Oracle Error ORA-30452: cannot compute AVG(X), VARIANCE(X) or STDDEV(X), without COUNT(X) or SUM(X)

Oracle Error Message

ORA-30452: cannot compute AVG(X), VARIANCE(X) or STDDEV(X), without COUNT(X) or SUM(X)

Reason for the Error

Incremental refresh of summaries requires a COUNT(X) column in order to incrementally refresh AVG(X). It requires both SUM(X) and COUNT(X) columns in order to in refresh STDDEV(X) or VARIANCE(X)

Solution

Make sure that the required columns are part of the summary definition if incremental refresh capability is desired.