Data Connectors

Upload files, or connect SQL/NoSQL databases, cloud warehouses, REST/GraphQL APIs, and cloud storage.

6 min readOpen in app

Video walkthrough coming soon

/public/media/data-connectors-walkthrough.mp4

Uploading your first dataset — 90 seconds.

Supported file uploads

Tabular: CSV, TSV, Excel (.xlsx/.xls), Parquet, JSON
Statistical: SPSS (.sav), Stata (.dta), SAS (.sas7bdat)
Images: ZIP / TAR archives up to 10 GB (auto-extracted and stream-loaded)

Live connectors (20 sources)

Databases: PostgreSQL, MySQL, SQL Server (MSSQL), SQLite, MongoDB, Redis
Warehouses & search: Snowflake, BigQuery, Elasticsearch
APIs & sheets: REST API, GraphQL, Google Sheets, URL import
File transfer & cloud storage: FTP, SFTP, Amazon S3
Survey & research platforms: REDCap, Qualtrics, ODK Central, KoboToolbox

Survey-platform data

REDCap, Qualtrics, ODK Central and KoboToolbox are all direct connectors — they fetch the data dictionary / survey / form definition and apply value labels (coded answers become their choice text). Nexmetry can also generate a KoboToolbox/ODK data-collection form (XLSForm) from the Indicator Library.

Uploading a file

1
Open Data Connectors
Sidebar → Data Hub → Data Connectors.
2
Drop or select the file
Files stream directly to disk (no OOM on large CSVs). The Data Connectors upload cap is 500 MB — for files up to 10 GB use the resumable chunked uploader on the Upload tab in Projects & Data.
3
Review auto-detected schema
Types, units, and missingness are detected automatically. Override any column before finalizing.
4
Validate and save
Nexmetry runs quality checks (duplicate IDs, impossible values, encoding issues) and stores the dataset with a content hash for reproducibility.

Large uploads

Resumable uploads are available on the Projects & Data Upload tab, which uploads in 5 MB chunks and resumes after a network drop. A full page reload loses the file handle, so resume only works within the same session.

Keyboard shortcuts

Preparing datasets