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PostgreSQL provides several planner configuration parameters, such as enable_seqscan and enable_indexscan , that influence how execution plans are generated. These settings affect planning, not the execution of an already-generated plan. With prepared statements, this raises an interesting question. Should planner settings be applied before PREPARE, before EXECUTE, or both? Let's look at a simple example: a "tasks" table with a due date and a "done" status: \ c drop table if exists tasks ; -- a table of tasks with status (done or not) and due date create table tasks ( id bigint generated always as identity primary key , due timestamptz , done boolean ); -- insert 500 tasks, with 1% not done insert into tasks ( due , done ) select now () + interval '1 day' * n , 42 != n % 100 from generate_series ( 1 , 500 ) n ; -- index the todo (partial index) create index on tasks ( due , id ) where done = false ; vacuum analyze tasks ; With a partial index, I indexed only the tasks that are not yet done ( done = false ) because that's my most frequent query pattern: postgres =# explain select id , due , done from tasks where done = false and id > 0 order by due limit 1 ; QUERY PLAN --------------------------------------------------------------------------------------- Limit ( cost = 0 . 13 .. 3 . 60 rows = 1 width = 17 ) -> Index Scan using tasks_due_id_idx1 on tasks ( cost = 0 . 13 .. 17 . 47 rows = 5 width = 17 ) Index Cond : ( id > 0 ) ( 3 rows ) With partial indexes, the condition covered by the index is not even visible in the execution plan because the index itself enforces the condition. Prepared statement I decided to use a prepared statement with all values as parameters. It is probably not a good idea in this case. When a parameter can have only a few different values and you expect different cardinalities for each, you should probably define one query per value, using literals. I'm doing this to illustrate what can happen, with a simple, extreme example: postgres =# pr

Episode 1/4 of the mini-series The week Supabase lied to me 4 times . The three following episodes cover a mutation silently swallowed by the SDK [CANONICAL URL EPISODE 2: to fill in after push], an RLS recursion resolved by a JWT hook [CANONICAL URL EPISODE 3: to fill in after push], and a query that stops at exactly 1000 rows without saying so [CANONICAL URL EPISODE 4: to fill in after push]. The Tuesday the security probe spoke It's 9:12am on a Tuesday in May. The daily drift probe has been running automatically for three weeks — an aclexplode query across all public objects, filtered on anon . I don't open it every morning. That morning, it's waiting for me with a row that has no business being there. Niran sets a coffee on the corner of my desk without a word. He reads the output over my shoulder. A PII backup table — personal data in plaintext, created two days earlier for a bulk reclassification — shows up in the list with SELECT , INSERT , UPDATE , DELETE granted to anon . Accessible to any unauthenticated curl request. He lets three seconds pass and says: "It's not RLS." Then he goes back to his hoodie. He's right. It's not an RLS bug. The table itself is open, at the GRANT layer, before RLS even applies. Three objects, three doors, one mechanism That week, I realize I'm not dealing with an isolated incident. Three distinct objects, in three different migrations, each open a door nobody thought they'd opened. The backup table first. Then a policy set TO public because the public landing page needs it, which lets a POST {} from anon through with an HTTP 400 NOT NULL response instead of 401 Unauthorized . And finally four SECURITY DEFINER functions written to execute transactional operations with their owner's privileges, all invocable by anon because EXECUTE defaults to TO PUBLIC at CREATE time. Three objects, three superficially distinct mechanisms, yet one shared root. At every CREATE , Postgres completes the migration with an implicit GRANT the author nev

