Since I am new to the Virtuoso and Triplestore, I have a doubt that when uploading the ttl or owl file (say modified triples) to the existing DB (which has the same triples) will it override the whole data or just update the missing attribute to it?
Also, need to know how can we remove the ttl/owl file data from the Virtuoso DB.
Which of the Virtuoso RDF Data Insert Methods are you using to upload the ttl or owl files ? Generally either method will result in any existing triples being overwritten and any new triples added.
Virtuoso does have a Delta-aware bulk loading of RDF datasets method which would only load the new data (ie update rather that insert all). Which is of particular value when bulk loading large RDF datasets, although this is only supported for NQUAD dataset files as detailed in the prerequisites section of the docs.
To remove the ttl/owl file data you would need to know the names for the RDF graphs they were loaded into and use the SPARQL 1.1 drop or clear graph query operations to remove them. Noting the need to use log_enable(3) when deleting large graphs.