Platform

• DBMS: Informix DS v 7, 9, 11.50
• AnyDAC: v 2.0.11.895
• Delphi: v 5

The application

The AnyDAC customer had an application, which is the ERP-system with ~2000 of units. 95% of the units are the forms and the data-modules. The applications was using BDE & Informix SQL Link. Worth to mention, it was using quite a lot of TTable's.

Migration

• The connection definition like following was used to connect to the Informix server:
  

  [Informix_Demo]
  DriverID=ODBC
  ODBCDriver=IBM INFORMIX ODBC DRIVER
  User_Name=informix
  Password=informix2
  Database=sysuser
  ODBCAdvanced=HOST=DA;SRVR=ol_svr_custom;SERV=svc_custom;
      PRO=olsoctcp;CLOC=en_US.CP1252;DLOC=en_US.819 

• 2days. The most of the work has been performed using AnyDAC dfmChanger utility. The general BDE -> AnyDAC migration process will be documented later in AnyDAC WiKi.
• Then additionally was ported internal dataset descendant components. 56kb of the changed source code.
• 7 days. Testing and replacing "non-compatible" code places.

Potential issues

• The Informix ODBC driver must be v 2.81 and higher. Otherwise you can get some unstable behaviour.
• Old Informix versions does not give the "readable" names to the stored procedure parameters. So, application cannot use ADQuery.ParamByName('(expression)') or FieldByName. The customer replaced all such calls with ADQuery.Params[] and Fields[].

The results

The application speed is the same as with BDE. It seems, that BDE SQL Link is using Informix CLI, which is very close to the ODBC API. As result:

• the same speed;
• the same stability;
• the much better support;
• and much more features.

Kind of that. Good luck in the migration to the AnyDAC ! :)