[ARROW-5409] [C++] Improvement for IsIn Kernel when right array is small

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: C++
• Labels: good-first-issue
• External issue URL: https://github.com/apache/arrow/issues/21863
• Assignee: Unassigned
• Reporter: Preeti Suman
• Created: 23/May/19 20:15
• Updated: 11/Jan/23 07:40

Description

The core of the algorithm (as python) is 

for i, elem in array:
  output[i] = (elem in memo_table)

 Often the right operand list will be very small, in this case, the hashtable should be replaced with a constant vector. 

Issue Links

• Dependency: ARROW-5394 [C++] Benchmarks for IsIn Kernel