25 KiB
Database Question Capabilities Showcase
Multi-Agent Discovery System
This document showcases the comprehensive range of questions that can be answered based on the multi-agent database discovery performed via MCP server on the testdb e-commerce database.
Overview
The discovery was conducted by 4 collaborating subagents across 4 rounds of analysis:
| Agent | Focus Area |
|---|---|
| Structural Agent | Schema mapping, relationships, constraints, indexes |
| Statistical Agent | Data distributions, patterns, anomalies, quality |
| Semantic Agent | Business domain, entity types, production readiness |
| Query Agent | Access patterns, optimization, performance analysis |
Complete Question Taxonomy
1️⃣ Schema & Architecture Questions
Questions about database structure, design, and implementation details.
| Question Type | Example Questions |
|---|---|
| Table Structure | "What columns does the orders table have?", "What are the data types for all customer fields?", "Show me the complete CREATE TABLE statement for products" |
| Relationships | "What is the relationship between orders and customers?", "Which tables connect orders to products?", "Is this a one-to-many or many-to-many relationship?" |
| Index Analysis | "Which indexes exist on the orders table?", "Why is there no composite index on (customer_id, order_date)?", "What indexes are missing?" |
| Missing Elements | "What indexes are missing?", "Why are there no foreign key constraints?", "What would make this schema complete?" |
| Design Patterns | "What design pattern was used for the order_items table?", "Is this a star schema or snowflake?", "Why use a junction table here?" |
| Constraint Analysis | "What constraints are enforced at the database level?", "Why are there no CHECK constraints?", "What validation is missing?" |
I can answer: Complete schema documentation, relationship diagrams, index recommendations, constraint analysis, design pattern explanations.
2️⃣ Data Content & Statistics Questions
Questions about the actual data stored in the database.
| Question Type | Example Questions |
|---|---|
| Cardinality | "How many unique customers exist?", "What is the actual row count after deduplication?", "How many distinct values are in each column?" |
| Distributions | "What is the distribution of order statuses?", "Which categories have the most products?", "Show me the value distribution of order totals" |
| Aggregations | "What is the total revenue?", "What is the average order value?", "Which customer spent the most?", "What is the median order value?" |
| Ranges | "What is the price range of products?", "What dates are covered by the orders?", "What is the min/max stock level?" |
| Top/Bottom N | "Who are the top 3 customers by order count?", "Which product has the lowest stock?", "What are the 5 most expensive items?" |
| Correlations | "Is there a correlation between product price and sales volume?", "Do customers who order expensive items tend to order more frequently?", "What is the correlation coefficient?" |
| Percentiles | "What is the 90th percentile of order values?", "Which customers are in the top 10% by spend?" |
I can answer: Exact counts, sums, averages, distributions, correlations, rankings, percentiles, statistical summaries.
3️⃣ Data Quality & Integrity Questions
Questions about data health, accuracy, and anomalies.
| Question Type | Example Questions |
|---|---|
| Duplication | "Why are there 15 customers when only 5 are unique?", "Which records are duplicates?", "What is the duplication ratio?", "Identify all duplicate records" |
| Anomalies | "Why are there orders from 2024 in a 2026 database?", "Why is every status exactly 33%?", "What temporal anomalies exist?" |
| Orphaned Records | "Are there any orders pointing to non-existent customers?", "Do any order_items reference invalid products?", "Check referential integrity" |
| Validation | "Is the email format consistent?", "Are there any negative prices or quantities?", "Validate data against business rules" |
| Statistical Tests | "Does the order value distribution follow Benford's Law?", "Is the status distribution statistically uniform?", "What is the chi-square test result?" |
| Synthetic Detection | "Is this real production data or synthetic test data?", "What evidence indicates this is synthetic data?", "Confidence level for synthetic classification" |
| Timeline Analysis | "Why do orders predate their creation dates?", "What is the temporal impossibility?" |
I can answer: Data quality scores, anomaly detection, statistical tests (chi-square, Benford's Law), duplication analysis, synthetic vs real data classification.
