Data-at-Execution and Text, ntext, or Image Columns
ODBC data-at-execution is a feature that enables applications to work with extremely large amounts of data on bound columns or parameters. When retrieving very large text, ntext, or image columns, an application may not be able to simply allocate a huge buffer, bind the column into the buffer, and fetch the row. When updating very large text, ntext, or image columns, the application might not be able to simply allocate a huge buffer, bind it to a parameter marker in an SQL statement, and then execute the statement. In these cases, the application must use SQLGetData or SQLPutData with its data-at-execution options.