Known limitations of operations on Siren JDBC datasources
- Cross backend join currently supports only integer keys.
- Cross backend support has very different scalability according to the direction of the Join, a join which involves sending IDs to a remote system will be possibly hundreds of times less scalable (e.g. thousands vs millions) to one where the keys are fetched from a remote system.
- Only terms aggregations can be nested inside a parent bucket aggregation.
- The
missing
parameter in bucket aggregations is not supported. - Scripted fields are not supported.
- When issuing queries containing string comparisons, the plugin does not force a specific collation, if a table behind a virtual indices uses a case insensitive collation, string comparisons will be case insensitive.
- Wildcards on virtual index names are not supported by any API; a wildcard search will silently ignore virtual indices.
- Currently cross cluster searches on virtual indices are not supported.
The type of Cypher (Neo4j) query that can currently be used is limited. It is recommended that you use a connector script. For more information, see the Neo4J Siren preview document.
Neo4J cannot be used to create virtual indices. It can be used to perform reflection jobs only.