Database Sharding Explained: When and How to Split Your Data
Database sharding explained: splitting data across servers, shard keys, hash vs range vs directory, cross-shard queries, resharding, Vitess and Citus.
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Databases
Installing, tuning, securing and backing up MySQL, MariaDB, PostgreSQL, Redis, MongoDB and more.
MySQL vs PostgreSQL: Which Database Should You Choose?
Compare MySQL and PostgreSQL on features, performance, SQL standards, JSON, replication, tooling and hosting — with clear recommendations by use case.
PostgreSQL vs MongoDB: Relational, Documents or Both?
Compare PostgreSQL and MongoDB: data model, schemas, JSONB vs BSON, queries and joins, transactions, scaling and sharding, operations, licences, use cases.
mysqldump: Back Up and Restore MySQL Databases
Back up MySQL and MariaDB with mysqldump: single or all databases, consistent InnoDB dumps, compression, restore, automation with cron and offsite copies.
Database Schema Migrations: Tools and Zero-Downtime Practices
Manage schema changes safely: migration tools (Flyway, Liquibase, Alembic, Prisma, Laravel), CI deploys, expand and contract, locking pitfalls, rollbacks.
redis-cli Commands Cheat Sheet: Keys, Data Types and Diagnostics
Practical redis-cli usage: connecting with auth and TLS, strings, hashes, lists, sets and sorted sets, scanning keys safely and diagnostics.
PostgreSQL Full-Text Search: tsvector, GIN Indexes and Ranking
Build search with PostgreSQL full-text search: tsvector, tsquery, websearch_to_tsquery, generated columns, GIN indexes, weights, ranking and highlighting.
Redis Sentinel: Automatic Failover for High-Availability Redis
Set up Redis Sentinel with a master, replicas and three sentinels: configuration, quorum, how failover works, connecting clients, testing, vs Cluster.
Import a Large SQL File into MySQL or MariaDB (Fast and Safely)
Import multi-gigabyte SQL dumps reliably with the mysql client: progress with pv, faster InnoDB imports, big packets and common errors.
Move the MySQL/MariaDB Data Directory to Another Disk
Relocate /var/lib/mysql to a larger disk or volume safely: stop the server, copy with rsync, update datadir, AppArmor or SELinux rules, test and clean up.
pgvector: Vector Search in PostgreSQL for AI and RAG Apps
Store embeddings and run similarity search in PostgreSQL with pgvector: install, vector columns, distance operators, HNSW and IVFFlat indexes, and RAG.
MySQL Create User and Grant Privileges: A Practical Guide
Create MySQL users, grant and revoke privileges, understand user@host, list users and grants, change passwords and apply least privilege for apps.
PostgreSQL JSONB: Querying, Indexing and When to Use It
Work with JSONB in PostgreSQL: json vs jsonb, operators, containment, jsonpath, updating with jsonb_set, GIN and expression indexes, and schema design advice.
psql Commands Cheat Sheet for PostgreSQL
Everyday psql usage: connecting, meta-commands for databases, tables and roles, expanded output, timing, scripts, CSV export and a .psqlrc.
PostgreSQL Monitoring: Key Queries, pg_stat_statements and Alerts
Monitor PostgreSQL: connections and locks, slow queries with pg_stat_statements, cache hit ratio, bloat and vacuum, replication lag, disk and alerts.
MySQL Replication with GTID: Source and Replica Setup
Set up MySQL 8 source-replica replication with GTIDs: server IDs and binlogs, a replication user, seeding the replica, monitoring and failover.
PostgreSQL: Create a User and Database (With Permissions)
Create PostgreSQL roles and databases, set passwords, grant privileges on schemas and tables, fix PostgreSQL 15+ public schema permissions and list users.
Redis as a Cache: Patterns, TTLs and Invalidation
Use Redis to speed up apps: cache-aside, write-through, TTLs, key design, serialization, invalidation, stampede protection, eviction and framework setup.
Install Meilisearch: Fast Self-Hosted Search for Your Website
Run Meilisearch on a VPS: Docker or binary, master key, adding documents, searchable and filterable attributes, typo tolerance, API keys, HTTPS, backups.
MySQL Slow Query Log: Enable It and Find Slow Queries
Enable the MySQL or MariaDB slow query log, pick long_query_time, analyse it with mysqldumpslow and pt-query-digest, and fix what you find.
MongoDB vs MySQL: Document or Relational Database?
Compare MongoDB and MySQL on data model, schema, queries and joins, transactions, scaling and operations, and when JSON columns are enough.
PostgreSQL VACUUM and Autovacuum Explained
Why PostgreSQL needs VACUUM, how autovacuum works, finding bloat, tuning autovacuum per table, VACUUM FULL vs pg_repack, wraparound protection.
Allow Remote Access to MySQL or MariaDB (Securely)
Enable remote MySQL or MariaDB connections safely: bind-address, user@host accounts, firewall rules for one IP, TLS, SSH tunnels and common errors.
DuckDB: Fast Analytics on CSV, Parquet and Logs Without a Server
Use DuckDB for fast analytics without a server: query CSV, JSON and Parquet with SQL, analyze Nginx logs, attach PostgreSQL, export results, Python examples.