标签：#pos

Protecting data that must stay secret ten years from now is a problem for today : an adversary can capture your encrypted traffic now and decrypt it once quantum capability exists ( harvest now, decrypt later ). Quipu is a free hybrid post-quantum encryption library for data at rest: it combines proven classical cryptography with the new kind, so that it only breaks if both fall at once. Pure Rust, and why Quipu started out aiming at several languages: a Rust core with a C ABI on top and bindings for Python, Node and Go. It worked, but the lesson was clear: maintaining a stable C interface plus four bindings, each with its own packaging and interoperability tests, was complexity that did not pay for itself against the real goal — protecting data at rest — and it widened the attack surface with unsafe we did not want. Today Quipu is pure Rust : memory safe, no garbage collector, no first-party unsafe . And for people who do not write Rust, it ships as a native Python wheel via PyO3 — the surface that non-Rust users actually need. One codebase, one thing to audit. It is the same philosophy that guides the rest: where good cryptography exists, reuse it; simplicity is a security decision, not a convenience. Installation cargo add quipu # Rust pip install quipu-crypto # Python (native wheel, PyO3) Encrypt and decrypt in Python import quipu # Symmetric, with a passphrase blob = quipu . encrypt_stream ( b " sensitive data " , " my-passphrase " ) assert quipu . decrypt_stream ( blob , " my-passphrase " ) == b " sensitive data " # Post-quantum, for a recipient pub , sec = quipu . generate_keypair () # X25519 + ML-KEM-1024 c = quipu . encode_to_recipient ( b " secret " , pub ) assert quipu . decode_as_recipient ( c , sec ) == b " secret " What is underneath Encryption: XChaCha20-Poly1305 (authenticated AEAD). Key derivation: Argon2id (brute-force resistant) + HKDF. Post-quantum: X25519 + ML-KEM-1024 for keys; Ed25519 + ML-DSA-87 for signatures. Security level: NIST category 5

Python PostgreSQL with asyncpg: Async Database Operations asyncpg is the fastest PostgreSQL driver for Python — pure asyncio, no thread overhead, and up to 3× faster than psycopg2 on typical workloads. It is the go-to choice for any async Python backend. Installation pip install asyncpg # PostgreSQL server must already be running Connect and Create a Pool import asyncio import asyncpg from datetime import datetime DATABASE_URL = " postgresql://user:password@localhost:5432/mydb " async def create_pool () -> asyncpg . Pool : pool = await asyncpg . create_pool ( DATABASE_URL , min_size = 2 , max_size = 10 , command_timeout = 30 , server_settings = { " application_name " : " myapp " }, ) print ( " Pool created. " ) return pool Schema Setup CREATE_TABLES = """ CREATE TABLE IF NOT EXISTS users ( id BIGSERIAL PRIMARY KEY, username TEXT NOT NULL UNIQUE, email TEXT NOT NULL UNIQUE, created_at TIMESTAMPTZ NOT NULL DEFAULT now() ); CREATE TABLE IF NOT EXISTS posts ( id BIGSERIAL PRIMARY KEY, user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE, title TEXT NOT NULL, body TEXT NOT NULL DEFAULT '' , published BOOLEAN NOT NULL DEFAULT FALSE, created_at TIMESTAMPTZ NOT NULL DEFAULT now() ); CREATE INDEX IF NOT EXISTS idx_posts_user ON posts(user_id); CREATE INDEX IF NOT EXISTS idx_posts_created ON posts(created_at DESC); """ async def setup_schema ( pool : asyncpg . Pool ) -> None : async with pool . acquire () as conn : await conn . execute ( CREATE_TABLES ) print ( " Schema ready. " ) INSERT — Adding Records async def create_user ( pool : asyncpg . Pool , username : str , email : str ) -> int : async with pool . acquire () as conn : row = await conn . fetchrow ( """ INSERT INTO users (username, email) VALUES ($1, $2) ON CONFLICT (username) DO UPDATE SET email = EXCLUDED.email RETURNING id, created_at """ , username , email , ) return row [ " id " ] async def create_post ( pool : asyncpg . Pool , user_id : int , title : str , body : str , published : bool = False , ) ->