The problem with a data breach is not finding evidence. It is connecting it. But let me start where I actually was: 4 AM, last day of the hackathon, staring at this in my terminal. RateLimitError: GroqException - Rate limit reached for model `llama-3.3-70b-versatile` on tokens per day (TPD): Limit 100000, Used 99787, Requested 1616. Please try again in 20m12s. Used 99,787 out of 100,000. My deployment was half done, my demo graph was empty on the server, and the free tier had 213 tokens left. The submission deadline was hours away. I had not slept. I had not eaten. My friends were asleep and I was swapping API keys like a gambler swapping chips. This post is the story of how we got there, and how it ended at 7 in the morning with the best sigh of relief I have ever taken. First, some honesty about how I got here When I joined my first WeMakeDevs hackathon, I did not believe in it. I thought it was one of those ordinary online events. Fake prizes, no follow-through, what would I even get out of it. I joined anyway, mostly out of boredom, got into the Discord, talked to people, made a few connections. I landed in the top 50. A few days later an email showed up: a free Claude Max subscription as a gift. I read it twice. I genuinely could not believe a hackathon had actually delivered something. So when this hackathon opened, I did not hesitate. I messaged my friends and said we are joining as a team this time. Three of us: me (Mehraan), Aqib, and Ubaid. The spark We spent the first evening in our group chat throwing ideas around and shooting most of them down. Then one of my friends dropped a thought that stuck: what happens after a company gets hacked? I started digging into it. The answer is honestly depressing. After a breach, the evidence is everywhere. VPN records. File access logs. The email gateway. Badge readers at the office doors. CCTV. HR notes. Anonymous tips. Each system tells one small piece of the story, and a human analyst has to stitch all of it togeth

SQLite Internals, Postgres 19 Checksums, & PL/CBMBASIC Extension Today's Highlights This week, we delve into SQLite's secure deletion and blob updates, explore upcoming data integrity features in PostgreSQL 19, and discover a unique PostgreSQL extension bringing Commodore 64 BASIC to your database. These updates offer insights into database internals, future resilience, and creative extensibility for the SQLite ecosystem. Secure Delete and BLOB Updates in SQLite (SQLite Forum) Source: https://sqlite.org/forum/info/6f3e886a1149c97e0ede9a243281efb05a043705393ea94437ed7c0556315972 This SQLite forum discussion delves into the nuances of secure data deletion and efficient BLOB updates within SQLite databases. Secure deletion is a critical concern for applications handling sensitive data, where simply deleting a row might not zero-out the underlying storage, leaving recoverable remnants. The thread explores methods and implications for ensuring data is truly eradicated when removed, potentially touching on PRAGMA settings or specific file system interactions. Understanding these mechanisms is crucial for developers building secure, embedded applications with SQLite. The conversation also extends to optimizing updates for BLOB (Binary Large Object) data. Efficiently handling large binary data, such as images or documents, in an embedded database like SQLite requires careful consideration to avoid performance bottlenecks and excessive disk I/O. The discussion likely covers strategies for in-place updates, managing free space, and the internal workings of SQLite's storage engine when dealing with variable-length BLOBs. This insight helps developers make informed decisions on schema design and update patterns for improved application performance and data integrity. Comment: This thread offers valuable insights into SQLite's low-level data management, essential for anyone needing to implement robust security or optimize BLOB storage. PostgreSQL 19 to Feature Checksums For All

