pretty_name: Postgres Incident Diagnosis Benchmark
license: mit
task_categories:
- question-answering
- text-classification
language:
- en
tags:
- postgres
- databases
- observability
- sre
- agents
- benchmark
size_categories:
- n<1K
Postgres Incident Diagnosis Benchmark
Real telemetry from a Postgres 16 database in six states — one healthy, five broken — paired with the ground-truth root cause of each.
The task: given the stats views, say what is wrong. Or say that nothing is.
Why this exists
There is no standard benchmark for database incident diagnosis, so everyone building an AI SRE tool invents their own eval. This is a small, reproducible one with a specific property: on four of the five faults, the obvious answer is wrong.
| id | what a naive answer says | actually correct |
|---|---|---|
missing_index |
add an index | ✅ yes |
plan_regression |
add an index | ❌ run ANALYZE — the schema is fine |
bloat |
the table is just large | ❌ dead tuples, autovacuum is off |
lock_contention |
kill the slow queries | ❌ they're victims; one holder is at fault |
n_plus_1 |
nothing is slow, it's healthy | ❌ 1000 calls at 0.04ms each |
healthy_baseline |
find something anyway | ❌ the answer is "no finding" |
The healthy baseline is included deliberately: a diagnostic tool that invents problems on a working database is worse than one that misses them.
Baselines
Measured, not asserted. python -m evals.baselines reproduces this table.
| approach | score |
|---|---|
always_index — always name something; for a database that's usually an index |
1/6 |
slow_and_big — slowest statement over 10ms and a large table → missing index |
2/6 |
| deterministic detectors (reference implementation) | 6/6 |
slow_and_big is right twice: it names the one genuine index problem, and it
stays quiet on the healthy database. On the other four it returns nothing at
all — once the rig's own statements are excluded (see below), none of those
faults presents as a slow query. Stale statistics, bloat, a lock holder and an
N+1 loop are all invisible to any heuristic that ranks by duration.
Telemetry contains application traffic only
Each scenario clears pg_stat_statements after the fault is created and
before the workload runs, so the injector's own work never reaches the
snapshot. Without that, plan_regression ships with a 9.6-second
INSERT INTO orders … generate_series(1, 300000) and an
ALTER TABLE orders SET (autovacuum_enabled = false) sitting in the statements,
which name the root cause outright and make the scenario trivial.
For the same reason the healthy record is captured after running the same
background traffic as every fault case — an empty statements list would make
len(statements) == 0 a free correct answer.
Labels
expected_detector is one of missing_index, stale_stats, bloat,
lock_contention, n_plus_1, or null for the healthy case. Six records, one
per class, so treat this as a probe rather than a training set.
Fields
| field | description |
|---|---|
id |
scenario identifier |
title |
human-readable name |
expected_root_cause |
ground truth, free text |
expected_detector |
ground-truth label, null when healthy |
category |
indexing, statistics, vacuum, locking, application, none |
fix_target |
whether the fix is in the database, a session, or the application |
naive_answer |
what a pattern-matching tool would say |
naive_answer_correct |
whether that happens to be right |
telemetry.statements |
pg_stat_statements rows |
telemetry.tables |
pg_stat_user_tables + size + autovacuum_enabled |
telemetry.activity |
pg_stat_activity rows |
telemetry.blocking |
waiter → blocker edges from pg_blocking_pids() |
telemetry.settings |
relevant pg_settings values |
Usage
from datasets import load_dataset
ds = load_dataset("yashMaini/postgres-incident-diagnosis", split="train")
correct = 0
for r in ds:
prediction = your_model(r["telemetry"]) # -> a detector name, or None
correct += prediction == r["expected_detector"]
print(f"{correct}/{len(ds)}")
telemetry holds the raw stats rows. A useful prompt is usually
telemetry["statements"] plus telemetry["tables"]; lock_contention is only
solvable from telemetry["blocking"], which is the point of including it.
Reproducing
The telemetry is generated, not hand-written — each row is captured from a live
Postgres after a scripted fault injection, against a deterministic 5.2M row
dataset (setseed(0.42)).
git clone https://github.com/Yashmaini30/pg-reliability-agent
docker compose up -d --build
python -m evals.export_benchmark --out data/
The reference implementation in that repo scores 5/5 detected, 5/5 ranked
first, 0 findings on the healthy baseline using deterministic rules and
EXPLAIN (GENERIC_PLAN) — no model in the detection path.
Project overview, with the findings the detectors produce for each scenario: https://huggingface.co/spaces/yashMaini/pg-reliability-agent (a static page — the clickable sandbox runs locally from the repo above).
Caveats
- Six records. This is a sharp probe, not a broad benchmark.
- Synthetic e-commerce schema, single Postgres 16 instance.
- Absolute timings reflect the machine that generated it; the ratios are the signal, not the milliseconds.