What are the advantages and disadvantages of indexed structures in databases?

Indexed structures in databases speed up data search and sorting, allowing quick access to records without full table scans.

Advantages:

• Fast access to data on indexed fields.
• Improved performance of SELECT queries.
• Ability to enforce uniqueness and other constraints.

Disadvantages:

• Additional memory and disk space consumption.
• Slowing down insert, update, and delete operations due to the need to update indexes.
• Complexity in choosing the right indexes for optimization.

Thus, indexes are a compromise between read speed and update costs.