Introduction I used to think "connecting to a database" was one skill. Turns out it's two: connecting to a database chilling quietly on your own laptop, and connecting to one living in the cloud, behind a login, in this case, an SSL certificate that will not let you in until you treat it with respect. This week I did both. Same tool (Power BI), same dataset, two very different vibes. Grab a coffee, here's the full walkthrough local PostgreSQL first, then Aiven's cloud version, side by side, screenshots and all. Part 1: Local PostgreSQL → Power BI Step 1 : Create a schema Nothing fancy, just giving my table a home: CREATE SCHEMA powerbi ; Step 2 : Import the dataset Right-click the new schema → Import Data in DBeaver, point it at your CSV, and let the wizard do its thing. Step 3 : Check the table landed properly A quick peek at the columns to make sure nothing got mangled on the way in. Step 4 : Connect Power BI In Power BI Desktop: Get Data → Database → PostgreSQL database. In the Server field, type localhost (or 127.0.0.1 ) and your database name. localhost Choose Import , hit OK, and log in with your local username and password. Click Load . That's it. That's the whole local experience. Part 2: Aiven PostgreSQL (Cloud) → Power BI Now for the part that actually taught me something. Step 1 : Grab your connection details Everything you need lives on Aiven's Overview page: Host, Port, Database name, User, SSL mode. Your service URI will look something like this (don't worry, this isn't a real password, Aiven masks it in the console): postgres : // avnadmin : •••••••• @ pg - xxxxxxxx - yourproject . c . aivencloud . com : 22016 / defaultdb ? sslmode = require Step 2 : Import the dataset into Aiven Same DBeaver wizard as before, just pointed at the Aiven connection instead of local. CREATE SCHEMA powerbi ; Step 3 : Aiven's certificate. Download the CA cert from the Overview page: Now here's the part that actually tripped me up: Power BI's PostgreSQL connector doesn't ha

Introduction Fixing N+1 queries with select_related / prefetch_related or selectinload (see the previous post ) gets you down to a small, sane number of queries per request. The next bottleneck is what each query costs once the table has millions of rows — and that is almost always about indexing. An index turns "scan every row" into "look it up directly." Skip it, and a query that's instant in development takes seconds once real data volume shows up in production. How Indexes Work: The B-Tree Intuition Without an index, a WHERE clause forces a sequential scan : the database reads every row and checks the condition — O(n) , cost grows linearly with table size. An index is a separate, sorted structure (almost always a B-tree ) mapping column values to row locations. Because it's sorted and balanced, finding a value is a tree walk: O(log n) . On a 10-million-row table, that's the difference between reading 10 million rows and roughly 23 tree nodes. This isn't free: Writes get slower — every INSERT / UPDATE / DELETE on an indexed column also updates the index. Storage grows — each index is a sorted copy of (part of) the data. An index trades write cost and storage for read speed. Indexing a column you rarely filter or sort on is pure cost, no benefit. Reading Query Plans: EXPLAIN ANALYZE Postgres' EXPLAIN ANALYZE shows what the planner actually did, not an estimate. Before an index , filtering orders by customer_id : EXPLAIN ANALYZE SELECT * FROM orders WHERE customer_id = 48291 ; Seq Scan on orders (cost=0.00..21453.00 rows=42 width=96) (actual time=0.021..118.442 rows=41 loops=1) Filter: (customer_id = 48291) Rows Removed by Filter: 1199959 Planning Time: 0.112 ms Execution Time: 118.471 ms Seq Scan means Postgres read all ~1.2 million rows and discarded all but 41. actual time is real elapsed time — 118ms for one lookup. After CREATE INDEX idx_orders_customer_id ON orders (customer_id); : Index Scan using idx_orders_customer_id on orders (cost=0.42..8.53 rows=42 wid

Introduction Fixing N+1 queries (see the previous post ) gets your Hibernate app down to a handful of queries per request. The next bottleneck is what each of those queries costs once your tables have millions of rows — and that is almost always a question of indexing. An index turns "scan every row" into "look it up directly." Get the index wrong — or skip it — and a query that took 2ms in development takes 4 seconds in production once real data volume shows up. How Indexes Work: The B-Tree Intuition Without an index, a WHERE clause forces a sequential scan : the database reads every row and checks the condition. That's O(n) — cost grows linearly with table size. An index is a separate, sorted data structure (almost always a B-tree ) that maps column values to row locations. Because it's sorted and balanced, finding a value is a tree walk: O(log n) . On a 10-million-row table, that's the difference between reading 10 million rows and reading roughly 23 tree nodes. The cost is not free: Writes get slower. Every INSERT / UPDATE / DELETE on an indexed column must also update the index structure. Storage grows. Each index is a copy of (part of) the data, sorted differently. An index is a trade: you pay on every write so that specific reads become fast. Indexing a column you rarely filter or sort on is pure cost with no benefit. Reading Query Plans: EXPLAIN ANALYZE Postgres' EXPLAIN ANALYZE shows what the planner actually did — not what you hope it did. Before an index , filtering orders by customer_id : EXPLAIN ANALYZE SELECT * FROM orders WHERE customer_id = 48291 ; Seq Scan on orders (cost=0.00..21453.00 rows=42 width=96) (actual time=0.021..118.442 rows=41 loops=1) Filter: (customer_id = 48291) Rows Removed by Filter: 1199959 Planning Time: 0.112 ms Execution Time: 118.471 ms Seq Scan means Postgres read all ~1.2 million rows and threw away all but 41 of them. actual time is the real elapsed time, not an estimate — 118ms for one lookup. After CREATE INDEX idx_orders

