WARLOCK: A Data Allocation Tool for Parallel Warehouses

We present the WARLOCK tool to automatically determine a parallel data warehouse’s allocation to disk. This GUIequipped tool is implemented in Java and utilizes an internal cost model and heuristics to determine a disk allocation minimizing both I/O work and query response times. WARLOCK recommends a ranked list of fragmentation candidates, a detailed query performance analysis and a tailored physical allocation scheme for relational star schemas and bitmap indexes. It supports multi-dimensional fragmentations and can deal with data skew for parallel data warehouses based on a Shared Everything or Shared Disk architecture.