✔ PASS
Temporal & Time-Series
task_008_Q08_hopping_sliding_time_buckets
Scaled: 1M+ Records
Ordered: Yes
Hopping / Overlapping Window Aggregations via time_bucket
Candidate Latency (1M Rows)
0.56 ms
(1.1x faster than golden)
Golden Latency (1M Rows)
0.59 ms
DuckDB in-memory engine
Underlying Data Volume
1,000,000 rows
34.3 MiB across 1 table
Evaluated Model
gemini-3.8-flash-low
Gen Latency: 16.0s
✔ 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
Real-time surveillance monitors rolling 15-minute average latency stepped forward every 5 minutes (a hopping window).
⚡ The Frontier Trap (Why LLMs Fail)
Standard GROUP BY time_bucket only produces non-overlapping tumbling windows, missing cross-boundary bursts.
Prompt / User Request Given to Model
Real-time surveillance monitors rolling 15-minute average latency stepped forward every 5 minutes (a hopping window). Execute the required analytical SQL calculation in DuckDB. Expected output columns: window_start, window_end, server_id, sample_count, avg_cpu, peak_cpu. Results should be ordered as specified.
2. Underlying Tables, Row Counts & Data Volume
1 Tables (1,000,000 rows • 34.3 MiB)Production-scale fixtures loaded into the isolated DuckDB sandbox with at least 1,000,000 records per table:
📊 server_metrics
1,000,000 rows
34.3 MiB Data Volume
server_id (VARCHAR) metric_time (TIMESTAMP) cpu_utilization (DOUBLE)Data Preview (showing sample rows from 1,000,000 total rows):
| # | server_id | metric_time | cpu_utilization |
|---|---|---|---|
| 1 | web-01 | 2026-03-01 10:02:00 | 45 |
| 2 | web-01 | 2026-03-01 10:07:00 | 78 |
| 3 | web-01 | 2026-03-01 10:12:00 | 92 |
| 4 | web-01 | 2026-03-01 10:17:00 | 60 |
| 5 | node-cluster-1 | 2026-03-01 09:30:00.000011 | 97.56 |
| 6 | node-cluster-2 | 2026-03-01 09:30:00.000020 | 69.34 |
| 7 | node-cluster-3 | 2026-03-01 09:30:00.000041 | 66.5 |
| 8 | node-cluster-4 | 2026-03-01 09:30:00.000063 | 60.83 |
| 9 | node-cluster-5 | 2026-03-01 09:30:00.000088 | 47.52 |
| 10 | node-cluster-6 | 2026-03-01 09:30:00.000104 | 79.26 |
| 11 | node-cluster-7 | 2026-03-01 09:30:00.000130 | 95 |
| 12 | node-cluster-8 | 2026-03-01 09:30:00.000153 | 101.11 |
| 13 | node-cluster-9 | 2026-03-01 09:30:00.000162 | 64.81 |
| 14 | node-cluster-10 | 2026-03-01 09:30:00.000185 | 55.34 |
| 15 | node-cluster-11 | 2026-03-01 09:30:00.000208 | 48.89 |
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:
0.2%
Latency: 0.00 ms
Rows In/Out: 4
Data Vol: 224 B
📁 Projections: ['#0', '#1', '__int...
23.4%
Latency: 0.13 ms
Rows In/Out: 4
Data Vol: 224 B
0.6%
Latency: 0.00 ms
Rows In/Out: 4
Data Vol: 224 B
📁 Projections: ['#0', '#1', '__int...
1.8%
Latency: 0.01 ms
Rows In/Out: 4
Data Vol: 224 B
📁 Projections: ['window_start', 'w...
1.3%
Latency: 0.01 ms
Rows In/Out: 4
Data Vol: 192 B
📁 Projections: ['#0', '#1', '#2', ...
0.9%
Latency: 0.01 ms
Rows In/Out: 4
Data Vol: 224 B
📁 Projections: ['#0', '__internal_...
50.7%
Latency: 0.28 ms
Rows In/Out: 4
Data Vol: 192 B
0.0%
Latency: 0.00 ms
Rows In/Out: 9
Data Vol: 360 B
📁 Projections: ['window_start', 's...
0.4%
Latency: 0.00 ms
Rows In/Out: 9
Data Vol: 288 B
📁 Projections: ['__internal_compre...
