[IMPALA-10687] Implement ds_cpc_union() function

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Impala 4.1.0
• Epic Link: DataSketches CPC support
• Epic Color: ghx-label-7
• Assignee: Fucun Chu
• Reporter: Fucun Chu
• Created: 30/Apr/21 08:41
• Updated: 26/Jun/21 10:26
• Resolved: 26/Jun/21 10:26

Description

Similarly to https://issues.apache.org/jira/browse/IMPALA-9633 DataSketches CPC also has union functionality.

ds_cpc_union() expects a dataset of STRINGs (e.g. column of a table) that represents serialized CPC sketches and returns a single STRING that is the received sketches unioned and serialized.