TO_APPROX_COUNT_DISTINCT takes as its input a detail containing information about an approximate distinct value count, and converts it to a NUMBER value.

For detail, specify a detail of type BLOB, which was created by the APPROX_COUNT_DISTINCT_DETAIL function or the APPROX_COUNT_DISTINCT_AGG function.


Refer to TO_APPROX_COUNT_DISTINCT: Examples for examples of using the TO_APPROX_COUNT_DISTINCT function in conjunction with the APPROX_COUNT_DISTINCT_DETAIL and APPROX_COUNT_DISTINCT_AGG functions.