SQL-FRONTIER Benchmark Deep-Dive / Search & Retrieval / task_060_Q60_ngram_log_signature_search
← Prev: Financial Ledger Running ... ⊞ All 120 Queries Next: Dynamic Query Synonym Exp... →
✔ PASS Search & Retrieval task_060_Q60_ngram_log_signature_search Scaled: 1M+ Records Ordered: Yes

Trigram / N-Gram Token Substring Matching for Technical Error Logs

Candidate Latency (1M Rows)
252.66 ms
(1.1x slower than golden)
Golden Latency (1M Rows)
233.83 ms
DuckDB in-memory engine
Underlying Data Volume
1,000,000 rows
22.9 MiB across 1 table
Evaluated Model
gemini-3.8-flash-low
Gen Latency: 9.1s
✔ 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 Trap
Business Scenario & Problem

In observability platforms (Datadog, Splunk), engineers search stack traces with partial error signatures. Trigram decomposition enables robust partial substring index matching.

⚡ The Frontier Trap (Why LLMs Fail)

Full regex evaluations on raw million-line log tables trigger catastrophic backtracking.

Prompt / User Request Given to Model
In observability platforms (Datadog, Splunk), engineers search stack traces with partial error signatures. Trigram decomposition enables robust partial substring index matching.

Execute the required analytical SQL calculation in DuckDB.
Expected output columns: log_id, error_message, classified_signature.
Results should be ordered as specified.

2. Underlying Tables, Row Counts & Data Volume

1 Tables (1,000,000 rows • 22.9 MiB)

Production-scale fixtures loaded into the isolated DuckDB sandbox with at least 1,000,000 records per table:

📊 incident_logs 1,000,000 rows 22.9 MiB Data Volume
log_id (INTEGER) error_message (VARCHAR)
Data Preview (showing sample rows from 1,000,000 total rows):
# log_id error_message
1 1 java.lang.NullPointerException at com.app.auth.LoginService.verify
2 2 org.postgresql.util.PSQLException: Connection refused
3 3 java.lang.OutOfMemoryError: Java heap space
4 3 java.lang.NullPointerException at com.app.auth.LoginService.verify
5 4 org.postgresql.util.PSQLException: Connection refused
6 5 java.lang.OutOfMemoryError: Java heap space
7 6 java.lang.NullPointerException at com.app.auth.LoginService.verify
8 7 org.postgresql.util.PSQLException: Connection refused
9 8 java.lang.OutOfMemoryError: Java heap space
10 9 java.lang.NullPointerException at com.app.auth.LoginService.verify
11 10 org.postgresql.util.PSQLException: Connection refused
12 11 java.lang.OutOfMemoryError: Java heap space
13 12 java.lang.NullPointerException at com.app.auth.LoginService.verify
14 13 org.postgresql.util.PSQLException: Connection refused
15 14 java.lang.OutOfMemoryError: Java heap space

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:

Pipeline Latency Distribution (Total Plan Time: 172.70 ms) Nodes consuming ≥ 20% of query runtime are highlighted with glowing borders
📐 PROJECTION 3.8%
Latency: 6.50 ms
Rows In/Out: 666,667
Data Vol: 22.89 MB
📁 Projections: ['#0', '#1', '__int...
⏳ ORDER_BY 🔥 41.1% Cost
Latency: 70.95 ms
Rows In/Out: 666,667
Data Vol: 22.89 MB
⚠️ Heavy Execution Bottleneck (41.1% of query runtime)
📐 PROJECTION 4.3%
Latency: 7.49 ms
Rows In/Out: 666,667
Data Vol: 22.89 MB
📁 Projections: ['#0', '#1', '__int...
📐 PROJECTION 13.8%
Latency: 23.89 ms
Rows In/Out: 666,667
Data Vol: 22.89 MB
📁 Projections: ['log_id', 'error_m...
🔍 TABLE_SCAN 🔥 37.0% Cost
Latency: 63.86 ms
Rows In/Out: 666,667
Data Vol: 12.72 MB
📁 memory.main.incident_logs
⚠️ Heavy Execution Bottleneck (37.0% of query runtime)
Operator Cost % Latency Processed Rows Data Volume Details / Table Status
ORDER_BY 41.1% 70.95 ms 666,667 22.89 MB - 🔥 BOTTLENECK
TABLE_SCAN 37.0% 63.86 ms 666,667 12.72 MB memory.main.incident_logs 🔥 BOTTLENECK
PROJECTION 13.8% 23.89 ms 666,667 22.89 MB Projections: ['log_id', 'error_message', 'classi Normal
PROJECTION 4.3% 7.49 ms 666,667 22.89 MB Projections: ['#0', '#1', '__internal_compress_s Normal
PROJECTION 3.8% 6.50 ms 666,667 22.89 MB Projections: ['#0', '#1', '__internal_decompress Normal

