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Output node

Parquet File

Write the incoming rows to a columnar Parquet file.

Category
Output

What it does

Writes the incoming rows to a compressed, columnar Parquet file that you download from the run afterwards. Parquet stores the schema alongside the data, so every column comes back with the type it left with: nothing is re-guessed and no leading zeros are lost. Pick a compression codec to trade file size against write speed.

Inputs and outputs

InputsOne.
OutputsNone. This node ends a pipeline.

When to use it

  • Store a large result efficiently
  • Hand off to a data lake, a warehouse loader, or a later pipeline
  • Keep exact column types across runs, where CSV would lose them

Examples

Default

Compression: snappy

Fast to write and well compressed: the right answer unless you know otherwise.

Smaller file

Compression: gzip

Noticeably smaller, noticeably slower. Worth it when you're paying to move the file.

Uncompressed

Compression: none

Only for a reader that can't decompress. Rare.

Between pipelines

Parquet File  →  a later run's Parquet Files input

Types survive the round trip exactly, which CSV can't promise.

Tips

  • Find the file on the run's detail page once the run finishes.
  • A Test run leaves you nothing to download; press Run for a real file.
  • A run producing ZERO rows writes no file at all: Parquet needs a schema to write its footer and there is nothing to take one from, so an empty result is an absent file rather than an empty one.
  • Snappy is the best default. gzip only pays off when you're moving the file over a slow link or paying for the storage.
  • This is the format to use between Trinium pipelines: it's the only one here that carries types.