Performance — Keep Loads Fast

Rule

Treat every list, every read, and every page load as a latency budget. Two things dominate it: how much data crosses the wire, and how many round-trips and table scans it takes. On a hosted/serverless SQL backend each query is a network round-trip, and an unindexed filter scans the whole — often shared and growing — table. So default to projected columns, indexed hot-path queries, and parallel/batched fetches. These rules are provider-agnostic: they hold on SQLite, Postgres, or any managed SQL backend.

This skill is about the data and load path. See the storing-data skill for the schema and migration mechanics it references, and the real-time-sync skill for how updates already reach the UI without polling.

1. Project columns — never SELECT * on a list

A list/index query should select only the columns the list actually renders.