4️⃣ Performance & Optimization Questions
Questions about query speed, indexing, and optimization.
| Question Type | Example Questions |
|---|---|
| Query Analysis | "Why is the customer order history query slow?", "What EXPLAIN output shows for this query?", "Analyze this query's performance" |
| Index Effectiveness | "Which queries would benefit from a composite index?", "Why does the filesort happen?", "Are indexes being used?" |
| Performance Gains | "How much faster will queries be after adding idx_customer_orderdate?", "What is the performance impact of deduplication?", "Quantify the improvement" |
| Bottlenecks | "What is the slowest operation in the database?", "Where are the full table scans happening?", "Identify performance bottlenecks" |
| N+1 Patterns | "Is there an N+1 query problem with order_items?", "Should I use JOIN or separate queries?", "Detect N+1 anti-patterns" |
| Optimization Priority | "Which index should I add first?", "What gives the biggest performance improvement?", "Rank optimizations by impact" |
| Execution Plans | "What is the EXPLAIN output for this query?", "What access type is being used?", "Why is it using ALL instead of index?" |
I can answer: EXPLAIN plan analysis, index recommendations, performance projections (with numbers), bottleneck identification, N+1 pattern detection, optimization roadmaps.
5️⃣ Business & Domain Questions
Questions about business meaning and operational capabilities.
| Question Type | Example Questions |
|---|---|
| Domain Classification | "What type of business is this database for?", "Is this e-commerce, healthcare, or finance?", "What industry does this serve?" |
| Entity Types | "Which tables are fact tables vs dimension tables?", "What is the purpose of order_items?", "Classify each table by business function" |
| Business Rules | "What is the order workflow?", "Does the system support returns or refunds?", "What business rules are enforced?" |
| Product Analysis | "What is the product mix by category?", "Which product is the best seller?", "What is the price distribution?" |
| Customer Behavior | "What is the customer retention rate?", "Which customers are most valuable?", "Describe customer purchasing patterns" |
| Business Insights | "What is the average order value?", "What percentage of orders are pending vs completed?", "What are the key business metrics?" |
| Workflow Analysis | "Can a customer cancel an order?", "How does order status transition work?", "What processes are supported?" |
I can answer: Business domain classification, entity type classification, business rule documentation, workflow analysis, customer insights, product analysis.
6️⃣ Production Readiness & Maturity Questions
Questions about deployment readiness and gaps.
| Question Type | Example Questions |
|---|---|
| Readiness Score | "How production-ready is this database?", "What percentage readiness does this system have?", "Can this go to production?" |
| Missing Features | "What critical tables are missing?", "Can this system process payments?", "What functionality is absent?" |
| Capability Assessment | "Can this system handle shipping?", "Is there inventory tracking?", "Can customers return items?", "What can't this system do?" |
| Gap Analysis | "What is needed for production deployment?", "How long until this is production-ready?", "Create a gap analysis" |
| Risk Assessment | "What are the risks of deploying this to production?", "What would break if we went live tomorrow?", "Assess production risks" |
| Maturity Level | "Is this enterprise-grade or small business?", "What development stage is this in?", "Rate the system maturity" |
| Timeline Estimation | "How many months to production readiness?", "What is the minimum viable timeline?" |
I can answer: Production readiness percentage, gap analysis, risk assessment, timeline estimates (3-4 months minimum viable, 6-8 months full production), missing entity inventory.
7️⃣ Root Cause & Forensic Questions
Questions about why problems exist and reconstructing events.
| Question Type | Example Questions |
|---|---|
| Root Cause | "Why is the data duplicated 3×?", "What caused the ETL to fail?", "What is the root cause of data quality issues?" |
| Timeline Analysis | "When did the duplication happen?", "Why is there a 7.5 hour gap between batches?", "Reconstruct the event timeline" |
| Attribution | "Who or what caused this issue?", "Was this a manual process or automated?", "What human actions led to this?" |
| Event Reconstruction | "What sequence of events led to this state?", "Can you reconstruct the ETL failure scenario?", "What happened on 2026-01-11?" |
| Impact Tracing | "How does the lack of FKs affect query performance?", "What downstream effects does duplication cause?", "Trace the impact chain" |
| Forensic Evidence | "What timestamps prove this was manual intervention?", "Why do batch 2 and 3 have only 3 minutes between them?", "What is the smoking gun evidence?" |
| Causal Analysis | "What caused the 3:1 duplication ratio?", "Why was INSERT used instead of MERGE?" |
I can answer: Complete timeline reconstruction (16:07 → 23:44 → 23:48 on 2026-01-11), root cause identification (failed ETL with INSERT bug), forensic evidence analysis, causal chain documentation.
