INTRODUCTION TO ASYCUDA++ Ó UNCTAD - SITE (V1.15) 1.10 Processing performed on server, means that client can perform other tasks locally. When  the  user  sends  data  for  processing  on  the  server  he  frees  up  his  Client  PC  processor  for further transactions that can be carried out at a local level. Ease of upgrading storage and processing capacity The   ease   with   which   Personal   Computer   storage   capacity   can   be   increased   is   well   known. Individual Client machines on the network can be isolated and upgraded without interruption to the processing of other Client PCs, which is a significant saving in terms of potential down time over the more problematic Server/Dumb terminal configuration. The ASYCUDA++ Client-Server environment Communication   between   the   client   and   server   takes   place   in   a   transparent   fashion   using ASYCUDA++ that in turn relies upon TCP/IP. The user is never aware that he is accessing remote data once he has performed the initial login to the server. As server-processing power is reserved solely for database administration, response time is in not normally delayed by any external access. The ASYCUDA++ Client Within the ASYCUDA++ framework, each user has his own PC (Client) with which he may, when necessary, log into ASYCUDA++.  The PC is loaded with the ASYCUDA++ client software and the user,   when   logged   in   to   the   server,   is   presented   with   the   ASYCUDA++   menu   screens   and functions, many of which can be used without any need to log in to the server. Operating System The advantages of the DOS/Windows â environment  have  been  elaborated  above.  Suffice  to  say that as the most popular operating system in the world its selection was self-evident. This is not to say however that DOS is necessary for the running of ASYCUDA++, it is possible to change the operating system to Windows â at a later stage if desired. PARADOX Database Management System PARADOX     is     one     of     the     better-known     database     management     tools     available     under DOS/Windows â .   In   basic   on-line   mode   it   is   extremely   user   friendly   with   its   QBE   (Query   by Example) screens, its extensive reporting facilities and the ease with which its data can be exported for use in other applications. As the development of software under the PARADOX engine carries no charges, there are none to pass on to the user countries. This consideration may be useful for those considering developing their own applications using the same environment. Borland SQL Interface The  ASYCUDA++  software  is  written  in  such  a  way  that  the  user  interface  and  local  Engine modules  refer  to  the  BORLAND  provided  SQL  interface  rather  than  embedding  SQL  statements directly in the program code.  It is this interface that interacts with the PARADOX database, and it is only  this  layer  of  the  system  that  would  need  to  be  changed  if  another  interface  replaced  the database beneath it. Local Engine To   avoid   unnecessary   access   to   the   network,   the   system   reference   or   "control"   files   are automatically  updated  on  the  Client  PCs  so  that  much  interim  validation  can  be  carried  out  at  a local level. It is only when ASYCUDA++ transaction files are to be updated that connection to the network is necessary and final validation is carried out against the master database. This means that  the  users  have  the  facility  to  create  or  capture  data  using  local  database  files  rather  than competing for time on the server. For external applications interfacing with ASYCUDA++ the down loading of reference data to the local machines is interesting. This indicates that additional applications can, if required, access and update the ASYCUDA++ databases resident in DOS/Windows â .