TDV truncates values to the right of the decimal point when converting a NUMERIC, DECIMAL, FLOAT, or DOUBLE to an INTEGER type. Some data sources do rounding; others match TDV behavior. The SQL standard leaves implementation up to the vendor.

Because of this difference, results can differ when:

In most cases, the TDV query engine warns the user when it detects a mismatch of this kind. However, the query engine cannot detect all such mismatches, and the query engine cannot normalize data source behavior for federated queries.