It is a DATA BASE MANAGEMENT COURSE, NEED sql Functions!

3 Exercise 3 [10 points] For statistical analysis, a web site aggregates the number of visits in a table that was created as follows: 1 create table webstats (interval start timestamp not null, interval unit char (1) not null, page varchar (255) not null, hits int not null, primary key (interval start , interval unit, hits )); where interval_unit is H for an hour and D for a day; page of the site that was requested; and hits counts how many times the page was requested between interval_start and interval_start + the time corresponding to interval_unit. We want to keep detailed information (aggregates by hour) for recent visits, and less detailed information (aggregates by day) for visits older than three months. Write a procedure (which will be run weekly) to aggregate by day data older than three months and purge the details by hour for that data