---
license: apache-2.0
task_categories:
  - text-classification
  - feature-extraction
language:
  - en
  - de
  - it
  - fr
  - es
  - uk
  - cs
  - nl
  - ja
  - el
  - pt
  - sk
  - sl
  - nb
  - fi
  - ro
  - sr
  - hr
  - lv
  - pl
  - ky
  - he
  - da
  - sv
  - id
tags:
  - open-data
  - ckan
  - dcat
  - socrata
  - opendatasoft
  - arcgis
  - stac
  - csw
  - sdmx
  - government
  - metadata
  - geospatial
pretty_name: Ceres Open Data Index
size_categories:
  - 1M<n<10M
---

# Ceres Open Data Index

A curated index of **2,745,021 open dataset records** from **567 portal exports** across 40+ countries and international sources, with cross-portal duplicates flagged. The snapshot includes normalized dataset metadata, resource links when supplied by the source, and a reproducible manifest with file checksums.

## Dataset description

This dataset was harvested by [Ceres](https://github.com/AndreaBozzo/Ceres), a harvest-first open-data toolkit. It covers ten source families: CKAN, DCAT-AP (udata REST), SPARQL-backed DCAT, Project Open Data (`data.json`), Socrata, OpenDataSoft, ArcGIS Hub, OGC Records/CSW, collection-level STAC, and SDMX. Noise is filtered during export; likely cross-portal duplicates are flagged but retained.

### What's included

- Titles, descriptions, URLs, tags, organizations, licenses, and source provenance
- Resource-level names, formats, media types, URLs, and schema field counts when available
- A heuristic cross-portal duplicate signal (`is_duplicate`)
- Per-portal Parquet subsets for targeted analysis
- A versioned manifest, quality report, and snapshot-to-snapshot changelog

### What's not included

- The data files themselves (CSVs, shapefiles, and similar assets)
- Embedding vectors, which are model-specific
- A canonical entity-resolution result; `is_duplicate` is only a title-based heuristic

> Resource links are present for 1,997,796 rows (72.8%); 96,395 rows (3.5%) include at least one resource schema. Coverage varies substantially by source API.

## Dataset structure

### Schema

| Column | Type | Nullable | Description |
|--------|------|----------|-------------|
| `original_id` | string | no | Record identifier from the source portal |
| `source_portal` | string | no | Canonical source portal URL |
| `portal_name` | string | no | Stable export name for the portal |
| `url` | string | no | Dataset or catalog-record landing page |
| `title` | string | no | Record title |
| `description` | string | yes | Record description |
| `record_kind` | string | no | Normalized kind of catalog record |
| `tags` | string | yes | Comma-separated source tags |
| `organization` | string | yes | Publishing organization |
| `license` | string | yes | License title or identifier |
| `metadata_created` | string | yes | Source creation date (ISO 8601) |
| `metadata_modified` | string | yes | Source modification date (ISO 8601) |
| `first_seen_at` | string | no | When Ceres first indexed the record (RFC 3339) |
| `language` | string | yes | Source or portal language label |
| `is_duplicate` | boolean | no | Exact case-insensitive title also occurs on another canonical portal |
| `resources` | list of structs | no | Resource entries: `name`, `format`, `media_type`, `url`, and `field_count` |

### Files

- `all.parquet` — complete dataset (2,745,021 rows)
- `data/<portal>.parquet` — 567 portal subsets; rows repeat those in `all.parquet`
- `identity.parquet` — record keys and content hashes used for snapshot diffs
- `metadata.json` — snapshot manifest, Ceres provenance, curation counts, aliases, and SHA-256 checksums
- `reports.json` / `report.md` — coverage and field-completeness report
- `changelog.json` / `changelog.md` — added, changed, removed, and unchanged counts versus v5

Manifest paths are unique. This release contains 569 Parquet files in total (`all.parquet`, `identity.parquet`, and 567 portal subsets), and every file's size, checksum, and row count was verified before publication.

