Podcast
Questions and Answers
What happens when an entry for the search key exists in a sparse index?
What happens when an entry for the search key exists in a sparse index?
- The entry is left unchanged.
- The entry is replaced with the previous search-key value in the file.
- The entry is deleted by replacing it with the next search-key value in the file. (correct)
- The entry is inserted into the index.
In a dense index, what happens when the search-key value does not appear in the index?
In a dense index, what happens when the search-key value does not appear in the index?
- The search-key value is deleted from the index.
- The search-key value is inserted into the index. (correct)
- The index is reorganized.
- The index is left unchanged.
What is the purpose of a hash function in file organization?
What is the purpose of a hash function in file organization?
- To sort the records in a file.
- To optimize query performance.
- To reorganize the index periodically.
- To obtain the bucket of a record directly from its search-key value. (correct)
What problem arises when the number of buckets (B) is small in a hash file structure?
What problem arises when the number of buckets (B) is small in a hash file structure?
What is the purpose of periodic re-organization of the file with a new hash function?
What is the purpose of periodic re-organization of the file with a new hash function?
What is the benefit of dynamically modified hash functions?
What is the benefit of dynamically modified hash functions?
What is the primary purpose of an index structure in a database?
What is the primary purpose of an index structure in a database?
What is the term for the attribute or set of attributes used to look up records in a file?
What is the term for the attribute or set of attributes used to look up records in a file?
What type of search is supported efficiently by certain indexing techniques?
What type of search is supported efficiently by certain indexing techniques?
What is the term for the time taken to find a particular data item or set of items?
What is the term for the time taken to find a particular data item or set of items?
What is the purpose of a primary index in a file?
What is the purpose of a primary index in a file?
What search technique is used to search through the indices of the index file?
What search technique is used to search through the indices of the index file?
What is the primary reason why a nested-loop join is considered expensive?
What is the primary reason why a nested-loop join is considered expensive?
What happens when at least one relation fits into memory?
What happens when at least one relation fits into memory?
What is the primary function of an index in a database?
What is the primary function of an index in a database?
What is the key difference between an ordered index and a hash index?
What is the key difference between an ordered index and a hash index?
What is the purpose of a search key in an index?
What is the purpose of a search key in an index?
What is the benefit of using an index in a database?
What is the benefit of using an index in a database?