Notes from shipping a real-world PWA in Korea: Vite SSG is worth it. SPAs lose Korean SEO because Naver's crawler doesn't fully render JS. Leaflet > Mapbox for cost-sensitive projects. Free OSM tiles + zero cost. Firebase Hosting rewrites let you have deep URLs (/city/suwon) without a backend. KakaoTalk share is non-negotiable in Korea — 70%+ of social traffic. PWA install banner: don't auto-prompt, let the user discover. Project: https://gyeonggi-currency-map.web.app?ref=devto&utm_source=devto&utm_medium=social&utm_campaign=multi-site-bot

Introduction As data volumes continue to grow, running aggregation queries directly on raw datasets becomes increasingly expensive. Business dashboards, analytics platforms, and reporting systems often execute the same calculations repeatedly—such as total sales, daily active users, page views, or revenue trends. While ClickHouse® is designed to process analytical workloads at remarkable speed, repeatedly scanning billions of records still consumes valuable CPU, memory, and storage resources. This is where AggregatingMergeTree proves its value. Rather than calculating aggregates every time a query is executed, AggregatingMergeTree stores intermediate aggregation states that are merged automatically in the background. This approach allows analytical queries to read compact, pre-aggregated datasets, resulting in dramatically faster response times and reduced infrastructure costs. In this guide, you'll learn how AggregatingMergeTree works, why aggregate states matter, how to build an automated aggregation pipeline using Materialized Views, and when this engine is the right choice for your ClickHouse® workloads. What is AggregatingMergeTree? AggregatingMergeTree is a specialized ClickHouse® table engine designed to store aggregate function states instead of raw records. Unlike the standard MergeTree engine, which stores every inserted row, AggregatingMergeTree keeps partially aggregated values that ClickHouse combines during background merge operations. This significantly reduces the amount of data that must be processed when generating analytical reports. Because much of the computational work happens during data ingestion, dashboards and reporting applications can retrieve summarized information much more efficiently. Typical scenarios include: Sales reporting Website traffic analytics Financial summaries IoT sensor monitoring Business KPI dashboards Application observability metrics Why Use AggregatingMergeTree? Imagine an online marketplace processing millions of tr

A client wanted to know who was on their site and on which page, the way Tidio's widget showed them — but without paying for a Tidio subscription, on an external WordPress site that doesn't use Firebase. The result: an external tracker hooked to an independent Firebase project, live presence via onDisconnect , persistent history in Firestore with IP geolocation — and a final debugging session where a browser CORS error was masking a server crash caused by an empty string instead of null . The context The client already had a third-party live-chat script installed on their site, and that's where the idea came from: "can we see who's on the site and on which page, without using that service?" Two constraints made the request less trivial than usual: the site hadn't been migrated to my usual stack yet — it was still running on WordPress, on different hosting — and there was no intention of introducing Firebase on the WordPress side. Step 1 — understanding what a live-chat widget actually does Before building anything, it was worth looking at what the already-installed script actually did. The tag pasted into the site was just a small loader: it creates a hidden iframe, loads the widget's real "brain" inside it from the provider's servers, which then connects via websocket to their backend to stream presence, current page and events in real time. The interesting part — "see who's on the site and on which page" — isn't in the public script: it all lives server-side at the provider, behind authentication, a proprietary dashboard and a subscription. There was nothing to "detach" from that service: it's client code tied to someone else's backend by design. But the pattern itself — a script tag hooking into an external backend — is exactly what's needed to build the same feature independently, and it fits well with Firebase, which has a native presence mechanism built for precisely this. Step 2 — live presence with Firebase Realtime Database Firebase Realtime Database has a

