18. The system of claim 17 , wherein the database management system includes at least five of the first, second, third, fourth, fifth, and six properties, wherein evaluating the database workload comprises: determining a plurality of join predicates in the database workload; determining a set of grouping and ordering operations in the database workload; and identifying a set of tables and columns, including tables and columns used in the join predicates and tables and columns used in the set of grouping and ordering operations; wherein the statistical view advisor component is configured to compute a respective arity for each join by determining whether unique keys exist on join columns of at least one join table, wherein the query optimizer component is configured to ignore joins having one-to-one arity when generating one or more statistical views based on the refined statistical view candidates, because the joins do not improve accuracy of the query optimizer component in estimating plan costs, wherein one-to-one arity comprises having a one-to-one relationship between corresponding values contained in joined tables.
18. The system of claim 17 , wherein the database management system includes at least five of the first, second, third, fourth, fifth, and six properties, wherein evaluating the database workload comprises: determining a plurality of join predicates in the database workload; determining a set of grouping and ordering operations in the database workload; and identifying a set of tables and columns, including tables and columns used in the join predicates and tables and columns used in the set of grouping and ordering operations; wherein the statistical view advisor component is configured to compute a respective arity for each join by determining whether unique keys exist on join columns of at least one join table, wherein the query optimizer component is configured to ignore joins having one-to-one arity when generating one or more statistical views based on the refined statistical view candidates, because the joins do not improve accuracy of the query optimizer component in estimating plan costs, wherein one-to-one arity comprises having a one-to-one relationship between corresponding values contained in joined tables. 19. The system of claim 18 , wherein each skew and the predefined threshold skew are determined based on a ratio between a count of rows of a respective value having a highest frequency in a respective foreign key compared to an average count of rows per value of the respective foreign key; wherein the query optimizer component, when estimating a cardinality for a given join, treats the given join as exhibiting a plurality of predefined properties including a uniform property and an independence property, wherein the uniform property is characterized by having a same number of rows per join column table, wherein the independence property is characterized by join predicates being independent from one another; wherein the database management system includes all six of the first, second, third, fourth, fifth, and six properties, wherein the database management system supports a predefined query language, wherein the predefined query language is a declarative language and is not an imperative language, wherein the workload comprises a plurality of distinct queries composed according to the predefined query language.