APPROX_COUNT_DISTINCT_AGG takes as its input a column of details containing information about approximate distinct value counts, and enables you to perform aggregations of those counts.
detail, specify a column of details created by the
APPROX_COUNT_DISTINCT_DETAIL function or the
APPROX_COUNT_DISTINCT_AGG function. This column is of data type
You can specify this function in a
SELECT statement with a
BY clause to aggregate the information contained in the details within each group of rows and return a single detail for each group.
This function returns a
BLOB value, called a detail, which contains information about the count aggregations in a special format. You can store details returned by this function in a table or materialized view, and then again use the
APPROX_COUNT_DISTINCT_AGG function to further aggregate those details, or use the
TO_APPROX_COUNT_DISTINCT function to convert the detail values to human-readable
Refer to APPROX_COUNT_DISTINCT_AGG: Examples for examples of using the
APPROX_COUNT_DISTINCT_AGG function in conjunction with the