If you ask any senior backend engineer or database administrator how to instantly make a slow, disk-bound application faster, their first answer is almost always: "Put it in memory." But why is memory so preferred, and how do modern architectures utilize RAM to achieve sub-millisecond latencies? We're seeing a massive revival of RAM disks and in-memory architectures. Let's explore why computer experts are increasingly treating RAM like a hard drive. 1. The Physics of Storage: Why RAM Wins To understand the shift towards in-memory architectures, we have to look at the numbers. Hard Disk Drives (HDDs): Mechanical spinning disks. Seek times are around 2-5 milliseconds . Solid State Drives (SSDs): Flash memory. Seek times are around 0.1 milliseconds (100 microseconds) . RAM (Random Access Memory): Volatile silicon. Access times are around 100 nanoseconds . RAM is roughly 1,000 times faster than an SSD and 10,000 to 50,000 times faster than an HDD. When you have a high-throughput system serving millions of requests per second, waiting for a disk to seek is an eternity. 2. In-Memory Databases: Redis and Memcached The most common implementation of this principle in modern backends is the In-Memory Database . How They Work Instead of writing every transaction to an SSD, systems like Redis and Memcached store the entire dataset directly in RAM. This bypasses the OS file system cache, disk I/O bottlenecks, and complex B-tree traversals required by traditional relational databases like PostgreSQL or MySQL. The Trade-off: Durability RAM is volatile. If the server loses power, all data is gone. So how do in-memory databases survive crashes? Snapshots (RDB in Redis): Periodically dumping the entire memory state to disk. Append-Only Files (AOF in Redis): Logging every write operation to a disk sequentially. Sequential writes to disk are significantly faster than random writes. This hybrid approach gives you the read/write speed of RAM with a "good enough" durability guarantee for

Author: Tobie Morgan Hitchcock Today we're launching Scale, a new tier of SurrealDB Cloud built for the workloads you can't afford to have go down. Our first tier, Start, was designed for building and shipping fast. Scale is designed for what happens next: production traffic, uptime commitments, and the kind of resilience your users never notice because there are always available nodes. It's the tier for teams running SurrealDB as the scalable context layer behind real applications and AI agents in production. What you get with Scale Scale is about one thing: keeping your database available and consistent under real-world conditions. Highly-available, fault-tolerant clusters. Scale runs your database as a multi-node cluster designed to survive node and infrastructure failures without dropping writes or losing consistency. A single point of failure is no longer a single point of downtime. Multiple availability-zone deployment. Your cluster is distributed across multiple availability zones, so even the loss of an entire zone doesn't take your database with it. Traffic keeps flowing while the cluster recovers in the background. Horizontal scale. As demand grows, Scale grows with it. Add capacity by scaling out across nodes rather than being capped by the size of a single machine. Start with three nodes, and keep adding to scale your application or agent's needs. See more information about SurrealDB Cloud Scale architecture here . Built on SurrealDS Scale is powered by SurrealDS , SurrealDB's distributed storage engine and the foundation that makes all of this possible. SurrealDS is a new generation distributed storage architecture, rethought from first principles. Instead of coupling storage to compute on a single box or to a proprietary cloud tier, SurrealDS embeds consensus directly in SurrealDB nodes and separates the two layers cleanly. Here's what that architecture gives you. Architecture overview Compute and storage separation. Scale compute for QPS and storage f

