primary key.Candidate.
  172. 172Which of the following contains a repeating group? ​Orders (OrderNum, OrderDate, (ItemNum, NumOrdered) ) ​Orders (OrderNum, ItemNum, NumOrdered ) ​Orders (OrderNum, OrderDate) ​Orders (OrderNum, OrderDate, ItemNum, NumOrdered )Orders (OrderNum, OrderDate, (ItemNum, NumOrdered) )
  173. 173A column is a nonkey column if it is ____.Not a part of the primary key.
  174. 174Another name for a nonkey column is a ____.Nonkey attribute.
  175. 17530. Second normal form can be defined as a table that is in first normal form but that contains no ____.Partial dependencies.
  176. 176The information-level design methodology involves representing the individual user view as a collection of tables, refining them to eliminate any problems, and then merging them into a cumulative design.True
  177. 177A design that supports all user views is called a constructive design.False
  178. 178The second step in creating a user view is to represent the user view as a collection of tables.False
  179. 179The first step in creating a user view is to normalize the tables.False
  180. 180When provided with a user view or some sort of stated requirement, you must develop a collection of tables that will support it.True
  181. 181The primary key is a unique identifier.True
  182. 182The basic relationships among entities are: one-to-many, many-to-many, and one-to one.True.
  183. 183In a one-to-many relationship, the primary key of the “many” table becomes the foreign key of the “one” table.False
  184. 184Careful planning in the early stages of the normalization process will usually avoid the need to consider fourth normal form.True
  185. 185You create a many-to-many relationship by creating a new table whose primary key is the combination of the primary keys of the original tables.True
  186. 186There are two types of primary keys that you can use in your database design.False
  187. 187A foreign key is a column or collection of columns in one table that is required to match the value of the primary key for some row in another table, or be null.True
  188. 188In DBDL, you represent a table by listing all columns and then underlining the primary key.True
  189. 189In an entity-relationship diagram, rectangles represent foreign keys.False
  190. 190When you use an E-R diagram to represent a database, it visually illustrates all the information listed in the DBDL.True
  191. 191In an E-R diagram, a dashed line represents an identifying relationship and a solid line represents a nonidentifying relationship.False.
  192. 192Nulls are used when a value is either unknown or inapplicable.True.
  193. 193When you combine third normal form tables, the result will always be in third normal form.False.
  194. 194The use of an “m” and an “n” in an E-R diagram indicates a many-to-many relationship.True
  195. 195A weak entity is a column or collection of columns that could have been chosen as a primary key, but was not.False
  196. 196A set of requirements that is necessary to support the operations of a particular database user is known as a(n) ____.User View.
  197. 197he properties of the entities you choose as you design the user view will become the ____ in the appropriate tables.Columns
  198. 198If each employee works in a single department and each department has only one employee, the relationship between employees and departments is ____.One-to-one
  199. 199A(n) ____ is a primary key that consists of a column that uniquely identifies an entity, such as a person’s Social Security number.Natural Key?
  200. 200A column that you create for an entity to serve solely as the primary key and that is visible to users is called a(n) ____.Artificial Key.

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FlashCards sobre Info Retrieval Mid Term , criado por Joshua Arteaga em 09-10-2018.
Criado por
Joshua Arteaga
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