Default sort order if not specified?
Interviewer Expectations for this Question
01
Core Competency
Assesses fundamental understanding of SQL & Databases conventions, runtime behavior, and memory/performance considerations.
02
Evaluation Criteria
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
Comprehensive Model Answer
Verified Solution
If no direction keyword is specified in an ORDER BY clause, the default sort order is ASC (Ascending):
-- These two queries produce identical ordering:
SELECT * FROM Customers ORDER BY LastName;
SELECT * FROM Customers ORDER BY LastName ASC;
### Important Database Reality:
In relational theory, tables are unordered sets. If a SQL query has no ORDER BY clause at all, the database makes no guarantees about the order of returned rows—rows may return in different sequences based on query execution plans or parallel worker threads.
Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
- Demonstrate real-world trade-offs: Discuss where this approach excels and when you would avoid it in production systems.
- Discuss complexity & edge cases: Proactively explain time/space complexity or boundary conditions (null values, scale limits).
- Prepare for interviewer follow-ups: Technical hiring panels frequently probe deeper into concurrency, backward compatibility, or alternative libraries.