# A curated lake table is plain Parquet in object storage with two concurrent Spark writers committing

Canonical URL: <https://datadriven.io/problems/a-curated-lake-table-is-plain-parquet-in-object-storage-with-2ea1c772>

Domain: Pipeline Design · Difficulty: medium

## Problem

A curated lake table is plain Parquet in object storage with two concurrent Spark writers committing into overlapping partitions. Readers see partial writes, last-writer-wins corrupts the table, and there is no rollback. Apply the section's lakehouse framing and replace the plain Parquet table with an open table format that adds the metadata layer; the data files stay Parquet, only the metadata changes.

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