ClickHouse Index Explorer
An exploratory tool for understanding data layout, index behavior, and query performance.
Overview
An exploratory tool that makes ClickHouse table structure and query behavior easier to inspect without requiring every user to understand the storage engine in depth.
Problem
Query performance depends heavily on sort order, partitioning, data distribution, and skipping indexes. Those relationships are easy to miss when the available information is split across system tables and query plans.
Approach
The explorer organizes relevant metadata around practical questions: how data is laid out, which parts a query reads, and where an index can or cannot reduce work.
Architecture
A small read-only analysis layer gathers public ClickHouse metadata and normalizes it into table, part, and query views. The interface emphasizes explanation over automatic tuning.
Implementation
The initial scope focuses on deterministic metadata queries and concise interpretations. Potential recommendations include their assumptions so users can verify them against their workload.
Impact
The project aims to shorten the path from a slow query to a testable hypothesis while keeping all database changes under the operator’s control.
Lessons Learned
Database tooling is most trustworthy when it exposes evidence and uncertainty. A clear explanation is more durable than a one-click optimization.