55 lines
1.9 KiB
Markdown
55 lines
1.9 KiB
Markdown
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---
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layout: clqms-post.njk
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tags: clqms
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title: "Database Design Roast: Zai"
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date: 2025-12-09
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order: 9
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---
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# The Database Design from Hell: A Comprehensive Roast
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Or: Why your current project makes you want to quit.
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## 1. The "Value Set" Disaster (The God Table)
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Storing every enumeration in one giant generic table.
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- **No Identity:** Can't change "M" to "Male" without breaking FKs
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- **Performance Killer:** Scans 10,000 rows for simple dropdowns
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- **Zero Integrity:** Can delete values used for Critical Status
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## 2. The "Organization" Nightmare
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Building a database for a Laboratory, not the United Nations. Mixing external business logic (Sales) with internal operational logic (Lab Science).
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## 3. The "Location" & "LocationAddress" Split
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Forcing a JOIN for every label. For mobile locations (Home Care), address is vital. For static locations (Bed 1), address is meaningless. **Pointless normalization.**
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## 4. The "Doctor" vs "Contact" Loop
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To get a Doctor's name, do you query Doctor or Contact? If Dr. Smith retires, do you delete the Doctor record? Then you lose his Contact info. **This design doesn't separate Role from Entity.**
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## 5. Patient Data: The Actual Hell
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- **Blood Bags are not Humans:** Patient table has DOB (Required) and BloodType (Required). Blood Bag has NULL DOB. Created a "Sparse Table."
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- **The "Link/Unlink" Suicide Pact:** Database loses history of why patients were unlinked
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## 6. Test Data: The Maze of Redundancy
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testdef, testdefsite, testdeftech, testgrp, refnum, reftxt, fixpanel.
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- Glucose defined in 50 different places
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- Profile, Functional Procedure, Superset all stored as "Tests in a Group"
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- refnum vs reftxt split doubles JOINs for no reason
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---
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## Summary
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This document is a "Jack of All Trades, Master of None." CRM + ERP + Billing + Lab System in one poorly normalized schema. **Data Hell.**
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---
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*Do not build this "as is." You will spend 5 years writing SQL Scripts to patch the holes.*
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