FetchUnit details

The unit of data is adapter-specific.

• If the adapter is File, the FetchUnit refers to a logical unit of data and divides map execution into valid units of work based on a logical unit of data.

For other adapters, the FetchUnit refers to a physical unit of data.

• For messaging adapters, the FetchUnit setting determines the number of messages per burst.
• For database adapters, the FetchUnit setting determines the number of database rows.

When an input FetchAs = Integral, the Source is requested to retrieve data once for the entire mapping.

When an input FetchAs = Burst, the data is retrieved once per burst.

For example, a database has the rows sorted in reverse chronological order by date. You want to map only the first row because that row contains the most recent data. Set the input FetchAs = Integral and FetchUnit = 1. Only the first row in the database is accessed.

Using different FetchUnit values for the same data object on multiple input cards has limitations.