Override Protections

When copying data using HEC-RTS, either through the Extract or Post functions, it's important to understand how override protections work.

The available options depend on the destination of the data: an HEC-DSS file or an Oracle (CWMS) database.

Destination: HEC-DSS

When writing to an HEC-DSS file (e.g., forecast.dss or a shared HEC-DSS file), you can choose from the following options based on the type of time series data:

Regular Time Series

Option	Description
Replace All	Replaces all existing values with incoming data. Does not create or delete records of missing data.
Replace Missing Values Only	Only fills in missing values in the file with incoming data.
Replace and Create	Replaces all values and creates entire records of missing data if needed.
Replace and Delete	Replaces all values and deletes any records that are entirely missing.
Replace with Non-Missing	Replaces all values, but does not overwrite existing non-missing values with incoming missing ones.

Irregular Time Series

Options	Description
Replace	Deletes all existing values within the incoming time window, then stores the new data.
Merge	Inserts new values and replaces existing ones—even if incoming values are missing.

Destination: Oracle (CWMS Database, CDA)

When posting to an Oracle database (e.g., CWMS Database, CDA), these override options apply to both regular and irregular time series:

Options	Description
Delete Insert	Deletes all existing values in the incoming time window, then inserts new data.
Replace All	Inserts at new times and replaces any values at existing times—even if incoming values are missing.
Do Not Replace	Inserts at new times only; existing values are never overwritten.
Replace Missing Values Only	Replaces existing values only if they are missing. Inserts at new times as usual.
Replace with Non-Missing	Replaces existing values unless the incoming value is missing. Inserts at new times as usual.

Choose your override option carefully based on the data integrity requirements of your workflow. For example, Replace Missing Values Only is a safe choice when preserving existing validated data.