To optimize the given query "select id, class from student where name='happy'", you should apply indexing on the "name" column in the "student" table. Indexing the "name" column will help speed up the search for rows that match the specified name value ('happy').
By creating an index on the "name" column, the database engine can quickly locate the rows that satisfy the WHERE clause condition without performing a full table scan. This is especially beneficial when the "student" table contains a large number of rows, as it reduces the time and resources required to retrieve the desired data.
Here's an example of how you can create an index on the "name" column in SQL:
CREATE INDEX idx_name ON student(name);
Once the index is created, the database engine will use it to efficiently retrieve the rows that match the name 'happy' when executing the given query. Keep in mind that while indexing can significantly improve query performance, it's essential to strike a balance as indexes come with their overhead, especially during data modifications (INSERT, UPDATE, DELETE). Therefore, it's crucial to consider the specific usage patterns and workload of your database when deciding on the appropriate indexes to create.
