ClickHouse columnar storage, the MergeTree engine family, primary key vs sorting key, materialized views for pre-aggregation, query profiling with EXPLAIN, replication with ClickHouse Keeper, distributed tables for sharding, and when to choose ClickHouse over PostgreSQL.
Database
-
ClickHouse for Analytics Workloads -
PgBouncer and PostgreSQL Connection Pooling Why PostgreSQL's process-per-connection model requires a connection pooler, PgBouncer session vs transaction vs statement pooling modes and their tradeoffs, pgbouncer.ini configuration, monitoring with SHOW commands, and a comparison of PgBouncer, Pgpool-II, and Supavisor.
-
PostgreSQL Internals and Tuning How PostgreSQL works under the hood: MVCC for non-blocking reads, heap and TOAST storage, WAL for durability and replication, VACUUM and autovacuum mechanics, EXPLAIN ANALYZE output explained, index types, pg_stat_statements for query analysis, and key postgresql.conf tuning parameters.
-
PostgreSQL Replication and High Availability PostgreSQL streaming replication setup, synchronous vs asynchronous tradeoffs, logical replication for selective sync and zero-downtime upgrades, pg_basebackup for standby creation, Patroni with etcd for automatic failover, pg_rewind for rejoining a former primary, and monitoring replication lag.
-
Redis Architecture and Persistence Redis data structures and their use cases, RDB vs AOF vs hybrid persistence, Redis Sentinel for high availability, Redis Cluster for horizontal scaling with hash slots, eviction policies, diagnostic commands, and an honest look at when Redis is the right tool.
-
Secrets Rotation Without Downtime: Rotating Credentials in Live Systems Patterns for rotating database passwords, API keys, and TLS certificates in production systems with zero application restarts — covering the dual-credential pattern, dynamic secrets with Vault, automated certificate rotation, and the operational runbook for each scenario.
-
Database Design Fundamentals Principles for designing database schemas that scale and perform.