# Benchmarking

pgGraph has two benchmark layers:

- internal Rust benchmarks for engine-level changes;
- SQL-facing sandbox benchmarks for realistic PostgreSQL query timing.

This page focuses on the SQL-facing benchmark harness. These benchmarks are a
work in progress and are not intended as a comparison against other graph
databases, PostgreSQL extensions, or graph tools yet. The reported numbers do,
however, represent accurate expected pgGraph query times for the measured
dataset, workload, machine, Docker settings, PostgreSQL version, pgGraph commit,
and cache methodology captured in the report.

<Callout type="warning">
Do not cite the sandbox numbers as a universal performance claim. Treat them as
reproducible local evidence for the exact command, dataset, hardware, and report
JSON produced by the harness.
</Callout>

## Running The Sandbox Benchmark

From the repository root:

```bash
sandbox/run_benchmarks.sh panama
sandbox/run_benchmarks.sh ldbc
sandbox/run_benchmarks.sh all
```

Use `--yes` for non-interactive dataset download approval:

```bash
sandbox/run_benchmarks.sh all --yes
```

The script prints the known download sizes before fetching data:

| Dataset | Source | Compressed | Uncompressed |
|---|---|---:|---:|
| Panama Papers / ICIJ Offshore Leaks | `https://offshoreleaks-data.icij.org/offshoreleaks/csv/full-oldb.LATEST.zip` | 73 MB | 626 MB |
| LDBC SNB Interactive SF1 CsvBasic LongDateFormatter | `https://datasets.ldbcouncil.org/snb-interactive-v1/social_network-sf1-CsvBasic-LongDateFormatter.tar.zst` | 230 MB | unknown |

Generated archives, extracted files, normalized CSVs, virtualenvs, and benchmark
reports are ignored by git.

Clean generated artifacts with:

```bash
sandbox/cleanup.sh --dry-run
sandbox/cleanup.sh
```

## What Is Measured

The SQL-facing benchmark exercises pgGraph through PostgreSQL using the same SQL
functions an application would call. It builds or reuses the repository
PostgreSQL 17 Docker image, downloads real public datasets, normalizes the data
into SQL tables with primary keys and foreign keys, registers those tables with
pgGraph, builds the graph, and runs fixed query workloads.

The report separates:

- dataset download and normalization;
- SQL table load time;
- pgGraph registration;
- `graph.build()` time;
- cold query timing;
- hot query timing;
- machine, Docker, PostgreSQL, git, and dataset metadata.

Each run writes:

```text
sandbox/benchmark/results/<run_id>/report.json
```

Each benchmark result includes:

- dataset and query name;
- plain-language question being answered;
- SQL text and SQL hash;
- phase, iteration, and success state;
- PostgreSQL server execution time from `EXPLAIN (ANALYZE, FORMAT JSON)`;
- host wall time through a Python `psycopg` connection;
- row count;
- result checksum.

## Cache Methodology

Cold and hot runs are deliberately separate.

Cold query timing restarts the Docker container before each cold query. This
clears the PostgreSQL process, PostgreSQL shared buffers, and backend-local
pgGraph state. It does not explicitly drop the host OS page cache or Docker VM
page cache.

Hot query timing runs one unrecorded warmup pass, then measures repeated SQL in
the same persistent PostgreSQL backend. This matters because pgGraph has
backend-local graph state after load.

Cold query timing does not include `graph.build()`. Build time is reported
separately as `prepared.build_seconds`. If you want the full first-use cost,
read both build time and the cold query timings.

## Current Datasets

### Panama Papers

The Panama loader uses the real public ICIJ Offshore Leaks CSV export. It loads
all `nodes-*.csv` files and `relationships.csv`, creates normalized
`panama.nodes` and `panama.edges` tables, enforces endpoint foreign keys, and
registers the graph with dynamic edge labels from the source relationship type.

The normalized table intentionally keeps a compact set of fields needed for
graph search and traversal: label, name, countries, country codes, source ID,
and validity metadata. It is suitable for graph benchmarking, but it is not a
complete relational mirror of every ICIJ source attribute.

The current workload asks:

- Is the Panama graph loaded in this backend, and how large is it?
- Which Panama entities mention Mossack in a registered searchable field?
- What is the two-hop neighborhood around a high-degree Panama node?
- Can pgGraph find the direct path between a high-degree seed and one adjacent target?
- What is the overhead of a one-hop `graph.gql()` scalar projection?
- What is the overhead of returning hydrated GQL node objects?
- What is the overhead of returning coordinate-only GQL node objects?
- How does the same one-hop seed compare through a direct PostgreSQL join and
  the native `graph.traverse()` API?
- How many connected components does the Panama graph have?
- Which nodes are in the first page of the largest connected component?

### LDBC

The LDBC loader uses the official public SNB Interactive SF1 CSV archive. It
models the broader SNB schema, including people, forums, posts, comments,
places, organisations, tags, tag classes, and the main relationships between
them.

The loader prefixes IDs by entity type before loading into PostgreSQL. This
avoids collisions between source IDs from different LDBC tables and makes every
relationship endpoint explicit through foreign keys.

The current workload asks:

- Is the full modeled LDBC graph loaded in this backend, and how large is it?
- Which people have John in their first name?
- Who is directly connected to a high-degree person through the social graph?
- What is the overhead of one-hop `graph.gql()` knows queries with scalar,
  hydrated-node, and coordinate-only outputs?
- How does the same knows seed compare through a direct PostgreSQL join?
- What people, posts, comments, forums, tags, places, and organisations are near a high-degree person within two hops?
- What members, posts, tags, and related nodes are near a busy forum?
- Can pgGraph find the path between a post and one of its tags?
- Can pgGraph connect a tag to its tag class?
- How many connected components does the full modeled LDBC graph have?

## Interpreting Results

The numbers are accurate for the run they came from, but they are not a
cross-tool benchmark. Before publishing or comparing results, include the
generated `report.json`, the exact command, the pgGraph commit, the dirty git
status if any, hardware information, Docker resource limits, and whether the
machine was otherwise idle.

Known limitations:

- host OS and Docker VM page cache are not explicitly dropped;
- Docker CPU and memory limits are not pinned by default;
- p95 from 10 hot iterations is useful signal, but not enough for a polished
  p99 claim;
- `server_execution_ms` measures the checksum wrapper query used for
  verification, not a stripped raw-function-only timing;
- the LDBC workload is broader than the original subset, but it is not the full
  official LDBC Interactive query suite.

We plan to test larger datasets and tighten the methodology over time.
Community feedback is welcome, especially suggestions that make the benchmarks
more accurate, easier to reproduce, or more useful to users evaluating pgGraph.

To submit benchmark results or methodology feedback, email `team@evokoa`.
Include your GitHub username, the
generated `report.json`, the exact command you ran, machine and Docker details,
and any relevant notes about local load, Docker resource limits, storage, or
cache state.

## Internal Rust Benchmarks

The Criterion benchmark target lives in `graph/benches/bfs_bench.rs`.

```bash
cd graph
cargo bench --bench bfs_bench
```

These benchmarks call Rust engine types directly. They do not start PostgreSQL
and do not exercise pgrx, SPI, SQL wrappers, ACL checks, source-row hydration,
artifact loading, or client connection overhead. Use them when changing engine
data structures, traversal behavior, filter-index storage, or overlay traversal.
