# Question 15 Following Statements Incorrect B Tree Indexes 1 Using B Tree Index One Availab Q29138844 QUESTION 15 Which of the following statements is incorrect about B+ tree indexes? 1. Using a B+ tree index [if there is one available to use) to answer a range query cannot be slower than not using the index but just doing a table scan Aree index has some overhead to insert/update/delete statements, sometimes so large that it may not be worthwhile to create the index in the first place. It is possible to use two B+ tree indexes together to answer a single SQL query. one should decide what indexes to build based on the information of what queries will be asked by the C c users. 5 points QUESTION 16 Which of the following statements is correct? C If we have a many-to-one relationship set R connecting two entity sets E1 and E2 in an E-R diagram, we 1. may simply convert R. E1, and E2 into two relations. A weak entity set in E-R diagrams must have an attribute in it to uniquely identify each entity. When converting a many-to-many relationship set in an E-R diagram to a relation, it should always have a foreign key. C When designing E-R diagrams, we should consider what indexes to build. Show transcribed image text QUESTION 15 Which of the following statements is incorrect about B+ tree indexes? 1. Using a B+ tree index [if there is one available to use) to answer a range query cannot be slower than not using the index but just doing a table scan Aree index has some overhead to insert/update/delete statements, sometimes so large that it may not be worthwhile to create the index in the first place. It is possible to use two B+ tree indexes together to answer a single SQL query. one should decide what indexes to build based on the information of what queries will be asked by the C c users. 5 points QUESTION 16 Which of the following statements is correct? C If we have a many-to-one relationship set R connecting two entity sets E1 and E2 in an E-R diagram, we 1. may simply convert R. E1, and E2 into two relations. A weak entity set in E-R diagrams must have an attribute in it to uniquely identify each entity. When converting a many-to-many relationship set in an E-R diagram to a relation, it should always have a foreign key. C When designing E-R diagrams, we should consider what indexes to build.

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