Enterprise Database Consolidation with Exadata: A Real-World Case Study

Keywords: Oracle database consolidation, Exadata Cloud@Customer, performance tuning, CDB/PDB, Oracle RAC, capacity planning

This post is based on notes from one of my migration projects for a major financial institution. The institution aimed to simplify its sprawling on-premise database landscape with an ambitious goal: to consolidate over 500 critical Oracle databases onto Exadata Cloud@Customer (ExaCC) with minimal disruption. This was a multi-faceted and multi phased project and this migration was part of one phase only.

Initial Challenges

Before the transformation, the IT environment was fragmented:

• 200+ non-CDB 12c instances across scattered bare-metal servers
• Licensing overhead from underutilized hardware
• End-of-support risks for Oracle 12.1
• Poor CPU/memory utilization and inconsistent backups
• Performance spikes during peak windows

Sizing & CPU Planning Strategy

Proper sizing was important part to avoid oversubscription. The approach followed was:

• Collected peak 8-hour CPU stats (avg. 70% of 8 vCPUs per DB)
• Added a diversity factor (typically 0.6–0.7 for mixed workloads)
• Considered consolidation overhead (~15%)
• Accounted for PDB/tenant isolation
• Calculated total vCPU requirement and mapped to ¼ rack ExaCC (X9M)

The base line or example calculation used: 100 CDBs with 3 PDBs each → ~400 vCPU consolidated → 2 x ¼ rack ExaCC nodes (based on max 112 OCPUs per node)

Migration Strategy

Tools Used:

• RMAN for full/incremental backup migration
• Oracle Data Pump for schema lift & shift
• Cross Platform Transportable Tablespaces
• Oracle Golden-Gate for live replication (for custom schema and zero downtime requirement)

Architecture Evolution:

• Shift to Container Databases (CDB)
• High Availability with Oracle RAC & Data Guard
• Centralized patching, backups, and monitoring

Post-Migration Gains

• 30% lower licensing cost via CPU pooling and CDB structure
• Performance boosted: Avg. query times reduced by 40%
• Simplified hybrid cloud management with ExaCC
• Security & compliance with encrypted backups, audit trails, and restricted access zones

My Important Takeaways

• Used performance-based sizing, not 1:1 lift-and-shift
• CDB/PDB model helps maximize consolidation
• Combine diversity factor + overhead buffer for safe capacity planning
• ExaCC is ideal for regulated environments needing on-premise control + cloud agility

Got a similar project in mind? Contact me via LinkedIn or leave a comment!