Final answer:
A partial index is a subset of records in the main file and doesn't contain an entry for every record. This is in contrast to a primary index, which typically does include one entry for every record in the main file to ensure quick access to the data. This is false.
Step-by-step explanation:
The statement is False. A partial index is created to improve the performance of database queries by indexing a subset of the records in the main file. Unlike a full index, which contains one entry for every record in the main file, a partial index only includes entries for a specific subset of records that meet certain criteria.
For example, in a database of student records, a partial index could be created to only include entries for students who have a GPA above a certain threshold. This allows queries that involve filtering by GPA to be more efficient, as the index only needs to be searched for the relevant subset of records.
By excluding unnecessary records, partial indexes can significantly reduce the size of the index, improve query performance, and reduce the overhead of index maintenance. This is in contrast to a primary index, which typically does include one entry for every record in the main file to ensure quick access to the data.