| std::optional<ClearHistoryPolicy> DataStorm::Config::clearHistory |
The clear history policy specifies when the sample history is cleared.
nullopt is equivalent to the topic's default clear history policy: the value of the DataStorm.Topic.ClearHistory property (OnAll by default, which effectively disables the sample history as it then holds at most the latest sample), unless replaced with Topic::setReaderDefaultConfig or Topic::setWriterDefaultConfig.
1.17.0 