ASA SQL User's Guide
Query Optimization and Execution
Query execution algorithms
Join algorithms are required when more than one table appears in the FROM clause. You cannot specify which join algorithm is used—the choice is made by the optimizer.
Nested loops join
Nested loops semijoin
Nested block join and sorted block
Hash join
Hash semijoin
Hash antisemijoin
Merge join
Recursive hash join
Recursive left outer hash join