Statement Options Set in SQLSetStmtAttr() - ODBC Driver for Teradata

SQL_MAX_ROWS confines the results returned to a user-specified limit. This is implemented on a per SELECT statement basis and as such, might not reduce the network traffic for multi-statement requests due to the Teradata mechanism used for spool control.

In multi-statement requests, network traffic cannot be avoided since the current result set must be scrolled through to get to the next.

In single-statement requests or if within the last statement of a multi-statement request, canceling the request reduces network traffic.

Reduce network traffic by fetching only the needed result rows of data. If all of the results from a single-statement request or from the last statement of a multi-statement request are not needed, calling SQLFreeSTMT(SQL_CLOSE) discards all pending results.

The implementation of SQL_NOSCAN varies slightly from the ODBC definition. By default, requests are scanned (parsed) to convert ODBC SQL syntax to Teradata SQL syntax.

If an application calls SQLSetStmtOption(hstmt, SQL_NOSCAN, SQL_NOSCAN_ON), ODBC Driver for Teradata does not parse SQL requests. The ODBC SDK mentions that only ODBC escape clauses are not scanned when SQL_NOSCAN_ON is set.

For custom ODBC applications that generate only Teradata-specific SQL, set SQL_NOSCAN_ON to avoid parsing SQL requests and to improve performance.