Dear aaron-nimocks, thank you very much for your reply. I can understand what you said.In fact, I am new to Elasticsearch and have no big goals to achieve.
The reason I ask this question is because when I read the official elasticsearch documentation (v7.10), copy_to confuses me.
I have experimented with two situations myself.
In the first, I set the target field of the copy_to to keyword type ,and the index can be created successfully, but the results cannot be searched according to my expectations.
In the second case, I set the target type of the copy_to field to search_as_you_type type,and the index can be created successfully, and the results can be searched as expected.
The experiment process can be found in the following document: https://github.com/ZhangDi-d/elasticsearch-demo/blob/main/copy_to.md
So I fell into a huge confusion. Did i do something wrong, or the copy_to field does have type restrictions? I hope my description is clear and I hope you can give me some advice.
Thanks.