In the rush to build AI agents, we defaulted to complex vector databases. But high-traffic platforms are converging on a simpler, more robust foundation: plain files. Most long-term agent memory setups are massively over-engineered. When developers start building LLM applications, the default prescription is almost always: "Spin up a managed vector database and build a RAG pipeline." But if you look at the highest-traffic production agent platforms (like Claude Code, Manus, and OpenClaw), a quieter trend has emerged. They are bypassing the enterprise embeddings store and using plain markdown files as their primary memory substrate. This is not a regression to simplicity. Done well, it is a stronger engineering foundation because files are inspectable, diffable, portable, and git-native. But a folder of plain text notes with no structure is just a slow, poorly indexing database. To make a file-first architecture work at scale, you must follow a fundamental system design principle: separate storage from search . The Core Invariant: Storage vs. Search The single highest-leverage decision you can make in agent memory design is treating your storage layer and search indexes as completely separate systems. Storage (Canonical Source of Truth): Versioned, human-readable files (Markdown + YAML frontmatter). Search (Derived Index): Derived search structures (vector databases, full-text BM25 indexes, entity graphs, keyword indexes). In this architecture, every search index is treated as a disposable artifact. You can delete your vector embeddings database or rebuild your entity graph at any time, with zero loss of underlying memory. This buys you three advantages: Auditability for free: By storing memories in text files, you can version-control them using Git. Every memory update, supersession, or correction is diffable, attributable, and reversible without any custom database versioning logic. Algorithmic freedom: Swap your embedding models, adjust your chunking strategies, o

AWS released Managed Knowledge Bases for Amazon Bedrock on 17 June 2026. The feature significantly reduces the operational complexity of building Retrieval-Augmented Generation (RAG) solutions by allowing Bedrock to manage the vector storage, indexing, embeddings, and retrieval infrastructure on your behalf. For teams looking to deliver an Agent Core proof of concept or their first production RAG workload quickly, this can be a compelling option. However, there are some important trade-offs to understand before committing to the managed approach. Traditionally, a Bedrock Knowledge Base required a customer-managed vector store such as: OpenSearch Serverless OpenSearch Managed Clusters Aurora PostgreSQL with pgvector Pinecone DocumentDB Other supported vector databases With a Managed Knowledge Base, Bedrock handles the underlying vector infrastructure and embedding model selection for you. Creating one from the AWS CLI is straightforward: aws bedrock-agent create-knowledge-base \ --name "my-managed-kb" \ --role-arn "arn:aws:iam:: ${ AWS_ACCOUNT_ID } :role/service-role/AmazonBedrockExecutionRoleForKnowledgeBase_ihv1p" \ --knowledge-base-configuration '{ "type": "MANAGED", "managedKnowledgeBaseConfiguration": { "embeddingModelType": "MANAGED" } }' Advantages Lower operational overhead There is no need to provision, secure, monitor, patch, or scale a separate vector database. Lower costs S3 storage is cheaper than database storage. Pay only for each ingestion and retrieval operation. Indexing and searching compute is free. No 24/7 server costs. Faster time-to-value Managed Knowledge Bases make it possible to stand up a RAG solution in minutes rather than days. Automatic embedding management Bedrock manages embedding selection and indexing, reducing the number of architectural decisions required from development teams. Cost-effective for smaller workloads The managed model can be attractive for: Proofs of Concept Departmental knowledge bases Agent Core pilots Workloads wi