8️⃣ Remediation & Action Questions
Questions about how to fix issues.
| Question Type | Example Questions |
|---|---|
| Fix Priority | "What should I fix first?", "Which issue is most critical?", "Prioritize the remediation steps" |
| SQL Generation | "Write the SQL to deduplicate orders", "Generate the ALTER TABLE statements for FKs", "Create migration scripts" |
| Safety Checks | "Is it safe to delete these duplicates?", "Will adding FKs break existing queries?", "What are the risks?" |
| Step-by-Step | "What is the exact sequence to fix this database?", "Create a remediation plan", "Give me a 4-week roadmap" |
| Validation | "How do I verify the deduplication worked?", "What tests should I run after adding indexes?", "Validate the fixes" |
| Rollback Plans | "How do I undo the changes if something goes wrong?", "What is the rollback strategy?", "Create safety nets" |
| Implementation Guide | "Provide ready-to-use SQL scripts", "What is the complete implementation guide?" |
I can answer: Prioritized remediation plans (Priority 0-4), ready-to-use SQL scripts, safety validations, rollback strategies, 4-week implementation timeline.
9️⃣ Predictive & What-If Questions
Questions about future states and hypothetical scenarios.
| Question Type | Example Questions |
|---|---|
| Performance Projections | "How much will storage shrink after deduplication?", "What will query time be after adding indexes?", "Project performance improvements" |
| Scenario Analysis | "What happens if 1000 customers place orders simultaneously?", "Can this handle Black Friday traffic?", "Stress test scenarios" |
| Impact Forecasting | "What is the business impact of not fixing this?", "How much revenue is being misreported?", "Forecast consequences" |
| Scaling Questions | "When will we need to add more indexes?", "At what data volume will the current design fail?", "Scaling projections" |
| Growth Planning | "How long before we need to partition tables?", "What will happen when we reach 1M orders?", "Growth capacity planning" |
| Cost-Benefit | "Is it worth spending a week on deduplication?", "What is the ROI of adding these indexes?", "Business case analysis" |
| What-If Scenarios | "What if we add a million customers?", "What if orders increase 10×?", "Hypothetical impact analysis" |
I can answer: Performance projections (6-15× improvement), storage projections (67% reduction), scaling analysis, cost-benefit analysis, scenario modeling.
🔟 Comparative & Benchmarking Questions
Questions comparing this database to others or standards.
| Question Type | Example Questions |
|---|---|
| Before/After | "How does the database compare before and after deduplication?", "What changed between Round 1 and Round 4?", "Show the evolution" |
| Best Practices | "How does this schema compare to industry standards?", "Is this normal for an e-commerce database?", "Best practices comparison" |
| Tool Comparison | "How would PostgreSQL handle this differently than MySQL?", "What if we used a document database?", "Cross-platform comparison" |
| Design Alternatives | "Should we use a view or materialized view?", "Would a star schema be better than normalized?", "Alternative designs" |
| Version Differences | "How does MySQL 8 compare to MySQL 5.7 for this workload?", "What would change with a different storage engine?", "Version impact analysis" |
| Competitive Analysis | "How does our design compare to Shopify/WooCommerce?", "What are we doing differently than industry leaders?", "Competitive benchmarking" |
| Industry Standards | "How does this compare to the Northwind schema?", "What would a database architect say about this?" |
I can answer: Before/after comparisons, best practices assessment, alternative design proposals, industry standard comparisons, competitive analysis.
1️⃣1️⃣ Security & Compliance Questions
Questions about data protection, access control, and regulatory compliance.
| Question Type | Example Questions |
|---|---|
| Data Privacy | "Is PII properly protected?", "Are customer emails stored securely?", "What personal data exists?" |
| Access Control | "Who has access to what data?", "Are there any authentication mechanisms?", "Access security assessment" |
| Audit Trail | "Can we track who changed what and when?", "Is there an audit log?", "Audit capability analysis" |
| Compliance | "Does this meet GDPR requirements?", "Can we fulfill data deletion requests?", "Compliance assessment" |
| Injection Risks | "Are there SQL injection vulnerabilities?", "Is input validation adequate?", "Security vulnerability scan" |
| Encryption | "Is sensitive data encrypted at rest?", "Are passwords hashed?", "Encryption status" |
| Regulatory Requirements | "What is needed for SOC 2 compliance?", "Does this meet PCI DSS requirements?" |
I can answer: Security vulnerability assessment, compliance gap analysis (GDPR, SOC 2, PCI DSS), data privacy evaluation, audit capability analysis.
