Output Formats

Supported output formats and their use cases.

Output Formats

Seedling supports multiple output formats for different use cases.

SQL Dump

Default format. Produces INSERT INTO ... statements.

seedling generate --count 10000 --output seed.sql

Use cases: CI pipelines, staging refresh, database seeding.

Direct Database Insert

Writes directly to a live database with batched INSERTs.

seedling generate --count 500000 --db postgres://localhost:5432/staging

Use cases: One-shot staging population, integration tests.

Postgres COPY Protocol

Maximum throughput. Uses pgx COPY protocol for row streaming.

seedling generate --count 1000000 --db postgres://localhost:5432/staging --copy

Use cases: Large-scale data generation where speed matters.

CSV

One file per table.

seedling generate --count 10000 --output data/ --format csv

Use cases: Data analysis, spreadsheets, external tool import.

JSON Lines

One JSON object per row, streaming per table.

seedling generate --count 10000 --output data/ --format jsonl

Use cases: Event streams, NoSQL databases, log simulation.

Parquet

Tabular columnar output.

seedling generate --count 10000 --output data/ --format parquet

Note: Parquet support is currently a TSV placeholder. Full Parquet implementation is pending.

Format Summary

Format	Flag	Use Case
SQL dump	--output seed.sql	CI, staging refresh
Direct DB	--db postgres://...	One-shot population
COPY	--db ... --copy	Max throughput
CSV	--format csv	Analysis, spreadsheets
JSON Lines	--format jsonl	Event streams
Parquet	--format parquet	Data lake (TSV placeholder)