| RDS 2.5 API Reference |  |
| RDS 2.5 API Reference | |
Indicates the type of asynchronous fetching.
Sets or returns one of the following values.
| Constant | Description |
|---|---|
| adcFetchUpFront | All the records of the Recordset are fetched before control is returned to the application. The complete Recordset is fetched before the application is allowed to do anything with it. |
| adcFetchBackground | Control can return to the application as soon as the first batch of records has been fetched. A subsequent read of the Recordset that attempts to access a record not fetched in the first batch will be delayed until the sought record is actually fetched, at which time control returns to the application. |
| adcFetchAsync | Default. Control returns immediately to the application while records are fetched in the background. If the application attempts to read a record that hasn't yet been fetched, the record closest to the sought record will be read and control will return immediately, indicating that the current end of the Recordset has been reached. For example, a call to MoveLast will move the current record position to the last record actually fetched, even though more records will continue to populate the Recordset. |
Note Each client-side executable file that uses these constants must provide declarations for them. You can cut and paste the constant declarations you want from the file Adcvbs.inc, located in the C:\Program Files\Common Files\System\MSADC folder.
In a Web application, you will usually want to use adcFetchAsync (the default value), because it provides better performance. In a compiled client application, you will usually want to use adcFetchBackground.
Applies To: DataControl Object (RDS)