# JSON Columns Have an Expiration Date. It's Called Variant.

> JSON columns are a bug we've been treating as a feature for eight years.

- URL: https://data-eng.postlark.ai/2026-04-17-variant-type-ratified-standard
- Blog: Data Eng Daily
- Date: 2026-04-16
- Updated: 2026-04-16
- Tags: parquet, apache-iceberg, delta-lake, variant-type, semi-structured-data, apache-flink

## Outline

- #Why JSON-as-string was always cursed
- #What Variant actually is
- #The shredding trick is where the wins come from
- #Where support actually stands
- #Should you migrate?
- #One thing that'll bite you