### Largest portal exports

Top 48 by exported row count (of 567 total):

| Portal export | Source | Family/profile | Rows |
|---|---|---|---:|
| eu-open-data | data.europa.eu | DCAT / SPARQL | 712,481 |
| catalog-data-gov | catalog.data.gov | CKAN | 399,597 |
| queensland | data.qld.gov.au | CKAN | 181,970 |
| www-govdata-de | govdata.de | CKAN | 158,177 |
| data-gov-au | data.gov.au | CKAN | 139,729 |
| ods-hub | data.opendatasoft.com | OpenDataSoft | 91,100 |
| dati-gov-it | dati.gov.it | CKAN | 65,077 |
| ckan-publishing-service-gov-uk | ckan.publishing.service.gov.uk | CKAN | 57,244 |
| data-gov-uk | data.gov.uk | CKAN | 57,060 |
| spain-datos | datos.gob.es | DCAT / SPARQL | 49,930 |
| open-canada-ca | open.canada.ca | CKAN | 47,437 |
| data-gouv-fr | data.gouv.fr | DCAT / udata | 43,186 |
| data-gov-ua | data.gov.ua | CKAN | 36,960 |
| banque-de-france | webstat.banque-france.fr | OpenDataSoft | 35,837 |
| czech-republic | data.gov.cz | DCAT / SPARQL | 32,660 |
| data-humdata-org | data.humdata.org | CKAN | 28,039 |
| geodati-gov-it | geodati.gov.it | geospatial catalog | 23,578 |
| healthdata-gov | healthdata.gov | Project Open Data | 22,417 |
| greece | data.gov.gr | CKAN | 21,900 |
| data-gov-ie | data.gov.ie | CKAN | 21,267 |
| california-natural-resources | data.cnra.ca.gov | CKAN | 21,114 |
| data-overheid-nl | data.overheid.nl | CKAN | 20,796 |
| dados-gov-pt | dados.gov.pt | DCAT / udata | 20,792 |
| spain-idee-csw | idee.es | OGC Records/CSW | 18,690 |
| pndb | pndb.opendatasoft.com | OpenDataSoft | 17,710 |
| netl-edx | edx.netl.doe.gov | CKAN | 17,186 |
| switzerland | opendata.swiss | CKAN | 15,863 |
| www-geocatalogue-fr | geocatalogue.fr | geospatial catalog | 14,960 |
| nrw | open.nrw.de | CKAN | 14,910 |
| japan | data.e-gov.go.jp | CKAN | 12,276 |
| dati-toscana-it | dati.toscana.it | CKAN | 12,214 |
| slovakia | data.slovensko.sk | DCAT / SPARQL | 11,748 |
| metadane-podgik-pl | metadane.podgik.pl | geospatial catalog | 11,264 |
| statistics-lithuania-sdmx | osp-rs.stat.gov.lt | SDMX | 9,500 |
| www-geonorge-no | geonorge.no | geospatial catalog | 9,190 |
| podatki-gov-si | podatki.gov.si | CKAN | 8,956 |
| norway | data.norge.no | DCAT / SPARQL | 8,669 |
| catalog-data-metro-tokyo-lg-jp | metro.tokyo.lg.jp | CKAN | 8,483 |
| nationaalgeoregister-nl | nationaalgeoregister.nl | geospatial catalog | 8,140 |
| www-datos-gov-co | datos.gov.co | Socrata | 7,773 |
| emodnet-csw | emodnet.ec.europa.eu | OGC Records/CSW | 7,104 |
| www-datosabiertos-gob-pa | datosabiertos.gob.pa | CKAN | 5,607 |
| discover-data-vic-gov-au | discover.data.vic.gov.au | CKAN | 5,578 |
| dati-regione-marche-it | dati.regione.marche.it | CKAN | 5,450 |
| data-gov-ro | data.gov.ro | CKAN | 5,018 |
| data-virginia-gov | data.virginia.gov | Project Open Data | 4,825 |
| data-ca-gov | data.ca.gov | Project Open Data | 4,506 |
| cioos-pacific | catalogue.cioos.ca | CKAN | 3,484 |

The full portal breakdown and exact source URLs are recorded in `metadata.json` and `reports.json`. Alias feeds such as a portal's root API and its `/data.json` endpoint can share a canonical export name without being treated as independent sources.

### Coverage and quality

Exporter classification by source type: **unmapped/legacy config** 1,318,679 · **DCAT** 835,846 · **CKAN** 327,737 · **OpenDataSoft** 177,191 · **OGC Records/CSW** 27,264 · **ArcGIS** 24,302 · **SDMX** 15,160 · **Socrata** 11,833 · **STAC** 7,009. The `unknown` classification reflects missing type annotations in the export configuration, not unknown provenance; source URLs remain present.

DCAT profiles account for **817,318 SPARQL**, **12,058 static JSON**, and **3,477 udata REST** records. Field completeness is: description **100.0%** · resources **72.8%** · modification date **52.4%** · organization **51.2%** · tags **45.3%** · license **31.8%** · resource schema **3.5%**.

