"LIKE, SELECT *, and Column Bloat"

1. What is the effect of using a leading-wildcard LIKE expression such as '%widget%'?

It performs a B-tree seek operation. It scans every row regardless of indexing. It uses a full-text search. It only matches exact string beginnings.

2. What are the potential downsides of using SELECT * in a SQL query?

It guarantees covering indexes are always used. It can increase network transfer and client memory usage. It enhances query performance by returning all columns. It prevents changes to the schema.

3. Which of the following alternatives can improve the efficiency of a query that needs to filter on a column ending with a string, like '%abc'?

Use a leading wildcard LIKE operation Reverse the string in a computed column Use SELECT * for flexibility Avoid indexing for simplicity

4. In context of handling duplicate results in SQL queries, what would be a better approach than using SELECT DISTINCT?

Using GROUP BY on all selected columns. Implementing ORDER BY for sorting results. Utilizing EXISTS to avoid duplication from joins. Using SELECT * to capture all data.

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