pfc-archiver-timescaledb

May 20, 2026 · View on GitHub

License: MIT Python PFC-JSONL Version

A standalone daemon that runs alongside TimescaleDB, watches for data older than a configurable retention window, compresses it to PFC format, and writes it to local storage or S3 — automatically.

Runs as a sidecar or cron job — no schema changes, no plugins, no TimescaleDB modifications.


How it works

Every interval_seconds (default: 3600), pfc-archiver-timescaledb runs one archive cycle:

SCAN  ->  EXPORT  ->  COMPRESS  ->  UPLOAD  ->  VERIFY  ->  (optional DROP_CHUNKS)  ->  LOG
  1. SCAN — compute which time partitions in the hypertable are older than retention_days
  2. EXPORT — read rows in partition_days-sized chunks via PostgreSQL wire protocol (port 5432)
  3. COMPRESS — pipe through pfc_jsonl compress.pfc + .pfc.bidx + .pfc.idx
  4. UPLOAD — write to output_dir (local path or s3://bucket/prefix/)
  5. VERIFY — decompress and count rows; must match exported count exactly
  6. DELETE (optional) — call drop_chunks() on the archived range (only if delete_after_archive = true)
  7. LOG — write a JSON run log to log_dir

Supported databases

DatabaseProtocolDefault port
TimescaleDB 2.xPostgreSQL wire (psycopg2)5432

Install

pip install pfc-archiver-timescaledb

# Or from source
git clone https://github.com/ImpossibleForge/pfc-archiver-timescaledb
cd pfc-archiver-timescaledb
pip install -r requirements.txt

The pfc_jsonl binary must be installed:

# Linux x64:
curl -L https://github.com/ImpossibleForge/pfc-jsonl/releases/latest/download/pfc_jsonl-linux-x64 \
     -o /usr/local/bin/pfc_jsonl && chmod +x /usr/local/bin/pfc_jsonl

# macOS Apple Silicon (M1–M4):
curl -L https://github.com/ImpossibleForge/pfc-jsonl/releases/latest/download/pfc_jsonl-macos-arm64 \
     -o /usr/local/bin/pfc_jsonl && chmod +x /usr/local/bin/pfc_jsonl

# macOS Intel:
curl -L https://github.com/ImpossibleForge/pfc-jsonl/releases/latest/download/pfc_jsonl-macos-x64 \
     -o /usr/local/bin/pfc_jsonl && chmod +x /usr/local/bin/pfc_jsonl

# Windows (PowerShell):
Invoke-WebRequest https://github.com/ImpossibleForge/pfc-jsonl/releases/latest/download/pfc_jsonl-windows-x64.exe `
  -OutFile "$env:LOCALAPPDATA\Microsoft\WindowsApps\pfc_jsonl.exe"

Python dependency:

pip install psycopg2-binary

Quick start

# 1. Copy the example config
cp config/timescaledb.toml my_config.toml

# 2. Edit the config
nano my_config.toml

# 3. Dry run (no writes, prints what would be archived)
python pfc_archiver_timescaledb.py --config my_config.toml --dry-run

# 4. Archive once and exit
python pfc_archiver_timescaledb.py --config my_config.toml --once

# 5. Run as a daemon (loops every interval_seconds)
python pfc_archiver_timescaledb.py --config my_config.toml

Configuration

All config is TOML. A complete example is in config/timescaledb.toml.

[db]
db_type   = "timescaledb"
host      = "localhost"
port      = 5432              # Standard PostgreSQL port
user      = "postgres"
password  = "yourpassword"
dbname    = "postgres"
schema    = "public"          # PostgreSQL schema (default: public)
table     = "sensor_data"     # hypertable to archive
ts_column = "time"            # designated timestamp column (timestamptz)

[archive]
retention_days       = 90          # archive data older than this many days
partition_days       = 7           # export this many days per archive file
output_dir           = "./archives/"   # local path or s3://bucket/prefix/
verify               = true        # decompress + count rows after each archive
delete_after_archive = false       # drop_chunks() after successful verify
log_dir              = "./archive_logs/"

[daemon]
interval_seconds = 3600            # how often to run (in daemon mode)

partition_days and chunk alignment

TimescaleDB's drop_chunks() operates at the chunk level. For chunks to be dropped cleanly, partition_days should match your hypertable's chunk_time_interval (default: 7 days).