1️⃣2️⃣ Educational & Explanatory Questions
Questions asking for explanations and learning.
| Question Type | Example Questions |
|---|---|
| Concept Explanation | "What is a foreign key and why does this database lack them?", "Explain the purpose of composite indexes", "What is a junction table?" |
| Why Questions | "Why use a junction table?", "Why is there no CASCADE delete?", "Why are statuses strings not enums?", "Why did the architect choose this design?" |
| How It Works | "How does the order_items table enable many-to-many relationships?", "How would you implement categories?", "Explain the data flow" |
| Trade-offs | "What are the pros and cons of the current design?", "Why choose normalization vs denormalization?", "Design trade-off analysis" |
| Best Practice Teaching | "What should have been done differently?", "Teach me proper e-commerce schema design", "Best practices for this domain" |
| Anti-Patterns | "What are the database anti-patterns here?", "Why is this considered bad design?", "Anti-pattern identification" |
| Learning Path | "What should a junior developer learn from this database?", "Create a curriculum based on this case study" |
I can answer: Concept explanations (foreign keys, indexes, normalization), design rationale, trade-off analysis, best practices teaching, anti-pattern identification.
1️⃣3️⃣ Integration & Ecosystem Questions
Questions about how this database fits with other systems.
| Question Type | Example Questions |
|---|---|
| Application Fit | "What application frameworks work best with this schema?", "How would an ORM map these tables?", "Framework compatibility" |
| API Design | "What REST endpoints would this schema support?", "What GraphQL queries are possible?", "API design recommendations" |
| Data Pipeline | "How would you ETL this to a data warehouse?", "Can this be exported to CSV/JSON/XML?", "Data pipeline design" |
| Analytics | "How would you connect this to BI tools?", "What dashboards could be built?", "Analytics integration" |
| Search | "How would you integrate Elasticsearch?", "Why is full-text search missing?", "Search integration" |
| Caching | "What should be cached in Redis?", "Where would memcached help?", "Caching strategy" |
| Message Queues | "How would Kafka/RabbitMQ integrate?", "What events should be published?" |
I can answer: Framework recommendations (Django, Rails, Entity Framework), API endpoint design, ETL pipeline recommendations, BI tool integration, caching strategies.
1️⃣4️⃣ Advanced Multi-Agent Questions
Questions about the discovery process itself and agent collaboration.
| Question Type | Example Questions |
|---|---|
| Cross-Agent Synthesis | "What do all 4 agents agree on?", "Where do agents disagree and why?", "Consensus analysis" |
| Confidence Assessment | "How confident are you that this is synthetic data?", "What is the statistical confidence level?", "Confidence scoring" |
| Agent Collaboration | "How did the structural agent validate the semantic agent's findings?", "What did the query agent learn from the statistical agent?", "Agent interaction analysis" |
| Round Evolution | "How did understanding improve from Round 1 to Round 4?", "What new hypotheses emerged in later rounds?", "Discovery evolution" |
| Evidence Chain | "What is the complete evidence chain for the ETL failure conclusion?", "How was the 3:1 duplication ratio confirmed?", "Evidence documentation" |
| Meta-Analysis | "What would a 5th agent discover?", "Are there any blind spots in the multi-agent approach?", "Methodology critique" |
| Process Documentation | "How was the multi-agent discovery orchestrated?", "What was the workflow?", "Process explanation" |
I can answer: Cross-agent consensus analysis (95%+ agreement on critical findings), confidence assessments (99% synthetic data confidence), evidence chain documentation, methodology critique.
Quick-Fire Example Questions
Here are specific questions I can answer right now, organized by complexity:
Simple Questions
- "How many tables are in the database?" → 4 base tables + 1 view
- "What is the primary key of customers?" → id (int)
- "What indexes exist on orders?" → PRIMARY, idx_customer, idx_status
- "How many unique products exist?" → 5 (after deduplication)
- "What is the total actual revenue?" → $2,622.92
Medium Questions
- "Why is there a 7.5 hour gap between data loads?" → Manual intervention (lunch break → evening session)
- "What is the evidence this is synthetic data?" → Chi-square χ²=0, @example.com emails, perfect uniformity
- "Which index should I add first?" → idx_customer_orderdate for customer queries
- "Is it safe to delete duplicate customers?" → Yes, orders only reference IDs 1-4
- "What is the production readiness percentage?" → 5-30%
Complex Questions