15.9%
Latency: 0.09 ms
Rows In/Out: 9
Data Vol: 360 B
3.7%
Latency: 0.02 ms
Rows In/Out: 4
Data Vol: 128 B
📁 memory.main.server_metrics
0.1%
Latency: 0.00 ms
Rows In/Out: 4
Data Vol: 32 B
📁 Projections: window_start
1.0%
Latency: 0.01 ms
Rows In/Out: 4
Data Vol: 48 B
0.1%
Latency: 0.00 ms
Rows In/Out: 1
Data Vol: 4 B
| Operator | Cost % | Latency | Processed Rows | Data Volume | Details / Table | Status |
|---|---|---|---|---|---|---|
| HASH_GROUP_BY | 50.7% | 0.28 ms | 4 | 0.00 MB | - | Normal |
| ORDER_BY | 23.4% | 0.13 ms | 4 | 0.00 MB | - | Normal |
| NESTED_LOOP_JOIN | 15.9% | 0.09 ms | 9 | 0.00 MB | - | Normal |
| TABLE_SCAN | 3.7% | 0.02 ms | 4 | 0.00 MB | memory.main.server_metrics | Normal |
| PROJECTION | 1.8% | 0.01 ms | 4 | 0.00 MB | Projections: ['window_start', 'window_end', 'ser | Normal |
| PROJECTION | 1.3% | 0.01 ms | 4 | 0.00 MB | Projections: ['#0', '#1', '#2', '"/"(#3, CAST(#5 | Normal |
| UNNEST | 1.0% | 0.01 ms | 4 | 0.00 MB | - | Normal |
| PROJECTION | 0.9% | 0.01 ms | 4 | 0.00 MB | Projections: ['#0', '__internal_decompress_strin | Normal |
| PROJECTION | 0.6% | 0.00 ms | 4 | 0.00 MB | Projections: ['#0', '#1', '__internal_compress_s | Normal |
| PROJECTION | 0.4% | 0.00 ms | 9 | 0.00 MB | Projections: ['__internal_compress_string_uhugei | Normal |
| PROJECTION | 0.2% | 0.00 ms | 4 | 0.00 MB | Projections: ['#0', '#1', '__internal_decompress | Normal |
| DUMMY_SCAN | 0.1% | 0.00 ms | 1 | 0.00 MB | - | Normal |
| PROJECTION | 0.1% | 0.00 ms | 4 | 0.00 MB | Projections: window_start | Normal |
| PROJECTION | 0.0% | 0.00 ms | 9 | 0.00 MB | Projections: ['window_start', 'server_id', 'cpu_ | Normal |
4. Queries Executed (Candidate vs Golden Ground Truth)
Beautified & Syntax HighlightedWITH window_steps AS
(SELECT unnest(generate_series(TIMESTAMP '2026-03-01 10:00:00', TIMESTAMP '2026-03-01 10:15:00', INTERVAL '5 minutes')) AS window_start)
SELECT w.window_start,
w.window_start + INTERVAL '15 minutes' AS window_end,
m.server_id,
count(m.cpu_utilization) AS sample_count,
round(avg(m.cpu_utilization), 2) AS avg_cpu,
max(m.cpu_utilization) AS peak_cpu
FROM window_steps w
JOIN server_metrics m ON m.metric_time >= w.window_start
AND m.metric_time < w.window_start + INTERVAL '15 minutes'
GROUP BY w.window_start,
m.server_id
ORDER BY w.window_start;
-- Generate 15-minute sliding windows stepped every 5 minutes (hopping window)
WITH window_steps AS
(SELECT unnest(generate_series(TIMESTAMP '2026-03-01 10:00:00', TIMESTAMP '2026-03-01 10:15:00', INTERVAL '5 minutes')) AS window_start)
SELECT w.window_start,
w.window_start + INTERVAL '15 minutes' AS window_end,
m.server_id,
count(m.cpu_utilization) AS sample_count,
round(avg(m.cpu_utilization), 2) AS avg_cpu,
max(m.cpu_utilization) AS peak_cpu
FROM window_steps w
JOIN server_metrics m ON m.metric_time >= w.window_start
AND m.metric_time < w.window_start + INTERVAL '15 minutes'
GROUP BY w.window_start,
m.server_id
ORDER BY w.window_start;
CREATE TABLE server_metrics (server_id VARCHAR, metric_time TIMESTAMP, cpu_utilization DOUBLE);
INSERT INTO server_metrics
VALUES ('web-01', '2026-03-01 10:02:00', 45.0),
('web-01', '2026-03-01 10:07:00', 78.0),
('web-01', '2026-03-01 10:12:00', 92.0),
('web-01', '2026-03-01 10:17:00', 60.0);
5. Query Results & Expected Ground Truth
Tabular Comparison
Actual Candidate Output
(4 rows × 6 cols)
| # | window_start | window_end | server_id | sample_count | avg_cpu | peak_cpu |
|---|---|---|---|---|---|---|
| 1 | 2026-03-01 10:00:00 | 2026-03-01 10:15:00 | web-01 | 3 | 71.67 | 92 |
| 2 | 2026-03-01 10:05:00 | 2026-03-01 10:20:00 | web-01 | 3 | 76.67 | 92 |
| 3 | 2026-03-01 10:10:00 | 2026-03-01 10:25:00 | web-01 | 2 | 76 | 92 |
| 4 | 2026-03-01 10:15:00 | 2026-03-01 10:30:00 | web-01 | 1 | 60 | 60 |
Expected Golden Output
(4 rows × 6 cols)
| # | window_start | window_end | server_id | sample_count | avg_cpu | peak_cpu |
|---|---|---|---|---|---|---|
| 1 | 2026-03-01 10:00:00 | 2026-03-01 10:15:00 | web-01 | 3 | 71.67 | 92 |
| 2 | 2026-03-01 10:05:00 | 2026-03-01 10:20:00 | web-01 | 3 | 76.67 | 92 |
| 3 | 2026-03-01 10:10:00 | 2026-03-01 10:25:00 | web-01 | 2 | 76 | 92 |
| 4 | 2026-03-01 10:15:00 | 2026-03-01 10:30:00 | web-01 | 1 | 60 | 60 |