Compatibility with existing RDDs

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Compatibility with existing RDDs

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The primary target when designing the VO2ADO RDD was:


to be as much compatible as possible with the existing RDDs, especially the DBFNTX and DBFCDX RDD.


We have the feeling that we have succeeded in doing so, but the compatibility is not 100%.



The most important difference (we feel) is:


The Vo2Ado RDD (for performance reasons) does not automatically read the first row from the result set.

You must call one of the navigational commands / functions or DbServer methods such as Go Top, Go Bottom or Go to, Append or Seek to execute the SQL Query and retrieve rows from the back end.


Using the VO2ADO RDD means using VO's default workarea based data access.

That means that you can operate the RDD 4 different ways:


Using the Data Access commands

Using the DB..() functions                

Using the VODB..() functions

Using the DbServer Class


Of course there are also some differences between the existing RDDs and the Vo2Ado RDD


Connection information

Index support

Table based vs. File based


You can also inspect the properties of a Open VO2ADO Table inside the VO IDE in the Debugger as you can see below: