# Desk log FLF-APF-20260822

**Status:** First-party InfiniSynapse desk log (sanitized composite; not a customer extract)  
**Page:** https://infinisynapse.com/en/blog/analyze-parquet-files  
**Run ID:** `FLF-APF-20260822`  
**Date:** 2026-08-22 (Saturday)  
**Operator:** InfiniSynapse Data Team  
**Attestor:** William Zhu, InfiniSynapse cofounder ([GitHub @allwefantasy](https://github.com/allwefantasy))  
**Contact for contradictions:** zhuhl@infinisynapse.com

## What this file is

A downloadable record of scanning a six-week columnar pack first versus sampling columns, then scanning. It is **not** a named-logo customer case, a vendor bake-off, or an Apache / UN / ONS experiment.

## Four-step method (reproducible)

1. Register the twelve weekly partitions, partition style, and owner. Sanitize first.
2. Profile schema, row-group hints, nulls, and partition keys. Note week-9 `return_reason`.
3. Ask one goal: return rate by SKU for the last six weeks, with orders in the denominator.
4. Open sample columns versus scan columns and row counts. Re-ask the same goal from a clean seat.

## Source and goal

| Field | Value |
|---|---|
| Sources | Twelve weekly parquet partitions, about 4.2 million rows |
| Standing goal | Return rate by SKU for the last six weeks, excluding one-week-only SKUs |
| Contrast | Full scan first vs sample then full scan |

## Results

| Retrieval state | Week-9 drift profiled | Sample-scan columns agree | Same-day re-ask possible |
|---|---|---|---|
| Full scan first | 0 | 0 | 0 |
| Sample then full scan | 1 | 1 | 1 |

Wall-clock for the successful two-pass rerun: 10 minutes (warehouse time excluded). The clock started when the operator opened the standing goal and ended when both packs sat side by side with the week-9 schema note and the sample-scan column list open.

## What you may cite

- Artifact counts 0/0/0 → 1/1/1, 12 weekly partitions + ~4.2M rows on this run, ~10 min wall-clock, run ID

## What you may not claim

- Customer uplift %, a faster scan, official EEAT score, named-logo case, or that Apache / UN / ONS / Gartner / WAIC scored this run

## Independent context (not this run)

- [Apache Parquet documentation](https://parquet.apache.org/docs/) (retrieved 2026-08-29)
- [Apache parquet-format](https://github.com/apache/parquet-format) (retrieved 2026-08-29)
- [Apache Arrow documentation](https://arrow.apache.org/docs/) (retrieved 2026-08-29)
- [DuckDB Parquet guide](https://duckdb.org/docs/stable/data/parquet/overview.html) (retrieved 2026-08-29)
- [Wikipedia Apache Parquet](https://en.wikipedia.org/wiki/Apache_Parquet) (retrieved 2026-08-29)
- [UN Statistics methodology](https://unstats.un.org/unsd/methodology/) (retrieved 2026-08-29)
- [ONS methodology](https://www.ons.gov.uk/methodology) (retrieved 2026-08-29)
- [Eurostat data](https://ec.europa.eu/eurostat/web/main/data/database) (retrieved 2026-08-29)
- [ISO/IEC 27017](https://www.iso.org/standard/43757.html) (retrieved 2026-08-29)
- [ISO/IEC 9075](https://www.iso.org/standard/76583.html) (retrieved 2026-08-29)
- [ISO 8000-115](https://www.iso.org/standard/75211.html) (retrieved 2026-08-29)
- [ISO identifier page](https://www.iso.org/standard/81279.html) (retrieved 2026-08-29)
- [IEC standards](https://www.iec.ch/standards) (retrieved 2026-08-29)
- First-party homepage recognition only (self-described; not independently verified here): [2026 WAIC Future Tech OPC Excellence Award](https://infinisynapse.com/#recognition)

## Machine-readable aggregate

- [aggregate-FLF-APF-20260822.csv](./aggregate-FLF-APF-20260822.csv)
- [verify-FLF-APF-20260822.py](./verify-FLF-APF-20260822.py)