Nik Samokhvalov NikolayS

Verified Spec-Driven Development (VSDD)

The Fusion: VDD × TDD × SDD for AI-Native Engineering

Overview

Verified Spec-Driven Development (VSDD) is a unified software engineering methodology that fuses three proven paradigms into a single AI-orchestrated pipeline:

Spec-Driven Development (SDD): Define the contract before writing a single line of implementation. Specs are the source of truth.
Test-Driven Development (TDD): Tests are written before code. Red → Green → Refactor. No code exists without a failing test that demanded it.

When analyzing Postgres query execution plans, it is recommended using the BUFFERS option:

explain (analyze, buffers) <query>;

Example:

test=# explain (analyze, buffers) select * from t1 where num > 10000 order by num limit 1000;
                                                                QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------

test=# \timing
Timing is on.
test=#
test=#
test=# create table t1 as select i from generate_series(1, 1000000) _(i);
SELECT 1000000
Time: 660.804 ms
test=# create unique index i_t1 on t1(i);
CREATE INDEX

	<!doctype html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<title>samogrow Landing Redesign — design proposal</title>
	<meta name="description" content="Five artboards proposing a two-voice redesign of the samogrow.dev landing page: warm field-guide editorial paired with a precise console register.">
	<style>
	:root{--paper:#f2ede0;--card:#f7f3e8;--ink:#1c2216;--ink-soft:#4a5340;--ink-faint:#636b59;
	--line:#cdc4ac;--leaf:#35722f;--leaf-dk:#2b5c26;

	#!/usr/bin/env python3
	# -- coding: utf-8 --
	# Draw psql output as iTerm2 v3 inline graph using matplotlib
	# Author: Alexander Korotkov <aekorotkov@gmail.com>
	# with a few edits by nik@postgres.ai to support Python3

	import sys
	import re
	import warnings
	import matplotlib

	set timezone to 'EST';

	with data(t) as (
	select timestamp '2019-01-01 12:00'
	)
	select
	t,
	pg_typeof(t),
	t at time zone 'UTC',
	pg_typeof(t at time zone 'UTC')

	create schema dba;

	-- on GCP's Cloud SQL for Postgres, if we work with more than one DB user,
	-- we have a problem – some queries are not visible (`<insufficient privilege>`),
	-- so we need to use a workaround
	create or replace function dba.pgss_snapshot() returns setof pg_stat_statements as $$
	declare
	rec pg_stat_statements;
	_role text;
	begin

	-- based on pg_stat_statements only
	with data as (
	select
	lower(regexp_replace(query, '^\W(\w+)\W+.$', '\1')) word,
	count(*) cnt,
	sum(calls) calls,
	sum(total_time) total_time
	from pg_stat_statements
	--where not query ~* '^\W*set\W+' -- uncomment this to exclude `SET ...`
	group by 1