CHAR, VARCHAR, and RAW data types

If you attempt to obtain the CHAR, VARCHAR, or RAW column as a data stream without redefining the column type, the JDBC driver returns Java InputStream without actually transmitting the stream.

For these data types, the JDBC driver extracts all data into the memory buffer when calling the executeQuery or next method. The streams that read data from the buffer are returned at the entrypoint of the getXXXStream method.