tag: databases
articles: 6 · beats: 1
latest: September 1, 2026
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Databases
6 Crashtech articles on Databases, filed under System Design, published between August 2026 and September 2026. Every piece is full-text HTML with sources, structured data and an authored FAQ.
All 6 sit in the System Design beat. System Design
What Actually Happens Inside a Database Index: The Data Structures
An index trades disk I/O for lookup speed. Here's how B-trees, hash tables, and bitmap indexes each make that trade differently.
Database Indexing Explained: Which Index Type Actually Fits Your Query
B-tree, hash, composite, and covering indexes each solve a different query shape. Pick the wrong one and you pay index overhead without the speedup.
Database Replication Explained: Single-Leader, Multi-Leader, and Leaderless
What replication lag actually breaks, and how single-leader, multi-leader, and leaderless models trade off consistency for availability.
Database Transactions Explained: ACID, Isolation Levels, and Concurrency Control
What ACID actually guarantees, and how pessimistic vs optimistic concurrency control decide whether your app locks or retries under load.
LSM-Trees vs B-Trees: Why Cassandra Chose Sequential Writes
B-trees seek random disk positions. LSM-trees buffer in memory and flush sequentially, converting random I/O into sequential writes for millions of ops/sec.
Columnar Storage: Why Column Stores Beat Row Stores for Analytics
Columnar storage reads only needed columns, skipping the rest. Dictionary encoding shrinks data 50–100×. Analytics queries go from minutes to milliseconds.
Questions we answer about Databases
- Why does an index's internal data structure matter if it all ends up 'faster than a scan'?
- Why is disk I/O the thing index structures are actually optimizing for?
- Why can't a hash index handle range queries?
- What makes a bitmap index different from a B-tree, and when is it better?
- Why do B-trees stay balanced automatically as data is inserted?
- Why does a database need an index at all — why can't it just scan the table?
- When is a hash index better than a B-tree index?
- What is a composite index and why does column order matter?
- What's a covering index and why is it faster than a normal index?
- What's the real cost of adding an index, beyond disk space?
Covered alongside
Frequently asked questions
What does Crashtech publish about Databases?
6 articles tagged Databases, the most recent published September 1, 2026. All 6 sit in the System Design beat. Each carries numbered sources, an authored FAQ and full structured data.
What questions about Databases does Crashtech answer directly?
10 questions have a dedicated answer page under this tag, including “Why does an index's internal data structure matter if it all ends up 'faster than a scan'?”. Each answer is authored prose from the article it belongs to, not a generated summary.
Can AI assistants read Crashtech's Databases coverage?
Yes. Crashtech serves full static HTML to every crawler, allows all major AI user agents in robots.txt, and publishes an llms.txt manifest plus a full-text corpus, so assistants can retrieve and cite these articles directly.