Sign-in worked flawlessly in dev. Then a real user pasted a real code and got "invalid format" — before the code ever reached Supabase. The credential was fine. My regex was wrong. Here's the one-line assumption that broke auth for every human who wasn't me. I run a Discord-native Company Brain. Teams /save docs and /ask grounded answers; access is gated by a magic-link claim that emails a one-time code. Standard GoTrue OTP flow. The client shows a box, you paste the code, the server verifies it. Boring — which is exactly what auth should be. The bug: a six-digit assumption in a validation guard The claim handler did a cheap client-side sanity check before calling verifyOtp : // The bug. Looks reasonable. Rejects every real code. const OTP = /^ \d{6} $/ ; function normalize ( input : string ): string { const code = input . trim (); if ( ! OTP . test ( code )) throw new Error ( " Enter the 6-digit code from your email. " ); return code ; } Every OTP tutorial uses \d{6} . Every code demo shows six digits. So I typed six digits into the test and it passed. In dev I was generating my own codes and never actually reading the email. Supabase's GoTrue emits an eight-digit code on this project. ^\d{6}$ rejects eight digits outright. The user's perfectly valid credential got thrown out by my own front door with a lie for an error message — "enter the 6-digit code" when the email plainly showed eight. Why it happens: OTP length is a setting, not a constant The length of a GoTrue email OTP is configurable — GOTRUE_MAILER_OTP_LENGTH (Dashboard → Authentication → Email). It defaults to six in many setups and to eight in others depending on when and how the project was provisioned. The number in the tutorial is that author's project setting , not a property of OTPs. Hardcoding 6 couples your client to a server config you don't control and might change. Bump the length for security later and every client silently starts rejecting valid codes. No error in your logs — the rejection

Quick Answer (TL;DR) Modifying an RDS instance class in place causes 5 to 15 minutes of downtime while AWS reboots the database. To right-size without downtime, use RDS Blue/Green Deployments (fastest, cleanest), a read-replica promotion (works on older engines), or a Multi-AZ failover to a resized standby. Blue/Green is the 2026 default for most workloads on MySQL, MariaDB, Postgres, and now SQL Server. Why this happens RDS instances are Managed EC2 hosts running the DB engine, and a class change (say db.m6i.large to db.m6i.xlarge ) requires stopping the process, migrating the EBS volumes to a new host, and restarting. AWS's default "modify" workflow does this in place and warns you about downtime. The workarounds exist because that reboot is unacceptable for user-facing services, so you build the new instance alongside the old one and cut over. Fix #1: Use RDS Blue/Green Deployments The 2026 default. Available for RDS MySQL, MariaDB, PostgreSQL, and SQL Server (added mid-2025). Steps: In the RDS console, select the instance and choose Actions → Create Blue/Green Deployment . Set the Green instance to your target instance class. AWS creates a full standby using logical replication, keeps it in sync, and validates health. When ready, click Switch over . Cutover typically takes under 60 seconds. Applications reconnect using the same endpoint. Command-line equivalent: aws rds create-blue-green-deployment --blue-green-deployment-name resize-prod --source arn:aws:rds:... --target-db-instance-class db.m6i.xlarge Best when: your engine supports it and you can tolerate the extra cost of running two instances for the sync window. Fix #2: Read-replica promotion For engines or versions that do not yet support Blue/Green, or for cross-region resizing. Steps: Create a read replica with the desired new instance class. Wait for the replica to catch up (near-zero lag). Point application writes to the read replica endpoint (requires connection-string change or DNS switch). Promote

Data Modeling, Relationships, and Schemas in Data Analytics In the fields of data analytics, data warehousing, and database management, modeling and schema design are the fundamental pillars used to organize and query information efficiently. This article provides a comprehensive guide to these core concepts. 1. Data Modeling Data modeling is the architectural process of designing how data is stored, interconnected, and accessed within a system. Core Questions Addressed: Storage: What specific data points need to be captured? Structure: How should individual tables be organized? Connectivity: How do these tables interact with one another? Levels of Data Models: Conceptual Model: A high-level business perspective focusing on entities and their relationships, devoid of technical specifications. Logical Model: Defines specific attributes, keys, and relationships. It is independent of the Database Management System (DBMS). Physical Model: The actual implementation within a database, including technical details like indexes, partitions, and storage requirements. 2. Relationships Relationships define the logic of how data in one table corresponds to data in another. One-to-One (1:1): A single record in Table A relates to exactly one record in Table B. One-to-Many (1:M): The most common relationship; for example, one Customer can place many Orders . Many-to-Many (M:M): Multiple records in one table relate to multiple records in another. This requires a Junction Table (Bridge Table) to function. Example: One Student can enroll in many Courses, and one Course contains many Students. 3. SQL Joins Joins are used to combine rows from two or more tables based on a related column. Join Type Description Inner Join Returns only the records that have matching values in both tables. Left Join Returns all records from the left table and the matched records from the right. Right Join Returns all records from the right table and the matched records from the left. Full Outer Join Returns

