JSON
Extracting Properties Into Typed Columns Nightly From JSON
A nightly job that turns jsonb event properties into a typed facts table in PostgreSQL: safe casts, a watermark, idempotent inserts and a 47x speedup.
7 min read
Library
Everything you need to level up your coding skills.
JSON
Designing JSON Event Properties for Analysis From Day One
Four designs for the same 500,000 purchase events compared on size and query time: verbose nesting, short flat keys, hybrid columns and key/value arrays.
6 min read
JSON
Parsing a Package Registry Metadata File Where Keys Are Data
Read a package metadata document where version numbers are keys: json_each, DuckDB MAP inference, semver sorting, dist-tags versus max, and the time map.
7 min read
JSON
Converting YAML to JSON for Tools That Need It Safely
Convert YAML to JSON with PyYAML and ruamel.yaml, and handle dates, yes and no, octal numbers, non-string keys, anchors, multiple documents and floats.
8 min read
JSON
Converting JSON to YAML on the Command Line Safely
Convert JSON to YAML with yq, Python's yq and a PyYAML one-liner, and see which strings get corrupted by YAML 1.1 readers: NO, yes, 12:30, 0123 and 1e3.
7 min read
CSV
Choosing Column Names Users Recognize in CSV Imports
Name CSV columns in the user's words, keep a stable internal key and accept aliases on import. A mapping function tested on three realistic headers.
7 min read
CSV
Background Jobs for Large CSV Exports That Do Not Time Out
Move big CSV exports into a job: chunk by key, write to storage, send an expiring link, track progress and clean up. Keyset chunks beat OFFSET.
8 min read
CSV
Streaming a CSV Export From a Web App Without Memory Spikes
Stream a CSV download instead of building it in memory: one million rows took 336 MB as an array and 2 MB streamed. Headers, buffering and limits.
7 min read
CSV
Reporting Row Level Errors Back to the User of a CSV Import
Report CSV import errors users can act on: line, column, value and rule, all problems per row, and a file of rejected rows to fix and re-upload.
8 min read
CSV
Previewing a CSV Upload Before Committing Any Changes
Preview a CSV import safely: inspect the file, then run the real import in a transaction that rolls back to count creates, updates and errors.
7 min read
CSV
Designing a CSV Import Screen Users Can Succeed With
What a CSV import screen needs so users succeed: a template, clear limits, column mapping, a preview, plain-language errors and a count before commit.
7 min read
CSVGuide
CSV Import and Export Features in Applications Done Right
Build CSV import and export into an application: staged imports with dry runs, streamed and background exports, column names, round trips and safety.
19 min read
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