System Design
Every database we've met so far stores facts: a user's name, an order's total, a sensor's reading, a word in a document. The newest member of the family stores something stranger and more powerful: meaning itself. Vector databases are the data system
System Design
There's a kind of data that has quietly exploded in volume over the last decade, and you generate it constantly without thinking. Every time a server reports its CPU usage, every time an app records how long a request took, every time a thermostat notes the temperature, every
System Design
Type a few words into a search box and, in a fraction of a second, you get back the most relevant results out of millions or billions of documents, ranked best-first, with your typos forgiven and suggestions appearing as you type. We're so used to this that
System Design
Every database we've covered so far has one job: running an application. They store orders as they're placed, serve profiles as they're viewed, accept writes as they happen. This is the live, operational heartbeat of a product, and it's called OLTP, online
System Design
Every database family we've covered so far treats relationships as a secondary concern. Relational databases reconstruct them with joins at query time. Document databases mostly avoid them by nesting data. Key-value and wide-column stores barely acknowledge them. But for a whole class of important problems, the
System Design
After the elaborate machinery of relational, document, and wide-column databases, the key-value store is almost a relief. It is the simplest possible database, and that simplicity is exactly where its power comes from. There is no schema to design, no query language to learn, no joins to reason
System Design
Some data does not arrive politely. It pours. Think of every tap and swipe in a mobile app, every message in a chat platform, every reading from a fleet of sensors, every location ping from a fleet of vehicles, every line of a log from thousands of servers. This is
System Design
The relational database we covered in the last deep-dive is brilliant at one thing above all: taking your data apart into tidy, non-repeating tables. That is its great strength. But it is also, for some kinds of work, its great inconvenience. A lot of the time, the thing
System Design
If you only ever learn one kind of database deeply, make it this one. The relational database has been the default way to store important data for over forty years, and despite a parade of trendy alternatives, it is still the right answer for the majority of systems being built
System Design
If you have ever looked at a modern system's architecture diagram, you have probably wondered the same thing every newcomer wonders: why are there so many different databases in here? There is a relational database over here, something called a document store over there, a cache, a search
System Design
Here is a question that sounds simple but trips up most people new to software: once an engineer finishes writing code, how does it actually reach the millions of people using the product? It does not just "go live." Between a developer typing the last line of code
System Design
How teams know a system is healthy, and how they decide how healthy it needs to be There is an old engineering saying: you cannot fix what you cannot see. A running system is a black box from the outside, millions of things happening per second, and the only way