reading Creating new materializations | dbt Developer Hub (getdbt.com)
there is an explicit example on using one for RS as
{% materialization my_materialization_name, adapter='redshift' %}
but then it’s looks not really needed reading a couple of lines below I read:
dbt's ability to dynamically pick the correct materialization based on the active database target is called multiple dispatch. ...
so it’s not really clear if was necessary or not to use it - I am suing RS 
so I am quite interested and I’ve got some Serializable isolation violation on table even using thread=1 in dbt build 