Startups building B2B products reach for multi-tenancy in PostgreSQL the same way on day one: one shared database, one set of tables, and a tenant_id column marking who owns each row. That is the correct call, and it stays correct for a long time. However, when that column is enforced by application code rather than by the database, a single forgotten predicate stops being a bug and becomes a disclosure event, and a disclosure event is one of the very few engineering failures that lands straight on your balance sheet as stalled enterprise deals, an unplanned legal bill, and a security review you can no longer pass. By understanding what multi-tenancy actually guarantees, which isolation model fits your stage, and how Row-Level Security moves that guarantee out of your codebase, startup CTOs and Fractional CTOs can make the tenant boundary hold without slowing the team down. (If you want to skip the theory, jump straight to the connection pooler trap that switches Row-Level Security off in production, what it costs in query performance, or when it is genuinely time to leave the shared schema.) Because "enforced by application code" means something very specific in practice. It means a promise that everyone will remember to filter on tenant_id , and that promise is the single most expensive line of undocumented policy in your entire codebase, because it holds perfectly for about fourteen months, right up until the afternoon a tired engineer ships a reporting endpoint that joins four tables and forgets the predicate on exactly one of them, and then a customer opens a dashboard and sees somebody else's invoices. That is not a bug. A bug is something you fix on Monday. A cross-tenant data leak is a disclosure event, which means legal gets involved, your enterprise prospects get an email from their own security team, and the deal that was supposed to close your Series A quietly moves to next quarter and then to never. The uncomfortable part is that this is not a story abo

How I Built a Wedding Planning Suite with Supabase in 3 Months Quick Answer: I built a full wedding planning platform in 90 days using Supabase as the backend (PostgreSQL database, real-time subscriptions, Row Level Security, and OAuth auth), Next.js 14 for the frontend, and a few carefully chosen npm packages for specific features like QR code scanning. The key was leveraging Supabase's managed services to avoid building auth, websockets, and file storage from scratch. Introduction Three months ago, I had an idea: what if couples could plan their entire wedding through one cohesive platform? Not a static checklist app, but a living, breathing system where vendors, guests, budgets, and timelines all talked to each other in real time. I'm a solo developer with a day job. I didn't have a team of backend engineers to build authentication, real-time sync, or file storage infrastructure. I needed a stack that would let me ship fast without shipping broken. Enter Supabase. I'd heard the "Firebase alternative" pitch before, but what I discovered was something far more powerful for developers who actually want to own their data and their SQL. This is the story of how I built WedPlanner—a full wedding planning suite—with Supabase, Next.js, and a few other tools. No VC funding. No offshore team. Just me, a tight deadline, and a PostgreSQL database that never let me down. Why Supabase? The Architecture Decision That Made Everything Possible When you're building alone, every architectural decision compounds. Pick the wrong database, and you'll spend weeks fighting migrations. Pick the wrong auth solution, and you'll ship with security holes you don't even know about. I evaluated Firebase, PlanetScale, Clerk, and rolling my own PostgreSQL on RDS. Here's why Supabase won: PostgreSQL, not a proprietary document store. Wedding data is relational. A guest belongs to a wedding. A vendor has multiple bookings. A budget category has many line items. Trying to model this in Firestore's

Choice Setup burden Incident evidence Best fit Hosted metrics API Low Good if event context is preserved Small teams with an on-call rotation Postgres plus a custom dashboard Medium Excellent for joining metrics to business records Low-volume systems with strong SQL skills Self-hosted metrics stack High Configurable, but operationally demanding Teams that already run observability infrastructure Short answer: start with a hosted metrics dashboard API, send a small set of custom application metrics from Node.js, and retain reconstruction fields in Postgres. Choose the custom Postgres path when joins are the investigation, or self-hosting when data control outweighs maintenance. That recommendation has a catch. A chart can show when enrollment failures rose, but it cannot explain which course, release, region, or feature state produced them unless those dimensions were recorded at write time. For an edtech SaaS, the real deliverable isn't a pretty dashboard. It is enough evidence to replay the story of a customer incident without guessing. How can Node.js send custom app metrics to a hosted dashboard API? Capture the dimensions an investigator can act on: metric name, timestamp, deployment identifier, region, tenant or school identifier, operation, outcome, and a bounded error class. Keep direct student data out of labels. A useful event might say that lesson_publish failed validation in the EU region on deployment 7f3c2a1 ; it should not contain a learner's name, email, answer, or free-form support message. Small is good. Stop there. Start with service-level signals tied to customer work: request count, failure count, latency distribution, queue depth, and the age of the oldest queued job. Add business-flow counters such as course publication attempts only when they answer a concrete incident question. Don't export every database column as a label. High-cardinality dimensions make charts harder to read, alerts harder to tune, and the ingestion boundary harder to reas

