Simple Data Complex Data Query 2. Relational DBMS 4. Object-Relational DBMS No Query 1. File System 3. Persistent Language

Persistent language is a language where created objects and variables continue to exist and retain their values between runs of the program.

CREATE TABLE  employee (
  name       VARCHAR(30),
  space      polygon,
  adjacency  SET-OF( employee ) );

CREATE TABLE  floors (
  number  INTEGER,
  asf     swiss_cheese_polygon );

• For floors table records the floor number and the amount of assignable square feet (asf).


• The program reads all employee records to ascertain current spaces for employees, and it gets the asf of each floor.

  The compaction routine generates a revised allocation of employees into the asf of each floor. When compaction is complete, each employee record must be written with a new space allocation.

  main( ) { read all employees; read all floors; compact( ); write all employees; }