BITMAP_CONSTRUCT_AGG

Syntax

Description of the illustration bitmap_construct_agg.gif

Purpose

BITMAP_CONSTRUCT_AGG is an aggregation function that operates on bit positions and returns the bitmap representation of the set of all input bit positions. It essentially maintains a bitmap and sets into it all the input bit positions. It returns the representation of the bitmap.

The argument expr is of type NUMBER.

The return type is of type BLOB.

If expr is NULL, the function returns NULL.

Restrictions

• The argument must be of NUMBER type. If the input value cannot be converted to a natural number, error ORA-62575 is raised:

  62575, 00000, "Invalid value has been passed to a BITMAP COUNT DISTINCT related operator."
  // *Cause: An attempt was made to pass an invalid value to a BITMAP COUNT DISTINCT operator.
  // *Action: Pass only natural number values to BITMAP_CONSTRUCT_AGG.

• If the bitmap exceeds the maximum value of a BLOB, you will see error ORA-62577:

62577, 00000, "The bitmap size exceeds maximum size of its SQL data type."
// *Cause: An attempt was made to construct a bitmap larger than its maximum SQL type size.
// *Action: Break the input to BITMAP_CONSTRUCT_AGG into smaller ranges.