[IMPALA-10558] Implement ds_theta_exclude() function.

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Impala 4.0.0
• Component/s: Backend, Frontend
• Epic Link: datasketches-theta
• Target Version: Impala 4.0.0
• Epic Color: ghx-label-11
• Assignee: Fucun Chu
• Reporter: Fucun Chu
• Created: 02/Mar/21 12:26
• Updated: 23/Mar/21 13:54
• Resolved: 23/Mar/21 13:54

Description

This function receives two strings that are serialized Apache DataSketches Theta sketches. Computes the a-not-b set operation given two sketches of same or different column.

Example:

select ds_theta_estimate(ds_theta_exclude(sketch1, sketch2)) from sketch_tbl;
+-------------------------------------------------------+
| ds_theta_estimate(ds_theta_exclude(sketch1, sketch2)) |
+-------------------------------------------------------+
| 5                                                     |
+-------------------------------------------------------+