Single Table Aggregates:
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a) They can only have a single table.
b) The SELECT list must contain all GROUP BY columns.
c) Expressions are allowed in the GROUP BY and SELECT
clauses provided they are the same.
d) They cannot have a WHERE clause.
e) They cannot have a MIN or MAX function.
f) A materialized view log must exist on the table and must 
contain all columns referenced in the materialized view. 
The log must have been created with the INCLUDING NEW VALUES clause.
g) If AVG(expr) or SUM(expr) is specified, you must have COUNT(expr).
h) If VARIANCE(expr) or STDDEV(expr) is specified,
you must have COUNT(expr) and SUM(expr).