4. Queries Executed (Candidate vs Golden Ground Truth)

Beautified & Syntax Highlighted
Candidate SQL Executed by gemini-3.8-flash-low (Runtime on 1M Rows: 252.66 ms) 
SELECT log_id,
       error_message,
       CASE
           WHEN error_message LIKE '%NullPointer%' THEN 'NPE_EXCEPTION'
           WHEN error_message LIKE '%OutOfMemory%' THEN 'OOM_KILL'
           ELSE 'OTHER'
       END AS classified_signature
FROM incident_logs
WHERE error_message LIKE '%NullPointer%'
  OR error_message LIKE '%OutOfMemory%'
ORDER BY log_id;
Golden Reference Ground Truth SQL (Runtime on 1M Rows: 233.83 ms) 
-- Find logs matching 'NullPointer' or 'OutOfMemory' error signatures

SELECT log_id,
       error_message,
       CASE
           WHEN error_message LIKE '%NullPointer%' THEN 'NPE_EXCEPTION'
           WHEN error_message LIKE '%OutOfMemory%' THEN 'OOM_KILL'
           ELSE 'OTHER'
       END AS classified_signature
FROM incident_logs
WHERE error_message LIKE '%NullPointer%'
  OR error_message LIKE '%OutOfMemory%'
ORDER BY log_id;
DuckDB Fixture Setup DDL & Data Population 
CREATE TABLE incident_logs (log_id INT, error_message VARCHAR);


INSERT INTO incident_logs
VALUES (1, 'java.lang.NullPointerException at com.app.auth.LoginService.verify'),
       (2, 'org.postgresql.util.PSQLException: Connection refused'),
       (3, 'java.lang.OutOfMemoryError: Java heap space');

5. Query Results & Expected Ground Truth

Tabular Comparison
Actual Candidate Output (666,667 rows × 3 cols)
# log_id error_message classified_signature
1 1 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
2 3 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
3 3 java.lang.OutOfMemoryError: Java heap space OOM_KILL
4 5 java.lang.OutOfMemoryError: Java heap space OOM_KILL
5 6 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
6 8 java.lang.OutOfMemoryError: Java heap space OOM_KILL
7 9 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
8 11 java.lang.OutOfMemoryError: Java heap space OOM_KILL
9 12 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
10 14 java.lang.OutOfMemoryError: Java heap space OOM_KILL
11 15 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
12 17 java.lang.OutOfMemoryError: Java heap space OOM_KILL
13 18 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
14 20 java.lang.OutOfMemoryError: Java heap space OOM_KILL
15 21 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
16 23 java.lang.OutOfMemoryError: Java heap space OOM_KILL
17 24 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
18 26 java.lang.OutOfMemoryError: Java heap space OOM_KILL
19 27 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
20 29 java.lang.OutOfMemoryError: Java heap space OOM_KILL
21 30 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
22 32 java.lang.OutOfMemoryError: Java heap space OOM_KILL
23 33 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
24 35 java.lang.OutOfMemoryError: Java heap space OOM_KILL
25 36 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
Showing first 25 of 666,667 total rows.
Expected Golden Output (666,667 rows × 3 cols)
# log_id error_message classified_signature
1 1 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
2 3 java.lang.OutOfMemoryError: Java heap space OOM_KILL
3 3 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
4 5 java.lang.OutOfMemoryError: Java heap space OOM_KILL
5 6 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
6 8 java.lang.OutOfMemoryError: Java heap space OOM_KILL
7 9 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
8 11 java.lang.OutOfMemoryError: Java heap space OOM_KILL
9 12 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
10 14 java.lang.OutOfMemoryError: Java heap space OOM_KILL
11 15 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
12 17 java.lang.OutOfMemoryError: Java heap space OOM_KILL
13 18 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
14 20 java.lang.OutOfMemoryError: Java heap space OOM_KILL
15 21 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
16 23 java.lang.OutOfMemoryError: Java heap space OOM_KILL
17 24 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
18 26 java.lang.OutOfMemoryError: Java heap space OOM_KILL
19 27 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
20 29 java.lang.OutOfMemoryError: Java heap space OOM_KILL
21 30 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
22 32 java.lang.OutOfMemoryError: Java heap space OOM_KILL
23 33 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
24 35 java.lang.OutOfMemoryError: Java heap space OOM_KILL
25 36 java.lang.NullPointerException at com.app.auth.LoginService.verify NPE_EXCEPTION
Showing first 25 of 666,667 total rows.
← Prev: Financial Ledger Running ... ⊞ Back to Benchmark Dashboard Next: Dynamic Query Synonym Exp... →