Changing session character set from ASCII to UTF8 causes trailing white spaces.

UDA

Changing session character set from ASCII to UTF8 causes trailing white spaces.

When I change the session character set from ASCII to UTF8 the published data has trailing white spaces.

I enabled tracing for Teradata driver(in ODBC data source administrator) and captured the traces for both cases and found that under the SQLDescribeCol for the data item, the SQLULEN is 109for ASCII) and 20 (for UTF8). Is this the cause for the trailing white spaces.

Why does the SQLULEN double in the case of UTF8.

Thanks,
Sujata