Topic
RedisIntermediateRedis and Memcached compared by mechanism: threading, slab vs allocator memory, expiry and eviction, persistence, clustering, meta commands, operations and licensing, with a recommendation.
#caching#internals#nosql
Explains by mechanism where InnoDB or PostgreSQL does less work for lookups, updates, joins, connections and replication, then shows how to benchmark your own workload with pgbench and sysbench.
#internals#mvcc#performance
PostgreSQLIntermediateA reference comparison of PostgreSQL and MySQL: storage and MVCC, isolation defaults, DDL, data types, indexes, replication, licensing and tooling, with a decision summary.
#indexing#internals#replication
SQLiteAdvancedHow the -wal and -shm files, read marks and checkpoints work, why a WAL grows without bound, and how to set checkpointing, journal_size_limit and synchronous.
#concurrency#configuration#internals
SQLiteIntermediateWhat SQLITE_BUSY means, where it is returned in rollback-journal and WAL mode, why a timeout sometimes does nothing, the extended codes, and how to find who holds the lock.
#concurrency#internals#locking
SQL ServerBeginnerIt's caching by design, not a leak, but the default limit is 'everything'. How to set max server memory and tell real memory pressure from a full buffer pool.
#configuration#internals#performance
PostgreSQLIntermediateMVCC means Postgres doesn't store a row count. Make exact counts cheaper, get instant estimates from the planner, and keep exact counters when you really need them.
#internals#mvcc#performance
PostgreSQLAdvancedEvery UPDATE in PostgreSQL leaves a dead row behind. Here's how MVCC works under the hood, what VACUUM cleans up, and how to keep autovacuum ahead of your workload.
#concurrency#internals#maintenance
MySQLIntermediateIn MySQL's InnoDB, the table is the primary key index. That single fact shapes insert speed, index size and how you should pick primary keys.
#indexing#internals#schema-design
SQLiteIntermediateSQLite can serve real production traffic. Here's how WAL mode changes concurrency, which PRAGMAs to set, and where the limits are.
#concurrency#internals#performance
