Assertion: index | /r/HasProperty | merged
Facets:
value: from a variety of sources
type: OTHER
value: easily
type: MANNER
Source sentences:
text: A grid-based spatial index has the advantage that the structure of the index can be created first, and data added on an ongoing basis without requiring any change to the index structure; indeed, if a common grid is used by disparate data collecting and indexing activities, such indices can easily be merged from a variety of sources.