[BEAM-7358] Developing "GroupByMultiKey"

• Type: New Feature
• Status: Open
• Priority: P3
• Resolution: Unresolved
• Component/s: beam-model, sdk-ideas
• Assignee: Unassigned
• Reporter: Hyu Naoki
• Created: 20/May/19 04:42
• Updated: 04/Jun/22 01:49

Description

GroupByKey is useful, but it is difficult to express complex grouping conditions.

I propose the development of the function to group if there is a common term in even one of multiple keys.

Like this....

 

usage

 

List io = Arrays.asList(
KV.of(new MultiKey("A","C", "E"),"0"),
 KV.of(new MultiKey("A","D", "F"),"1"),
 KV.of(new MultiKey("B","D", "G"),"2"),
 KV.of(new MultiKey("H","J", "L"),"3"),
 KV.of(new MultiKey("I","K", "L"),"4"),
 KV.of(new MultiKey("M","C", "O"),"5"),
 KV.of(new MultiKey(null,null, "O"),"6"),
 KV.of(new MultiKey(null,null, null),"7")
);
p.apply(Create.of(io))
.apply(GroupByMultiKey.create(3))
.apply(new DebugPrintln());

 

 out put this

 

[KV{["A","C","E"],"0"},KV{["A","D","F"],"1"},KV{["B","D","G"],"2"},KV{["M","C","O"],"5"},KV{[null,null,"O"],"6"}]

[KV{["H","J","L"],"3"},KV{["I","K","L"],"4"}]

[KV{[null,null,null],"7"}]