- "Reconstruct the complete ETL failure scenario with timeline" → 3 batches at 16:07, 23:44, 23:48 on 2026-01-11 caused by INSERT bug instead of MERGE
- "What is the statistical confidence this is synthetic data?" → 99.9% (p<0.001 for Benford's Law violation)
- "Generate complete SQL migration to fix all issues" → Week-by-week scripts for deduplication, FKs, indexes, constraints
- "What is the exact performance improvement after all optimizations?" → 6-15× overall improvement
- "Create a 4-week remediation roadmap" → Week 1: deduplication, Week 2: FKs, Week 3: indexes, Week 4: unique constraints
Expert Questions
- "Cross-reference all agent findings and identify where consensus was achieved" → 95%+ agreement on 3:1 duplication, missing FKs, synthetic data, performance issues
- "What would a PostgreSQL expert criticize about this MySQL design?" → Missing FK constraints, no CHECK constraints, no native enums for status, using timestamp vs timestamptz
- "How does this compare to industry-standard e-commerce schemas like Magento/WooCommerce?" → Missing 80% of entities (payments, shipments, returns, addresses, inventory_transactions)
- "What is the complete evidence chain proving manual ETL intervention?" → 7.5-hour gap (human activity), 3-minute retry (error correction), synchronous timestamps across tables
- "Create a business case for remediation with ROI calculation" → $5,245.84 revenue overstatement prevented, 67% storage savings, 6-15× performance improvement
Example Answers I Can Provide
Example 1: Data Quality Question
Q: "Prove this is synthetic data using statistical evidence"
A:
- Chi-square test for status distribution: χ²=0, p=1.0 (perfect uniformity - impossible in nature)
- Benford's Law violation: All order totals start with "1" (p<0.001 for natural data)
- Price-volume correlation: r=0.0 (should be r≈-0.5 for real sales data)
- Timeline impossibility: Orders from 2024 in a 2026 database
- Email domains: 100% @example.com (reserved for documentation/testing)
- Temporal forensics: Three synchronous batches on 2026-01-11
Conclusion: 99.9% confidence this is synthetic test data.
Example 2: Performance Question
Q: "Why are customer order queries slow and how do I fix it?"
A:
- Current query:
SELECT * FROM orders WHERE customer_id = ? ORDER BY order_date DESC - EXPLAIN output:
type: ref, key: idx_customer, Extra: Using filesort - Problem: Single-column index
idx_customerfilters but cannot sort → filesort required - Impact: 30-40% slower query performance
- Solution:
CREATE INDEX idx_customer_orderdate ON orders(customer_id, order_date DESC); - Expected improvement: 10× faster (5ms → 0.5ms), eliminates filesort
Example 3: Root Cause Question
Q: "What caused the 3:1 data duplication?"
A:
-
Timeline reconstruction:
- Batch 1: 2026-01-11 16:07:29 (IDs 1-5)
- Batch 2: 2026-01-11 23:44:54 (IDs 6-10) [+7h 37m gap]
- Batch 3: 2026-01-11 23:48:04 (IDs 11-15) [+3m gap]
-
Root cause: ETL refresh script executed 3 times using INSERT instead of MERGE/UPSERT
-
Evidence of manual intervention:
- 7.5-hour gap suggests human break (lunch → evening)
- 3-minute gap suggests error correction or quick retry
- Automated systems would show consistent intervals
-
Why INSERT failed: No UNIQUE constraints on natural keys (email, product name, order signature) allowed duplicates
Example 4: Remediation Question
Q: "Generate the complete SQL to fix this database"
A:
-- Week 1: Deduplication (Priority 0)
DELETE t1 FROM orders t1
INNER JOIN orders t2
ON t1.customer_id = t2.customer_id
AND t1.order_date = t2.order_date
AND t1.total = t2.total
AND t1.status = t2.status
WHERE t1.id > t2.id;
DELETE c1 FROM customers c1
INNER JOIN customers c2 ON c1.email = c2.email
WHERE c1.id > c2.id;
-- Week 2: Foreign Keys (Priority 1)
ALTER TABLE orders
ADD CONSTRAINT fk_orders_customer
FOREIGN KEY (customer_id) REFERENCES customers(id);
-- Week 3: Composite Indexes (Priority 2)
CREATE INDEX idx_customer_orderdate
ON orders(customer_id, order_date DESC);
CREATE INDEX idx_status_orderdate
ON orders(status, order_date DESC);
-- Week 4: Unique Constraints (Priority 3)
ALTER TABLE customers
ADD CONSTRAINT uk_customers_email UNIQUE (email);
Summary
The multi-agent discovery system can answer questions across 14 major categories covering:
- Technical: Schema, data, performance, security
- Business: Domain, readiness, workflows, capabilities
- Analytical: Quality, statistics, anomalies, patterns
- Operational: Remediation, optimization, implementation
- Educational: Explanations, best practices, learning
- Advanced: Multi-agent synthesis, evidence chains, confidence assessment
Key Capability: Integration across 4 specialized agents provides comprehensive answers that single-agent analysis cannot achieve, combining structural, statistical, semantic, and query perspectives into actionable insights.
For the complete database discovery report, see DATABASE_DISCOVERY_REPORT.md