IBCustomDataSet

TIBDSBlobStream is the type of stream returned when an application calls an IB dataset's CreateBlobStream method. Use this stream to access or modify the value of a Blob field in the dataset. TIBDSBlobStream allows objects that have no specialized knowledge of how data is stored in a Blob field to read or write such data by employing the uniform stream interface. 

To use TIBDSBlobStream, call CreateBlobStream to obtain an instance of the stream and use the methods of the stream to read or write the data. The dataset retains ownership of the stream, so you should not free this Blob stream when you are done.