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PROFESSIONAL-DATA-ENGINEER · Question #3
You designed a database for patient records as a pilot project to cover a few hundred patients in three clinics. Your design used a single database table to represent all patients and their visits, an
The correct answer is C. Normalize the master patient-record table into the patient table and the visits table, and create other necessary tables to avoid self-join.. Explanation/Reference: It provides the least amount of inconvenience over using pre-specified date ranges or one table per clinic while also increasing performance due to avoiding self-
Submitted by femi9· Mar 30, 2026Designing data processing systems
Question
You designed a database for patient records as a pilot project to cover a few hundred patients in three clinics. Your design used a single database table to represent all patients and their visits, and you used self-joins to generate reports. The server resource utilization was at 50%. Since then, the scope of the project has expanded. The database must now store 100 times more patient records. You can no longer run the reports, because they either take too long or they encounter errors with insufficient compute resources. How should you adjust the database design?
Options
- AAdd capacity (memory and disk space) to the database server by the order of 200.
- BShard the tables into smaller ones based on date ranges, and only generate reports with prespecified date ranges.
- CNormalize the master patient-record table into the patient table and the visits table, and create other necessary tables to avoid self-join.
- DPartition the table into smaller tables, with one for each clinic. Run queries against the smaller table pairs, and use unions for consolidated reports.
How the community answered
(23 responses)- A22% (5)
- B13% (3)
- C61% (14)
- D4% (1)
Explanation
Explanation/Reference: It provides the least amount of inconvenience over using pre-specified date ranges or one table per clinic while also increasing performance due to avoiding self-
Topics
#database normalization#schema design#self-join elimination#scalability
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