In relation to Index structures for files which of the following are true? A. An index is an integral part of the data file. B. An index can be created in conjunction with virtually any primary record organization. C. An index cannot be created dynamically. D. An index can be used to enforce a key constraint on an attribute. E. An index can be created dynamically. Choose the correct answer from the options given below:
Index Structures File Properties Explained
This solution examines the validity of statements concerning index structures used in file management.
Statement Evaluation
- Statement A: An index is an integral part of the data file.
False. An index is typically a separate data structure that holds pointers to records in the primary data file. It is auxiliary, not integral. - Statement B: An index can be created in conjunction with virtually any primary record organization.
True. Indexes are versatile and can be implemented alongside various file organization techniques like sequential, hashed, or indexed sequential organizations. - Statement C: An index cannot be created dynamically.
False. Most modern database systems allow indexes to be created, modified, and dropped dynamically after the initial file structure is in place. - Statement D: An index can be used to enforce a key constraint on an attribute.
True. For instance, a unique index ensures that all values in the specified attribute are unique, enforcing a key constraint. - Statement E: An index can be created dynamically.
True. This statement is correct and directly contradicts statement C. Dynamic index creation is a common feature.
Final Conclusion
Statements B, D, and E are identified as true characteristics of file index structures.
Important Questions from Indexing
- In a relational database, a B+ Tree Index is to be constructed for a relation on a key field. In a B+ Tree, a Node Pointer points to a sub-tree and a Data Record Pointer points to a block of database records.
Let, Node size = 4096 bytes, Node Pointer size = 10 bytes, Search Key Field size = 11 bytes and Data Record Pointer size = 12 bytes.
The maximum number of Node Pointers that can be present in a non-leaf node of the B+ Tree is ________ . (Answer in integer) Consider a B+ Tree where the maximum number of key values in each leaf node is 2 and the maximum number of pointers in each non-leaf node is 3. Let the content of the B+ Tree be as shown in the figure.
Which of the following options denotes the key value(s) stored in the root node after inserting a key value 3 in the given B+ Tree?
An OTT company is maintaining a large disk-based relational database of different movies with the following schema:
Movie(ID, CustomerRating)
Genre(ID, Name)
Movie_Genre(MovieID, GenreID)
Consider the following SQL query on the relation database above:
SELECT *
FROM Movie, Genre, Movie_Genre
WHERE
Movie.CustomerRating > 3.4 AND
Genre.Name = “Comedy” AND
Movie_Genre.MovieID = Movie.ID AND
Movie_Genre.GenreID = Genre.ID;
This SQL query can be sped up using which of the following indexing options?
Primary index in sequential order file organisation is also known as ______.
The total cost of retrieving records in sorted order using an unclustered B+ tree is
(P-Average number of records per data page
N-Data pages
F-Ratio of the size of a data entry to the size of a data record)
