SQL Indexes and Performance

What constitutes an index in SQL and what advantages does it provide?

Asked in the first round stage. Answer using the table below as the reference point for your explanation.

Output

1. Return one row with two columns: concept and advantages.
2. concept should briefly define what an index is in SQL.
3. advantages should summarize the main performance and access benefits.
4. Ignore any rows where the definition would be NULL.

Output details

• Use Index as the exact concept value.
• Use A database structure that speeds up lookups and can improve filtering, joins, and ordering, at the cost of extra storage and slower writes. as the exact advantages value.