Here is the disk layout of one mobile mapping survey — a vehicle with a LiDAR scanner and a panoramic camera, driven along a road: data/001_MMS/ 507 MB point cloud orbit/oblak/ 566 MB spherical photos trajectory/*.gpkg 108 KB the path the vehicle drove Just over a gigabyte. The database this feeds holds 2.3 GB in total — for 2.7 million road features across a hundred layers. Two more surveys and the binary data outweighs everything the database has ever stored. So the question isn't how to put a point cloud in Postgres. It's what you put in Postgres instead . The trajectory is the index Of that gigabyte, one file goes into the database: the 108 KB trajectory, a GeoPackage holding the line the vehicle drove. That line is what makes the survey findable. It draws on the map with everything else. You can ask which surveys cover a junction, which are newest, whether a stretch of road has been captured since the resurfacing. All the questions people actually ask are questions about where and when , and the trajectory answers every one of them at 0.01% of the storage. The heavy files never enter the database. The row holds paths: class Cloud ( models . Model ): name = models . CharField ( max_length = 120 , db_index = True ) path_name = models . CharField ( max_length = 120 ) # -> octree metadata JSON orbit_url = models . CharField ( max_length = 255 ) # -> spherical photo index spherical_photo = models . BooleanField ( default = False ) recording_date = models . DateField ( null = True ) source_srid = models . IntegerField ( null = True , choices = SOURCE_SRID_CHOICES ) available = models . BooleanField ( default = True ) Metadata, geometry, and pointers. That's the whole trick, and it isn't clever — it's just the discipline to not reach for a bytea column. Why not in the database Postgres will happily store a gigabyte. It's the access pattern that kills you. A browser point cloud viewer doesn't fetch a point cloud. It fetches an octree : a tree of small files, and as the

The schema catalog for an AI assistant is the artefact that answers the question "what does this database look like right now". Whether the database is Postgres, MySQL, SQL Server or Redshift, the shape of the problem is the same: the catalog carries table names, column names, types, keys, and enough relationships to let the assistant write a query that resolves. It lives somewhere between the database and the assistant, has to stay in sync with a database that changes underneath it, and is almost always built the same weekend the team decides they want an AI assistant reading their data. It runs fine for the first three tables. The problems start around the fourth week, and none of them look like the same problem twice. The distinction worth naming early is between the connection layer (how the assistant reaches the database) and the knowledge layer (what the assistant knows about the database's shape). The connection layer receives most of the attention, because credentials, network isolation and query cost are visible failure modes and easy to argue about. The knowledge layer is where most of the actual quality of the assistant lives, and it decays quietly. The AI database context page covers why this second layer matters at all when the first one exists. Why not just point the assistant at the database Connecting the AI directly to production is the shortest path and the one most teams reject after five minutes of thinking about it. The assistant would get read access on tables it should not see, its queries can be arbitrarily expensive, its credentials would live somewhere they should not, and the audit trail becomes hard to reason about. What most teams end up building is a layer in between: a representation of the database that the assistant can read cheaply and safely without ever touching production. That layer is what this article is about. It is not the connection. It is the catalog. The five recipes teams build Ask fifteen senior developers how to build

The PostgreSQL manual is unusually direct about this: When an application receives this error message, it should abort the current transaction and retry the whole transaction from the beginning. "The whole transaction" is doing a lot of work in that sentence, and it is the part that gets dropped. TypeORM issue #9806 — "Auto Retry options on error in transactions (e.g. Deadlock)" — has been open since February 2023. Thirty 👍, six comments, no implementation. Meanwhile typeorm-transactional , at 188,000 downloads a week, ships @Transactional() with isolation levels and seven propagation modes and no retry at all. So the ecosystem's actual answer to "how do I use SERIALIZABLE in Node" is: don't. Use READ COMMITTED , don't think about write skew, and hope. I spent a while building the thing that issue asks for. The short version of what I found: the feature as literally requested cannot be built correctly , and the reason is more interesting than the feature. The implementation everyone reaches for first Wrap the query. It's the obvious move — the error came from a query, so retry the query: async function withRetry < T > ( fn : () => Promise < T > , attempts = 3 ): Promise < T > { for ( let i = 1 ; ; i ++ ) { try { return await fn (); } catch ( e ) { if ( i >= attempts || ! isSerializationFailure ( e )) throw e ; await sleep ( 50 * i ); } } } await dataSource . transaction ( ' SERIALIZABLE ' , async ( em ) => { const from = await em . findOneOrFail ( Account , { where : { id : fromId } }); const to = await em . findOneOrFail ( Account , { where : { id : toId } }); await withRetry (() => em . decrement ( Account , { id : fromId }, ' balance ' , amt )); // ← here await withRetry (() => em . increment ( Account , { id : toId }, ' balance ' , amt )); // ← and here }); This does nothing. Worse than nothing — it turns one clear error into a confusing one. When PostgreSQL raises 40001 , it does not fail that statement . It aborts the entire transaction . The connection is now

