The join-plan directives influence how the database server joins two tables in a query.
The following directives influence the join plan between two tables:
Use the listed tables as the inner table in a nested-loop join.
Access the listed tables with a hash join. You can also choose whether the table is used to create the hash table or to probe the hash table.
Do not use the listed tables as the inner table in a nested-loop join. A table listed with this directive can still participate in a nested-loop join as an outer table.
Do not access the listed tables with a hash join. Optionally, you can allow a hash join but restrict the table from being the one that is probed or the table from which the hash table is built.