Does Semantic tools like Anzo create a copy of data?

Question

I'm new to semantic technologies. I understand what RDF, OWL and Ontologies and other basic terminologies are and how semantic search uses them. When we create a semantic search module using anzo with enterprise search capabilities. It connects with various data sources and creates relationship between them. Now I'm interested in knowing what a semantic tool like anzo does internally.

1. Does it creates a copy of data on local machine or it hits data sources every time we execute a SPARQL query
2. If it stores data, is this data stored in its row format or data is stored after cleaning and creating semantic relation between them.
3. What happens to data after query is executed. How does it get current data every time?

Any thoughts over it would be valuable for me.

Thanks a lot in advance!

Answer 1

Based on your comments, it appears you're using Anzo Graph Query Engine? If so, then the answers to you questions are

1. A copy of the data is held in memory
2. Not clear from any of the published information.
3. It doesn't. You need to load in the data using the 'LOAD' command.

A bit more on 3: You would be responsible for implementing a mechanism to keep the data in here up-to-date with the underlying data source. (which might be as simple as rebuilding the graph from a nightly dump or trying to implement a change data capture against the underlying store which replicated CRUD operations on the graph)

My answers are based on the marketing and support information available on the CambridgeSemantics site.