If an LLM is generating PostgreSQL in your application, there is one moment worth treating separately: after the model returns SQL, but before your code calls db.query() . Prompt rules are useful. They can make the model more likely to produce the sort of query you want. They do not decide which tables the application is allowed to read, whether multiple statements are acceptable, or whether a function call should run. I have been working on sql-guard , a TypeScript package for that gap. It parses PostgreSQL into an abstract syntax tree (AST), checks the tree against an explicit policy, and rejects anything it cannot validate confidently. Why I did not want to check SQL with regex SQL is structured. A query may have joins, subqueries, aliases, unions, and common table expressions (CTEs). Checking raw text can catch an obvious keyword, but it cannot reliably answer what the query actually does. For example: SELECT * FROM public . users ; SELECT 1 ; DELETE FROM public . users ; WITH removed AS ( DELETE FROM public . users RETURNING id ) SELECT * FROM removed ; All three examples contain SELECT , but they are not equivalent. The second has two statements. The third uses a data-modifying CTE. A validator needs to understand the query structure rather than look for a few strings. An AST makes that possible. It lets the validator inspect statement types, source tables, function calls, and nested expressions. It also means an alias or CTE name cannot conceal the base table being read. The policy is the important part sql-guard is built around allowlists. You state what a particular feature may use, and the validator checks the generated SQL against that list. Here is a small policy for an assistant that can look at users and orders: import { validate } from ' sql-guard ' ; const policy = { allowedTables : [ ' public.users ' , ' public.orders ' ], allowedFunctions : [ ' count ' , ' lower ' ], }; const result = validate ( ' SELECT lower(u.email) FROM public.users AS u ' , po

Proteger datos que deben seguir siendo secretos dentro de diez años es un problema de hoy : un adversario puede capturar tu tráfico cifrado ahora y descifrarlo cuando exista la capacidad cuántica ( harvest now, decrypt later ). Quipu es una librería libre de cifrado híbrido post-cuántico para datos en reposo: combina criptografía clásica probada con la nueva, de modo que solo se rompe si ambas caen a la vez. Rust puro, y por qué Quipu nació apuntando a varios lenguajes: un núcleo en Rust con una C ABI encima y bindings para Python, Node y Go. Funcionaba, pero la lección fue clara: mantener una interfaz de C estable más cuatro bindings, cada uno con su empaquetado y sus pruebas de interoperabilidad, era complejidad que no pagaba para el objetivo real —proteger datos en reposo— y ampliaba la superficie de ataque con unsafe que no queríamos. Hoy Quipu es Rust puro : memoria segura, sin garbage collector , sin unsafe de primera parte . Y para quien no programa en Rust, se distribuye como rueda nativa de Python (vía PyO3) — que es la superficie que el cliente que no es de Rust de verdad necesita. Una sola base de código, una sola cosa que auditar. Es la misma filosofía que guía el resto: donde hay buena criptografía, se reutiliza; la simplicidad es una decisión de seguridad, no una comodidad. Instalación cargo add quipu # Rust pip install quipu-crypto # Python (rueda nativa, PyO3) Cifrar y descifrar en Python import quipu # Simétrico con contraseña blob = quipu . encrypt_stream ( b " datos sensibles " , " mi-passphrase " ) assert quipu . decrypt_stream ( blob , " mi-passphrase " ) == b " datos sensibles " # Post-cuántico para un destinatario pub , sec = quipu . generate_keypair () # X25519 + ML-KEM-1024 c = quipu . encode_to_recipient ( b " secreto " , pub ) assert quipu . decode_as_recipient ( c , sec ) == b " secreto " Qué hay debajo Cifrado: XChaCha20-Poly1305 (AEAD autenticado). Derivación de claves: Argon2id (resistente a fuerza bruta) + HKDF. Post-cuántico: X25519

There is a layer in my database called 1 . Somebody created it, presumably by accident, and it sat there for months looking harmless. It was the only layer in the system that never served a single tile, and nobody noticed, because it was empty anyway. That layer turned out to be a symptom of a SQL injection vulnerability. This post is about the design that produced it — which I still think is a good design — and the four things I got wrong inside it. The setup A web GIS with about 2.7 million features: 1.8 million points, 697,000 lines, 172,000 polygons. Users create layers through the UI, upload data into them, edit geometry, and expect to see it on a map. The features do not live in a table per layer. They live in three tables — one for points, one for lines, one for polygons — with a layer_id foreign key and a JSON column for attributes: project_pointfeature 1,820,288 rows project_linefeature 697,009 rows project_polygonfeature 171,830 rows That's a deliberate trade. A table per layer means DDL every time a user clicks "new layer", a migration story that never ends, and a schema that drifts. Three generic tables mean one schema, one set of indexes, and layers that are just rows in a metadata table. The cost lands on the tile server. The pattern Martin serves vector tiles from PostGIS. Point it at a database and it discovers spatial tables and views and publishes each as an MVT endpoint. It can be told to publish views but not tables: postgres : auto_publish : from_schemas : [ public ] publish_tables : false reload_interval : 5s So: give every layer its own view. A Django post_save signal on the Layer model creates it: CREATE OR REPLACE VIEW t19_saobracajni_znakovi AS SELECT f . id , f . feature_attrs , f . geom , f . layer_id , l . name AS layer_name , lg . name AS layer_group_name , p . title AS project_title FROM project_pointfeature f JOIN project_layer l ON f . layer_id = l . id JOIN project_layergroup lg ON l . layer_group_id = lg . id JOIN project_project p

