A view is a type of table defined by an MI SQL query. This is not the same as a view that exists for the lifetime of a request. A view table can be a subset of a single table or multiple tables can be joined to create a view table. View tables support all the geometry data types that Spectrum Spatial supports: point, linestring, polygon, multipoint, multilinestirng, multipolygon, and collections.
A view table is always read-only. Insert and Update, therefore are not supported.
MI SQL Optimizations
Query execution attempts to combine two queries into one with the goal of alleviating performance, memory, and scalability problems. This improves the chances that the entire query (the one that defines the view) and the query on that view can be pushed entirely to the data source.
Two queries cannot be combined, however, if:
- the inner query contains a LIMIT
- the inner query contains an OFFSET
- the inner query is an aggregate
Keep these restrictions in mind when constructing a Named View Table or using a View via the Feature or Mapping Service.
For more information see the appendix Query Delegation to Data Source Providers.
XY Table Support
A view data source provider supports XY tables as a read-only data source.