Posts

I wanted to build a RAG pipeline over a pile of PDF manuals, and I was already on Convex. The architecture looked boring on paper: upload the PDF to object storage, extract text in a "use node" action, chunk it, and feed each chunk to the Convex RAG component via rag.add(...). The RAG component would handle embedding and vector storage. Every piece was a known good except one — the text extraction itself. I reached for pdfjs-dist because it’s Mozilla’s own reference implementation. This should have been a one-afternoon job.

Recently I encountered a PostgreSQL error while trying to upsert (insert or update) records with soft deletes. When using partial unique indices, Ecto’s default upsert behavior doesn’t work out of the box, resulting in errors like the following. Here’s how I solved it.

** (Postgrex.Error) ERROR 42P10 (invalid_column_reference) there is no unique or
    exclusion constraint matching the ON CONFLICT specification

Context

When implementing soft deletes (marking records as deleted instead of removing them), you often need unique constraints that only apply to active (non-deleted) records. This is where partial unique indices shine - they allow multiple “deleted” records with the same unique value while ensuring only one active record exists.

Hey there! My plan for this page is to collect bits and pieces I wish I had known when first trying to tackle an issue.