BITMAP_COUNT is a scalar function that returns the 1-bit count for the input bitmap.

The argument expr is of type BLOB.

It returns a NUMBER representing the count of bits set in its input.

If expr is NULL, it returns 0.


The argument must be of type BLOBtype. The argument is expected to be a bitmap produced by BITMAP_CONSTRUCT_AGG or, recursively, by BITMAP_OR_AGG. Any other input results in ORA-62578:
62578, 00000, "The input is not a valid bitmap produced by BITMAP COUNT DISTINCT related operators."
// *Cause: An attempt was made to pass a bitmap that was not produced by one of the BITMAP COUNT DISTINCT operators.
// *Action: Only pass bitmaps constructed via BITMAP_CONSTRUCT_AGG or BITMAP_OR_AGG to BITMAP COUNT DISTINCT related operators.