This is a submission for DEV's Summer Bug Smash: Clear the Lineup , powered by Sentry . Project Overview mini-agent is a public FastAPI backend for an AI support-agent demo. Its test suite covers API behavior, authentication, rate limiting, approval flows, and PostgreSQL/pgvector-backed retrieval. The GitHub Actions workflow starts PostgreSQL and Redis service containers before running the Python test suite. The application database initialization also executes: CREATE EXTENSION IF NOT EXISTS vector The dependency is also visible in the DocumentChunk.embedding column, which uses pgvector's Vector type. That made the database image part of the test contract, not just incidental infrastructure. Bug Fix or Performance Improvement On August 12, 2026, the CI run for the preceding commit reached the test step and failed: Failed workflow run Commit tested by that run The workflow was using the general-purpose postgres:17-alpine service image, while the application required the pgvector extension during database initialization. The test environment therefore did not match the database capability required by the code. The failure was specific enough to avoid a broad rewrite: the container initialized successfully, dependency installation passed, and the workflow stopped only at Run tests . That pointed to the application/database boundary rather than the GitHub Actions runner or Python installation. The fix changed one line: services: postgres: - image: postgres:17-alpine + image: pgvector/pgvector:0.8.6-pg17 Full change: Use pgvector image in CI The PostgreSQL major version, credentials, port mapping, health check, application environment, dependency installation, and test command all remained unchanged. This kept the patch narrow and made the CI database expose the same required extension as the application. Code The evidence is a direct before-and-after pair: The preceding workflow failed at Run tests . The one-line database-image commit triggered a new workflow. The new

자동으로 돌아가게 만든 것과, 자동으로 끝까지 처리되는 것은 다른 문장이었습니다 이 시스템은 사람 승인 없이 스스로 판단하고 매매하는 걸 목표로 설계했습니다. 실계좌 주문 실행과 안전장치 (새 창)도 그 목표에 맞춰 만들었습니다. 그런데 최근 한 달 사이 실계좌에서 세 번, 사람이 직접 개입해야 하는 상황이 있었습니다. 세 사례 모두 "왜 자동 로직이 이 상황을 못 넘겼는지"의 구조가 서로 달랐습니다. 1. 배분 규칙이 특정 주문을 구조적으로 굶겼다 특정 종목 하나가 여러 날째 매도 계획이 서 있는데도 계속 팔리지 않는 걸 발견했습니다. 시스템은 매일 이 종목을 매도 후보로 올렸지만, 실제 주문까지는 못 갔습니다. 원인은 하루 매매 한도를 여러 라운드에 나눠 배분하는 규칙이었습니다. 이 종목의 주문 금액이 그날 남은 매도 한도보다 항상 컸습니다. 라운드 순서를 아무리 바꿔도 통과할 수 없는 구조였습니다. 한도 자체는 정상 작동하고 있었습니다. 문제는 "이번엔 못 나가도 다음 기회에 나간다"는 전제가 이 종목엔 애초에 성립하지 않았다는 점입니다. 잔여 한도가 매번 주문 금액보다 작으면, 기회는 계속 오지만 한 번도 충분하지 않습니다. 당장 못 나간 주문 1건은 사람이 직접 처리했습니다. 실계좌에서 이뤄진 되돌릴 수 없는 매도였습니다. 이후 배분 규칙 자체를 손봐서 같은 구조로 다시 굶는 일이 없도록 정리했습니다. 2. 안전장치가 스냅샷과 누적치를 혼동했다 다른 날엔 반대 방향의 사고가 있었습니다. 누적 손실을 감지하는 안전장치가 정상적인 매수 2건을 잘못 차단했습니다. 지수는 그날 거의 보합이었는데, 이 안전장치가 재는 손실률은 훨씬 크게 찍혀 있었습니다. 원인을 보니 이 장치는 "고점 대비 누적 하락"을 감지하는 용도였는데, 정작 비교하는 현재값은 장중 순간 스냅샷이었습니다. 장중 잠깐의 변동이 누적 지표를 밀어 올려서, 실제로는 발동하면 안 될 상황에서 발동한 겁니다. 누적을 재는 장치와 순간을 재는 장치가 뒤섞여 있었던 셈입니다. 막힌 매수 2건은 사람이 판단해서 직접 집행했습니다. 이후 이 안전장치가 장중 순간값이 아니라 "그날 마감 대 전날 마감" 기준으로만 반응하도록 구조를 바꿨습니다. 장중 급락에는 이제 다른 안전장치가 대신 반응하도록 역할을 나눴습니다. 3. 개입 경로 자체가 "새로 사는 경우"를 몰랐다 두 번째 사례를 수습하는 과정에서 사고가 하나 더 있었습니다. 수동으로 낸 주문을 원장에 반영하는 도구를 썼는데, 반영이 안 되고 조용히 빠졌습니다. 이 도구는 사람이 손으로 낸 거래를 세 가지 경우 중 하나로 분류합니다. 기존 보유 종목을 판 경우, 기존 보유 종목을 더 산 경우, 그리고 시스템과 무관한 거래인 경우입니다. 그런데 이번 매수는 원장에 없던 새 종목을 사람이 처음 사들인 경우였습니다. 세 분류 중 어디에도 안 맞았고, 도구는 이걸 "시스템과 무관한 거래"로 잘못 넘겼습니다. 그 결과 실제로는 산 자산이 잠깐 원장 밖에 있는 것처럼 표시됐습니다. 이 도구는 애초에 사람 개입을 위해 만든 경로였습니다. 그런데 그 경로를 설계할 때, "사람이 아예 새로운 자리에 처음 진입하는 경우"는 상정하지 않았습니다. 개입 경로 자체가 개입의 한 형태를 놓치고 있었던 셈입니다. 순서(먼저 다른 매도를 부기하고, 그다음 이 매수를 부기)를 지켜서 바로 수습했고, 검증 결과 원장과 실계좌 잔고는 정확히 일치했습니다. 분류 로직에 이 경우를 추가하는 건 아직 남은 과제입니다. 세 사례를 묶어보면 셋 다 "자동으로 처리되게 만들었다"와 "실제로 끝까지 처리된다"가 다른 문장이라는 걸 보여줬습니다. 첫 번째는 규칙이 있었지만 그 규칙이 특정 입력에서 절대 통과할 수 없는 구조였습니다. 두 번째는 장치가 있었지만 재는 대상(순간 대 누적)이 설계 의도와 어긋나 있었습니다. 세 번째는 사람 개입을 위한 경로가 있었지만 그 경로 자체가 특정 개입 형태를 몰랐습니다. 세 가지 모두 "자동화가 이 케이스를 놓칠 수 있다"는 걸 사전에 안 게 아니라, 실제로 놓친 뒤에야 알았습니다. 일반화하면 완전자동을 목표로 설계할수록,

