Overall Design

• In the UNIX style
• Each process is a program
• communicate via pipes or temporary files e.g.:

  	  unix% program1 | program2
  
  	  unix% program1 > tmp
  	  unix% program2 < tmp
  	

• Data are 7-bit ASCII text files
• Each line is a datum (single access, request, indexed field, ...)
• This allows use of standard UNIX text tools such as grep, awk, sed and perl