About: http://webisa.webdatacommons.org/295368624

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	After the tables and columns are selected for a second query, the selected columns are verified against the first query to make sure the number of columns and their data types match, which is required for SQL UNION operation.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com