Does MERGE statement can benefit from BigQuery field clustering?

Question

I merge two tables in Google BiqQuery ON several STRING fields

(field_1, field_2, field_3, field_4).

Will MERGE query be more efficient if I cluster my tables on field_1? field_1, field_2? All 4 fields?

Answer 1

There is no optimization (yet) for joining clustered tables using merge join instead of hash join, so no. Clustering provides significant performance improvements with filters and aggregations using the cluster keys, however.