Making something run automatically and having it actually get handled to completion turned out to be two different sentences This is the English version of a post originally written in Korean for my algorithmic trading system devlog (new tab). I designed this system to judge and trade on its own, without needing human approval for each decision. The order execution and safety-guard layer (new tab) was built around that same goal. Over the past month, though, there were three separate moments where I had to step in and act directly on the live account. Each one failed for a structurally different reason. 1. An allocation rule structurally starved one order I noticed a particular ticker had a sell plan queued for several days running, yet it never actually went out. The system kept nominating it as a sell candidate every day, but the order never reached execution. The cause was the rule that splits the daily trading budget across multiple rounds. This position's order size was consistently larger than whatever sell budget remained that day. No matter how the rounds were reordered, it could never clear. The budget cap itself was working exactly as designed. The problem was that the underlying assumption — "if it doesn't clear this time, it'll clear next time" — never held for this position. New opportunities kept arriving, but none of them was ever big enough. I executed the one blocked order by hand. It was an irreversible sell on the live account. Afterward, I reworked the allocation rule itself so the same starvation pattern couldn't recur. 2. A safety guard confused a snapshot with a cumulative reading On a different day, the opposite kind of failure happened. A guard meant to detect cumulative drawdown wrongly blocked two legitimate buy orders. The index was nearly flat that day, but the loss figure this guard was tracking read much larger. Looking closer, the guard was designed to measure "decline from peak," but the current value it compared against was an intra

