What is more efficient for data retrieval — using indexed search or sequential table scanning?

Indexed search is usually much more efficient than sequential table scanning, especially with large volumes of data.

Indexed Search:

• Allows quick finding of records by key or indexed field.
• Acts as a pointer to the needed data, avoiding a full scan.
• Search complexity is usually O(log n) or better.

Sequential Scanning:

• Goes through all table rows, checking conditions.
• Complexity is O(n), which is slower with large data.

However, if the table is very small or the query returns a large part of the data, sequential scanning can be faster due to the absence of overhead from using an index.

Overall, for finding specific records or filtering by indexed fields, indexed search is preferred.