dryrun

528 downloads this week 0 stars Extension descriptor

Estimate Parquet scan bytes for SELECT queries without executing them

Compatibility Matrix

This table covers all DuckDB releases that have not reached end-of-life, including LTS releases, and shows the 2 most recent patch releases of each. Older patch releases are not listed, but the extension may be available for them as well.

Installing and Loading

INSTALL dryrun FROM community;
LOAD dryrun;

Example

SELECT *
FROM dryrun(
  'SELECT * FROM ''https://dryrun-data.dahl.dev/gaia-5m.parquet'''
);

About dryrun

Dryrun adds a table function for estimating Parquet scan bytes before running a query.

It parses a read-only SELECT statement, finds explicit Parquet scan sources, determines required columns, uses Parquet metadata for compressed column-chunk sizes, and applies simple row-group pruning from min/max statistics when possible.

The result reports estimated data bytes, estimated Parquet metadata bytes, files, row groups used versus total row groups, confidence, and notes (if any).

Added Functions

Overloaded Functions

This extension does not add any function overloads.

Added Types

This extension does not add any types.

Added Settings