I've been building on DynamoDB since around 2015, and these days I build tools for it: dynoxide , a DynamoDB engine, and Nubo , a native client. So I'm not neutral about it. It's the first database I reach for, and with reason - the operational overhead is close to nil, no connections to pool or instances to size, and it holds the same single-digit-millisecond reads whether the table has a thousand items or a billion. The data modelling is a craft, and a satisfying one. It's also one of the harder databases to learn, and that's the part I keep coming back to. DynamoDB punishes the instincts you bring from SQL. You don't normalise and join at read time; you work out the questions your app will ask first, and shape the data around those access patterns, until one table answers all of them. It's a real shift in how you think, and it's where a lot of people bounce off - it feels backwards right up until it clicks. The people who teach it best all teach it the same way. Alex DeBrie's The DynamoDB Book , the arc.codes team's examples, Rick Houlihan's re:Invent talks - the legendary ones, where he models half a dozen access patterns onto a single table at a hundred miles an hour - none of them hand you rules to memorise. They show you patterns and make you run them. I learned a lot of my DynamoDB from all three, and it stuck because I was building as I went. That last part is the bit that's hard to come by on your own. Reading about an access pattern and having it in your fingers are different things, and to run one - build the table, write the items, fire the query and see what comes back - you need an AWS account, or a local emulator installed and seeded. Enough friction that plenty of people read about single-table design without ever building one. There was a second thing pulling the same way. dynoxide had learned to run in the browser only last month, compiled to WebAssembly with no server behind it, and it was a preview I didn't fully trust. What it needed was a real

"That would be an awesome capability."

My dashboard had a useMemo doing arithmetic it had no business doing. It was a Pokémon TCG Pocket collection tracker, but that part doesn't matter. What matters is that the home page needed to show three things: overall completion, completion per set, and which set you were closest to finishing. The way I'd built it, the browser was fetching every card and every owned record, then grinding through the math on each render to figure all of that out. It worked. It also got slower and harder to read every time the data grew or I added a metric. So I moved the aggregation out of React and into Postgres, and the surprising result was that my frontend got boring . Fewer hooks, less state, almost nothing left to break. That's the whole argument of this post: aggregation belongs in the database, and when you put it there, the React code that's left over is the kind of boring you actually want in the layer your users touch. What "fetching everything into React" actually looks like Here's the shape of the original dashboard. Load all the cards, load the user's owned rows, then derive everything on the client. const [ cards , setCards ] = useState < Card [] > ([]); const [ owned , setOwned ] = useState < OwnedCard [] > ([]); useEffect (() => { ( async () => { const { data : allCards } = await supabase . from ( " cards " ). select ( " * " ); const { data : ownedRows } = await supabase . from ( " user_cards " ) . select ( " card_id " ); setCards ( allCards ?? []); setOwned ( ownedRows ?? []); })(); }, []); const ownedIds = useMemo (() => new Set ( owned . map (( o ) => o . card_id )), [ owned ]); const perSet = useMemo (() => { const groups : Record < string , { total : number ; have : number } > = {}; for ( const card of cards ) { const g = ( groups [ card . set_id ] ??= { total : 0 , have : 0 }); g . total += 1 ; if ( ownedIds . has ( card . id )) g . have += 1 ; } return groups ; }, [ cards , ownedIds ]); const overall = useMemo (() => { const total = cards . length ; const ha