Considerations
Listed below are some points to consider while working with Virtual Schemas:
•	Virtual Schema DSL can be executed using 
for create/alter/delete - http://localhost:9400/rest/ execute/v1/actions/dsl/invoke 
for read - http://localhost:9400/rest/execute/v1/actions/query/invoke 
•	For annotation QUOTED_STRING, an explicit NULL keyword or a quoted string 'NULL' can be specified. This is to allow annotation to be unset or set to null explicitly.
•	Altering a virtual schema can alter the annotation or rename/relocate the virtual schema.