High-Performance Analytics & Columnar Databases

The Context Switch Tax

When running scan-heavy queries on massive local datasets, profiling reveals a counter-intuitive bottleneck: the system often behaves as CPU-bound, but CPU metrics do not reach maximum capacity. This is caused by the astronomical number of context switches and interrupt requests required to coordinate and fetch pages from disk into memory.

By intercepting standard POSIX reads, your data plane bypasses the kernel's page cache and interrupt handler logic. This effectively reclaims the system CPU time previously wasted on context switching, allowing the database's execution engine to dedicate its compute cycles exclusively to data aggregation and filtering.