✔ PASS
Warehouse & Statistical
task_097_Q97_sargable_date_boundary_pruning
Scaled: 1M+ Records
Ordered: Yes
SARGable Partition Pruning: Exact Half-Open Date Boundary Ranges
Candidate Latency (1M Rows)
0.10 ms
(1.0x faster than golden)
Golden Latency (1M Rows)
0.11 ms
DuckDB in-memory engine
Underlying Data Volume
1,000,000 rows
11.4 MiB across 1 table
Evaluated Model
gemini-3.8-flash-low
Gen Latency: 11.8s
✔ Correctness Verified on 1M+ Records
Candidate SQL output matches ground truth golden query across all multiset rows and numeric tolerances (tol=1e-3). Zero data skew or anti-patterns detected on full dataset scale.
1. Analytical Significance & What It Means
Scenario & Frontier TrapBusiness Scenario & Problem
When filtering analytical partitions for a calendar month, `BETWEEN '2026-01-01' AND '2026-01-31'` leaks into February 1st if timestamps contain hours/minutes, while `strftime('%m', ts) = '01'` disables partition pruning entirely.
⚡ The Frontier Trap (Why LLMs Fail)
Subtle boundary leakage or full table scans caused by non-SARGable WHERE predicates.
Prompt / User Request Given to Model
When filtering analytical partitions for a calendar month, `BETWEEN '2026-01-01' AND '2026-01-31'` leaks into February 1st if timestamps contain hours/minutes, while `strftime('%m', ts) = '01'` disables partition pruning entirely.
Execute the required analytical SQL calculation in DuckDB.
Expected output columns: event_id, created_at.
Results should be ordered as specified.
2. Underlying Tables, Row Counts & Data Volume
1 Tables (1,000,000 rows • 11.4 MiB)Production-scale fixtures loaded into the isolated DuckDB sandbox with at least 1,000,000 records per table:
📊 audit_events
1,000,000 rows
11.4 MiB Data Volume
event_id (INTEGER) created_at (TIMESTAMP)Data Preview (showing sample rows from 1,000,000 total rows):
| # | event_id | created_at |
|---|---|---|
| 1 | 1 | 2026-01-31 23:59:59 |
| 2 | 2 | 2026-02-01 00:00:00 |
| 3 | 3 | 2026-01-15 12:00:00 |
| 4 | 3 | 2026-03-01 09:30:00.000002 |
| 5 | 4 | 2026-03-01 09:30:00.000029 |
| 6 | 5 | 2026-03-01 09:30:00.000053 |
| 7 | 6 | 2026-03-01 09:30:00.000061 |
| 8 | 7 | 2026-03-01 09:30:00.000085 |
| 9 | 8 | 2026-03-01 09:30:00.000102 |
| 10 | 9 | 2026-03-01 09:30:00.000126 |
| 11 | 10 | 2026-03-01 09:30:00.000142 |
| 12 | 11 | 2026-03-01 09:30:00.000161 |
| 13 | 12 | 2026-03-01 09:30:00.000190 |
| 14 | 13 | 2026-03-01 09:30:00.000214 |
| 15 | 14 | 2026-03-01 09:30:00.000230 |
3. Graphical Query Execution Plan & Cost Bottlenecks
Physical Operator Tree (DuckDB 2.0 Profiler)Visual flowchart of the physical execution pipeline. Operators with high relative costs (≥ 20% of query runtime or heavy latency) are visually highlighted:
78.8%
Latency: 0.08 ms
Rows In/Out: 2
Data Vol: 24 B
0.6%
Latency: 0.00 ms
Rows In/Out: 2
Data Vol: 24 B
📁 Projections: ['event_id', 'creat...
20.7%
Latency: 0.02 ms
Rows In/Out: 2
Data Vol: 24 B
📁 memory.main.audit_events
| Operator | Cost % | Latency | Processed Rows | Data Volume | Details / Table | Status |
|---|---|---|---|---|---|---|
| ORDER_BY | 78.8% | 0.08 ms | 2 | 0.00 MB | - | Normal |
| TABLE_SCAN | 20.7% | 0.02 ms | 2 | 0.00 MB | memory.main.audit_events | Normal |
| PROJECTION | 0.6% | 0.00 ms | 2 | 0.00 MB | Projections: ['event_id', 'created_at'] | Normal |
4. Queries Executed (Candidate vs Golden Ground Truth)
Beautified & Syntax HighlightedSELECT event_id,
created_at
FROM audit_events
WHERE created_at >= TIMESTAMP '2026-01-01 00:00:00'
AND created_at < TIMESTAMP '2026-02-01 00:00:00'
ORDER BY created_at;
-- Exact SARGable half-open January 2026 boundary query
SELECT event_id,
created_at
FROM audit_events
WHERE created_at >= TIMESTAMP '2026-01-01 00:00:00'
AND created_at < TIMESTAMP '2026-02-01 00:00:00'
ORDER BY created_at;
CREATE TABLE audit_events (event_id INT, created_at TIMESTAMP);
INSERT INTO audit_events
VALUES (1, '2026-01-31 23:59:59'),
(2, '2026-02-01 00:00:00'),
-- Should NOT be in January
(3, '2026-01-15 12:00:00');
5. Query Results & Expected Ground Truth
Tabular Comparison
Actual Candidate Output
(2 rows × 2 cols)
| # | event_id | created_at |
|---|---|---|
| 1 | 3 | 2026-01-15 12:00:00 |
| 2 | 1 | 2026-01-31 23:59:59 |
Expected Golden Output
(2 rows × 2 cols)
| # | event_id | created_at |
|---|---|---|
| 1 | 3 | 2026-01-15 12:00:00 |
| 2 | 1 | 2026-01-31 23:59:59 |