Check your hypertable's chunk interval:

SELECT * FROM timescaledb_information.dimensions;

If partition_days does not align with a chunk boundary, drop_chunks() will simply drop nothing for that partition — the data stays in the DB but the archive is still written and verified. This is safe: you can adjust partition_days and re-run.


Output format

Each archive cycle produces files named:

<schema>__<table>__<YYYYMMDD>__<YYYYMMDD>.pfc
<schema>__<table>__<YYYYMMDD>__<YYYYMMDD>.pfc.bidx
<schema>__<table>__<YYYYMMDD>__<YYYYMMDD>.pfc.idx

The .pfc file is a PFC-JSONL archive. The .bidx and .idx files are block indexes that let DuckDB decompress only the relevant time window — without reading the whole file.


Log format

Each completed cycle appends a JSON entry to <log_dir>/archive_runs.jsonl:

{
  "ts":        "2026-05-11T18:00:00+00:00",
  "table":     "sensor_data",
  "from_ts":   "2026-01-01T00:00:00+00:00",
  "to_ts":     "2026-01-08T00:00:00+00:00",
  "rows":      312500,
  "jsonl_mb":  55.2,
  "output_mb": 4.9,
  "ratio_pct": 8.9,
  "deleted":   false,
  "status":    "ok"
}

Deleting archived data

delete_after_archive = false by default — pfc-archiver-timescaledb never modifies your TimescaleDB without explicit opt-in.

After confirming your archives are accessible via DuckDB, set delete_after_archive = true and restart. Only partitions that pass the row-count verify step will have their chunks dropped.

How deletion works: Archived chunks are removed using TimescaleDB's native drop_chunks() function — far more efficient than row-level DELETE. It atomically removes entire chunk files.

Requires TimescaleDB 2.x.


Run as a systemd service

[Unit]
Description=pfc-archiver-timescaledb — PFC archive daemon for TimescaleDB
After=network.target

[Service]
Type=simple
User=pfc
WorkingDirectory=/opt/pfc-archiver-timescaledb
ExecStart=/usr/bin/python3 /opt/pfc-archiver-timescaledb/pfc_archiver_timescaledb.py \
          --config /etc/pfc-archiver-timescaledb/timescaledb.toml
Restart=on-failure
RestartSec=60

[Install]
WantedBy=multi-user.target
sudo systemctl enable pfc-archiver-timescaledb
sudo systemctl start pfc-archiver-timescaledb
sudo journalctl -u pfc-archiver-timescaledb -f

Run as a Docker sidecar

# docker-compose.yml
services:
  timescaledb:
    image: timescale/timescaledb:latest-pg16
    environment:
      POSTGRES_PASSWORD: yourpassword
      POSTGRES_DB: mydb
    ports:
      - "5432:5432"

  pfc-archiver-timescaledb:
    image: ghcr.io/impossibleforge/pfc-archiver-timescaledb:latest
    volumes:
      - ./config/timescaledb.toml:/etc/pfc-archiver/config.toml
      - ./archives:/archives
      - ./archive_logs:/logs
    depends_on: [timescaledb]

Querying cold archives

Once archived, your .pfc files are queryable directly from DuckDB:

INSTALL pfc FROM community;
LOAD pfc;
LOAD json;

-- Scan a single archive
SELECT *
FROM read_pfc_jsonl('./archives/public__sensor_data__20260101__20260108.pfc')
LIMIT 100;

-- Time-window query (only decompresses the relevant blocks)
SELECT *
FROM read_pfc_jsonl(
    './archives/public__sensor_data__20260101__20260108.pfc',
    ts_from = epoch(TIMESTAMPTZ '2026-01-03 14:00:00+00'),
    ts_to   = epoch(TIMESTAMPTZ '2026-01-03 15:00:00+00')
);

Part of the PFC Ecosystem

→ View all PFC tools & integrations

Direct integrationWhy
pfc-export-timescaledbSame DB, different mode — exporter is one-shot CLI; archiver runs as a continuous daemon
pfc-archiver-questdbSame concept for QuestDB
pfc-archiver-cratedbSame concept for CrateDB

Disclaimer

pfc-archiver-timescaledb is an independent open-source project and is not affiliated with, endorsed by, or associated with Timescale, Inc. or the TimescaleDB project. TimescaleDB is a trademark of Timescale, Inc.


License

pfc-archiver-timescaledb (this repository) is released under the MIT License — see LICENSE.

The PFC-JSONL binary (pfc_jsonl) is proprietary software — free for personal and open-source use. Commercial use requires a license: info@impossibleforge.com