로그조차 안 쌓이니, 돌고 있는지 죽어 있는지 구분할 방법이 없었습니다 이 블로그의 개발일지는 매일 밤 자동으로 마무리됩니다. 그날 대화로 초안을 썼으면 변환해서 로그에 남기고, 없으면 스킵했다는 한 줄만 남깁니다. 최근 이 파이프라인을 들여다볼 일이 있었는데, 7월 24일 이후로 로그가 통째로 비어 있었습니다. 무슨 일이 있었나 자동화 로그( .automation.log ) 마지막 줄이 2026-07-24였습니다. 그 뒤로 8월 22일까지, 거의 한 달 가까이 스킵 기록조차 한 줄도 없었습니다. 자동화가 아예 안 돌았나 싶어서 실행 로그( cron_output.log )를 열어봤습니다. 그런데 거기엔 매일 밤 실행된 흔적이 빼곡했습니다. 날짜 확인하고, 초안 있으면 내용 정리하고, 크로스링크까지 챙긴 요약이 매일 밤 남아 있었습니다. 일은 하고 있었는데, 결과물만 하나도 남지 않고 있었던 겁니다. 왜 아무도 몰랐나 실행 로그를 읽어보니 원인은 매일 같았습니다. 파일 쓰기 권한 승인을 기다리다가 그대로 끝난 겁니다. "workspace has not been trusted"라는 경고가 매 실행마다 찍혀 있었습니다. 초안을 잘 정리해놓고도, 마지막 파일 쓰기 한 줄이 승인 대기에 막혀서 아무것도 저장되지 않은 채 세션이 끝나는 패턴이 한 달 가까이 반복됐습니다. 문제는 이게 하필 로그를 남기는 단계 자체가 막힌 상황 이었다는 겁니다. 스킵한 날엔 스킵했다는 한 줄도 못 남겼습니다. 그러니 로그만 보면 "자동화가 멈췄다"와 "쓸 게 없어서 조용했다"를 구분할 수가 없었습니다. 무인 자동화이니 매일 밤 누가 화면을 지켜보는 것도 아닙니다. 결과적으로 이 공백은 사람이 우연히 로그 파일을 열어보기 전까지는 발견될 방법이 없는 구조였습니다. 진짜 원인 원인은 신뢰(trust) 설정이었습니다. 이 헤드리스 자동화 세션은 프로젝트 폴더 단위로 파일 쓰기 권한을 신뢰받아야 동작하는데, 그 신뢰 설정 키가 이 블로그 폴더가 아니라 상위 디렉터리(프로젝트들이 모여 있는 루트) 단위로 걸려 있었습니다. 즉 이 블로그 폴더만 놓고 보면 "아직 한 번도 대화형으로 신뢰 승인을 받은 적 없는 새 작업공간" 취급을 받고 있었던 셈입니다. 설정 파일 안에 이미 허용 규칙 10개가 들어 있었는데도, 그 규칙들이 걸려 있는 범위 자체가 무시되고 있었습니다. 헤드리스로 도는 야간 자동화는 대화형 승인 프롬프트에 응답할 사람이 없습니다. 범위가 어긋난 신뢰 설정 하나가, 매일 밤 정확히 같은 지점에서 조용히 실행을 무력화하고 있었던 겁니다. 흥미로운 디테일 하나 — 유령 완료 기록 이 공백을 되짚어보다가 특이한 줄 하나를 발견했습니다. 8월 22일 낮 12시 41분에 "weekly: 완료"라는 로그 한 줄이 남아 있었는데, 그 시각에 대응하는 실제 산출물 파일은 없었습니다. 같은 날 오후 4시에 다시 수동으로 실행된 기록이 있었고, 이번엔 실제 파일까지 정상적으로 만들어졌습니다. 앞선 12시 41분 기록이 왜 실물 없이 "완료"라고만 남았는지는 원인을 특정하지 못했습니다. 권한 문제가 한창이던 구간이라 어떤 형태로든 쓰기 절차 일부만 성공하고 일부는 실패한 걸로 추정만 할 뿐입니다. 다만 이 한 줄은 별도로 눈에 띄는 교훈을 남겼습니다. "완료"라고 적힌 로그도 그 자체로 완전히 믿을 수는 없다 는 겁니다. 로그와 실제 산출물을 따로 대조하지 않았다면 이 유령 기록을 그냥 지나쳤을 겁니다. 어떻게 고쳤나 신뢰 설정을 이 블로그 폴더 기준으로 다시 걸어주니, 그날 밤부터 바로 정상화됐습니다. 별도의 복잡한 조치는 필요 없었습니다. 문제는 고치는 방법이 아니라, 한 달 가까이 그 문제를 놓치고 있었다는 사실 쪽이었습니다. 일반화된 교훈 이번 일로 다시 확인한 건, 무인 자동화에서 "로그가 없다"는 상태 자체가 하나의 신호라는 겁니다. 그런데 그 신호를 신호로 취급하려면, 애초에 "침묵"과 "성공적인 무동작"을 구분할 수 있게 설계돼 있어야 합니다. 이번 파이프라인은 스킵한 날에도 로그 한 줄을 남기게 되어 있었습니다. 그 설계 덕분에, "로그가 아예 안

In this article, we review useEditorContext in n8n codebase. You will learn: Composables in Vue useEditorContext as composable in n8n. Composables in Vue In the context of Vue applications, a "composable" is a function that leverages Vue's Composition API to encapsulate and reuse stateful logic. When building frontend applications, we often need to reuse logic for common tasks. For example, we may need to format dates in many places, so we extract a reusable function for that. This formatter function encapsulates stateless logic: it takes some input and immediately returns expected output. There are many libraries out there for reusing stateless logic - for example lodash and date-fns , which you may have heard of. By contrast, stateful logic involves managing state that changes over time. A simple example would be tracking the current position of the mouse on a page. In real-world scenarios, it could also be more complex logic such as touch gestures or connection status to a database. This is just like React Hooks. Learn more about Composables . useEditorContext as composable in n8n. Now that we understand what a composable is in Vue.js, btw, n8n editor-ui is written in Vue, let's understand how useEditorContext is used. Below is a comment I picked from useEditorContext.ts file. /** * Per - editor host overrides for the current editor context . * * Editor hosts ( e . g . the Instance AI artifact preview ) scope their embedded * editor by providing ` EditorEnabledFeaturesKey ` - the capabilities the host * supersedes . AI features can only be restricted: an explicit ` false ` turns one * off , while omitted ( or ` true `) features fall back to their store values . * ` readOnly ` is a direct flag - ` true ` forces the canvas read - only . When no host * provides the key , AI features fall back to their store values and the canvas * is editable (` readOnly ` is ` false `) . * ` executionSuccessToasts ` / ` executionErrorToasts ` are direct flags too - each * ` true `

