Diagnose and Fix Query-Planner Misestimates in a FinTech Warehouse
Overview
What this challenge is about.
Diagnose and Fix Query-Planner Misestimates in a FinTech Warehouse. Expert-level challenge in analysis. Analyzing real datasets and building models that driv...
The Brief
What you'll do, and what you'll demonstrate.
Diagnose 6 planner-misestimate-driven slow queries on a 4.2 TB PostgreSQL warehouse, fix them, and write a tuning playbook the team can reuse.
This is not a data exercise. It is the work an analyst does when stakeholders need answers from messy data. That distinction matters to every hiring manager who has seen candidates describe statistical methods and none who have extracted insight from messy, real-world data.
When you finish, you will have something most graduates do not: a real-world deliverable, verified by Ewance, that you can show to a hiring manager and say "I did this. Here is the proof."
Earning criteria — what you'll demonstrate
- Read EXPLAIN (ANALYZE, BUFFERS) deeply enough to spot misestimates
- Apply CREATE STATISTICS to correlated and dependent columns
- Validate fixes against non-target queries to prevent regression
- Write a tuning playbook that lasts beyond the immediate fix
Program Fit
Where this fits in your program.
Sharpens the same skills your degree expects you to demonstrate.
Advanced Database Systems
Master · Databases
Strong alignment
This challenge maps to Advanced Database Systems at the Master level. It sharpens the same practical skills your coursework expects — but in a real industry context with actual constraints and deliverables.
Skills
Skills you'll demonstrate.
Each one shows up on your verified credential.
- Query Optimization
Apply query optimization to solve real industry problems and demonstrate production-level capability.
- Postgresql Planner
Apply postgresql planner to solve real industry problems and demonstrate production-level capability.
- Extended Statistics
Apply extended statistics to solve real industry problems and demonstrate production-level capability.
- Explain Analyze
Apply explain analyze to solve real industry problems and demonstrate production-level capability.
- Performance Tuning
Apply performance tuning to solve real industry problems and demonstrate production-level capability.
- Regression Testing
Apply regression testing to solve real industry problems and demonstrate production-level capability.
Careers
Career paths this challenge builds toward
Completing this challenge demonstrates skills that transfer directly to these roles: