...
Odysseus provides a semantically correct and (in most cases) deterministic processing of events. Although special cases may lead to a non-deterministic processing, the results of operators based on the standard relational algebra are always semantically equivalent. To achieve this, Odysseus provides a powerful meta data concept. Every event is annotated with meta data transparently.
The usage of Metadata can be defined in Odysseus Script with the #METADATA command or in the Access operator with the METAATTRIBUTE parameter.
The operators in Odysseus must not be aware which meta data they process. Therefore, special meta data merge functions are provided. They will be injected at query compile time.
...