A manual psql check answers exactly one question: does this policy work right now, against today's schema, with today's roles. It says nothing about tomorrow. Three ordinary changes are enough to quietly break tenant isolation without anyone noticing at review time. A migration that drops and recreates a table loses RLS entirely, since it's a per-table flag, not something that travels with column definitions. A new service role for a background job can skip the policy if nobody remembers to apply it. And the most common one: someone grants BYPASSRLS during an incident and never revokes it. Most guides point you at pgTAP here and stop. pgTAP is fine, but it's a separate SQL-based framework with its own runner. If your backend is already on Jest, you don't need a second test framework, you need a Jest test that actually proves a leak can't happen. The core pattern: seed a row as tenant A, query as tenant B, assert the result is empty. Run it through a dedicated low-privilege role, since table owners and superusers bypass RLS by default even with FORCE enabled for the owner. I break down the full pattern, the queryAsTenant helper, testing WITH CHECK on INSERT/UPDATE, catching accidental BYPASSRLS grants, and wiring it into GitHub Actions here: https://devencyclopedia.com/blog/postgres-rls-testing-jest If you're doing this across more than one or two tables, I also built RLSBuilder, a browser tool that generates the CREATE POLICY SQL and a matching Jest test from the same three inputs so they can't drift apart: https://devencyclopedia.com/tools/rls-builder

Mark (aka Winsaucerer) here to show you how you can test your PostgreSQL database like a sorcerer. We are going to be using Spawn, a SQL build system supporting migrations and testing. You do not need to be using Spawn for migrations in order to use it for testing. Spawn does not require any extension installed. All you need is the spawn CLI and a psql connection to the database for Spawn to connect through. Spawn was built to solve some migration pains I've experienced, but I happily discovered that when used for testing, it is very powerful. To show you some of that power, we're going to use a contrived database example. It uses golden file testing to determine success. When the test runs, we capture the stdout and stderr output from psql, and compare that to expected output. Testing with Spawn involves these steps: Create a new test with spawn test new <name> and fill out the test steps Check test outputs with spawn test run <name> (or view the SQL that will be sent to psql via spawn test build <name> ) When outputs are as expected, create the golden file with spawn test expect <name> Run the test and compare to expected output with spawn test compare <name> For now, Spawn only supports connecting via psql, which means that you have access to all the features that psql provides. To get started, follow the Spawn install instructions: Install Spawn And then create a new folder on your system, and initialise a new project with a docker compose config ready for us to play with: # inside your new folder: spawn init --docker docker compose up -d You now have a running docker based PostgreSQL database and a spawn.toml file configured to connect to it. We are not assuming that you are using Spawn or any other tool for migrations, so you can manually create and update the database by connecting directly using psql: docker exec -ti postgres-db psql -U postgres Create the database ⚠️ Caution This post is not intended as an example of how to build an orders database. The des

Hello, I'm Maneshwar. I'm building git-lrc, a Micro AI code reviewer that runs on every commit. It is...

Disclosure: I build Schemity , a desktop ERD tool - this post is from our blog and uses it for the examples. TL;DR: The database has a built-in place to document a column - COMMENT ON COLUMN in PostgreSQL, the COMMENT attribute in MySQL - and almost nobody fills it in, because a sentence of prose has to travel the same path as a schema change: a migration file, a review, a deploy. Schemity keeps field descriptions in the diagram instead, where editing one generates no SQL, reads existing database comments in on import, and exports the result as a data dictionary. You can document a database column without touching the database: write the description in the model rather than in the schema. That sounds like a dodge until you price the alternative. The database's own mechanism for column documentation, COMMENT ON COLUMN in PostgreSQL and the COMMENT attribute in MySQL, sends a sentence of prose down exactly the same path as a change to how data is stored - a migration file, a code review, an approval, a deploy window - and on MySQL it does something worse than that. Schemity keeps field descriptions in the diagram, where editing one produces no SQL at all. This is why so many production schemas have thousands of columns and almost no comments. Not because nobody wanted to write them. Because writing one costs a deploy. How do I document a database column without running a migration? Keep the description in the model rather than in the storage engine. A field description is a fact about what the column means to your team; it changes no type, no constraint, no index, and nothing about what the database will accept. When it lives in the diagram, editing it is like editing a comment in a code file: you change it, review it in the same pull request as everything else, and nothing has to run against production for it to take effect. The moment that description is a column comment, it stops being prose and becomes DDL. Now it needs a migration file, and the migration needs a