Intermediate
Web & Software Development
Q72 / 100
What is the purpose of database indexing, and what is its main tradeoff?
Correct! Well done.
Incorrect.
The correct answer is C) Indexes speed up read queries that filter or sort on indexed columns by avoiding full table scans, but they add storage overhead and slow down writes because each index must be updated on insert/update/delete
C
Correct Answer
Indexes speed up read queries that filter or sort on indexed columns by avoiding full table scans, but they add storage overhead and slow down writes because each index must be updated on insert/update/delete
Explanation
A database index is a data structure (commonly a B-tree) that lets the engine locate rows quickly without scanning every row. The cost is extra disk space and slower writes, since every indexed column must be kept in sync whenever a row changes.
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72/100