This article explains why Vertica may choose different redistribution methods for the outer input of a hash join—RESEGMENT (LOCAL ROUND ROBIN) vs. RESEGMENT. The decision is influenced by system resource availability at query execution time.
Environment
- Vertica Analytics Platform
- Hash join operations
- Resource pools and query optimizer behavior
Situation
A user observed that Vertica sometimes uses RESEGMENT (LOCAL ROUND ROBIN) and other times uses RESEGMENT for the outer input of a hash join. This difference affects how data is redistributed across nodes during query execution.
