Search query without specifying the field

Elastic Stack Elasticsearch
1

Hi,
How do you perform search query without specifying the field, basically to perform search on all fields.
I realize that _all is removed in elasticsearch 7.
I tried query_string with out fields but i get query_shard_exception and search_phase_execution_exception
Is there any other way?

Thanks

2

_all is deprecated. But you can use copy_to to create custom _all fields.
See: https://www.elastic.co/guide/en/elasticsearch/reference/6.8/copy-to.html