SQLGetData can be used for fetching data without binding columns.
This can sometimes have a negative impact on performance because
applications have to issue a
SQLGetData ODBC call for every column of
every row that is fetched. In contrast, using bound columns requires only one ODBC call
for each fetched column. Further, the TimesTen ODBC driver is more highly optimized for
the bound columns method of fetching data.
SQLGetData can be very useful, though, for doing piecewise fetches
of data from long character or binary columns. (This is discussed for LOBs in Using the LOB Piecewise Data Interface in ODBC.)