This article explains why existing projections designed for a single-node Vertica cluster can cause performance issues on a multi-node cluster. It also provides guidance on using Database Designer (DBD) to optimize projections for proper segmentation and efficient query execution. Recommendation: Run Database Designer (DBD) on the affected workload to produce projections optimized for 3 nodes (proper segmentation, sort order, encodings, and buddy projections). Then redeploy and validate. Vertica DBD guide: https://docs.vertica.com/latest/en/getting-started/db-designer/
Environment
- Vertica Database
- Cluster expanded from 1 node to 3 nodes
- Existing projections largely unsegmented
Situation
After expanding a Vertica cluster from one node to three nodes, queries involving joins and aggregations became slower. Investigation revealed that existing projections were designed for a single-node environment and lacked segmentation.