Language labels are source/portal metadata rather than per-row language detection. The largest labels are English (`en`) 1,182,023; unknown 1,161,936; `eng` 87,963; Spanish 76,992; French 75,086; Ukrainian 36,301; Czech 32,879; Greek 21,900; Japanese 14,224; Slovak 11,748; and Norwegian 8,669.

### Loading the dataset

```python
import pandas as pd

df = pd.read_parquet("all.parquet")
df_us = pd.read_parquet("data/catalog-data-gov.parquet")
likely_unique = df[~df["is_duplicate"]]
```

Or with DuckDB:

```sql
SELECT source_portal, count(*) AS records
FROM read_parquet('all.parquet')
GROUP BY source_portal
ORDER BY records DESC;
```

## Dataset creation

### Harvesting methodology

Ceres harvests each portal through its native API with a streaming, incremental pipeline:

1. CKAN portals use paged `package_search` requests with adaptive page sizing and retry behavior.
2. DCAT udata catalogs use paged JSON-LD; Project Open Data catalogs consume `data.json` documents.
3. SPARQL-backed DCAT catalogs use stable keyset pagination, bounded distribution-property queries, and URI-level deduplication.
4. Socrata uses the Discovery API; OpenDataSoft uses the Explore API with a keyset cursor beyond its 10,000-row window.
5. ArcGIS Hub, OGC Records/CSW, collection-level STAC, and SDMX clients preserve family-specific source metadata.
6. `ceres export --format parquet` streams PostgreSQL records, filters noise, flattens metadata, flags cross-portal title matches, and writes compressed Parquet plus checksummed reports.

The data.europa.eu refresh was intentionally stopped after resource enrichment reached approximately half the exported portal rows so this snapshot would not delay Ceres 0.7.0. The export contains 712,481 data.europa.eu records, of which 366,307 (51.4%) include resource metadata. Completing the remaining enrichment is tracked in [Ceres issue #254](https://github.com/AndreaBozzo/Ceres/issues/254) for the next release.

### Curation

- **Noise filtering:** 81,766 rows removed (short/noise titles and empty descriptions)
- **Duplicate flagging:** 1,354,529 rows marked; records are retained and no canonical entity resolution is claimed
- **Alias normalization:** known mirror or alternate endpoints can share a canonical portal identity
- **Metadata flattening:** nested source fields and resource metadata are normalized into the published schema

The duplicate method and version are recorded under `duplicate_detection` in `metadata.json`.

### Update and provenance

Snapshot **`ceres-20260819-884e6da7b4b0`** was generated on **2026-08-19** by Ceres **0.7.0** at commit **`2583fcf`**. Relative to `ceres-20260715-ed0c345e8663`, it has **183,625 added**, **172,349 changed**, **2,613 removed**, and **2,389,047 unchanged** records. See `changelog.md` for the per-portal breakdown.

## Considerations

### Known biases and limitations

- Large aggregators dominate the index: data.europa.eu contributes 26.0% and catalog.data.gov 14.6% of rows.
- The partial data.europa.eu refresh means resource coverage is materially better than v5 but not complete.
- 49.3% of rows are flagged as possible cross-portal title duplicates, especially because aggregators re-list member-portal records.
- Metadata quality, vocabulary, timestamps, and license conventions vary by source; only 31.8% of rows have a non-empty license.
- SPARQL, STAC, OGC, and SDMX records may have fewer normalized fields than CKAN or Socrata records.
- Exporter `language` and source-type annotations are incomplete for legacy configurations, but original source URLs and metadata are retained.

### Ethical considerations

This dataset contains public catalog metadata from government and institutional portals. It does not intentionally contain the underlying data files. Source licenses vary; consumers must follow the license and terms attached to each source record.

## Additional information

### License

This aggregate dataset and its tooling are released under [Apache 2.0](https://www.apache.org/licenses/LICENSE-2.0). Underlying source metadata may carry separate open-data licenses recorded per row where available.

### Citation

```bibtex
@misc{ceres-open-data-index-2026,
  title={Ceres Open Data Index},
  author={Andrea Bozzo},
  year={2026},
  url={https://github.com/AndreaBozzo/Ceres},
  note={2,745,021 records from 567 portal exports, snapshot 2026-08-19}
}
```

### Links

- [Ceres on GitHub](https://github.com/AndreaBozzo/Ceres)
- [Ceres documentation](https://learnceres.pages.dev/)