Week 04 Lectures (31)

SQL vs DBMS engine

select ... from R where C
- find relevant tuples (satisfying C) in file(s) of R
insert into R values(...)
- place new tuple in some page of a file of R
delete from R where C
- find relevant tuples and "remove" from file(s) of R
update R set ... where C
- find relevant tuples in file(s) of R and "change" them