Notes for the problems that show up after launch: bad plans, awkward migrations, index debt, vacuum pressure, replica lag, and the small decisions that keep PostgreSQL, MySQL, MariaDB, and SQL Server easier to operate.
Find the queries dragging your Postgres down, read their plans, and fix them in order of impact.
Read the guide →Which indexes to add, which to drop, and how to spot redundant index debt before it costs you writes.
Read the guide →How autovacuum works, when it falls behind, and how to keep bloat from eating your storage and your buffer cache.
Read the guide →Sizing pools, PgBouncer modes, and how to stop idle-in-transaction sessions from exhausting max_connections.
Read the guide →Track lag, WAL throughput, and replication slots before they turn into stale reads or a full disk.
Read the guide →
Backups, restores, PITR, archive gaps, and recovery drills for PostgreSQL.
AWS RDS, Azure Database for PostgreSQL, Google Cloud SQL, AlloyDB, and managed PostgreSQL monitoring notes.
Connection storms, pool saturation, PgBouncer behavior, and max_connections pressure.
CPU, memory, disk, temp files, checkpoints, buffers, and workload pressure.
Index design, index debt, reindexing, constraint indexes, and evidence-driven DDL.
Lock waits, deadlocks, blocking chains, idle transactions, and transaction hygiene.
Galera clustering, InnoDB and Aria internals, replication, optimizer behavior, and MariaDB operations notes.
InnoDB internals, replication, locking, query performance, and MySQL operations notes.
HNSW, IVFFlat, recall, embedding search, and production RAG performance notes.
Replica lag, WAL growth, failover readiness, hot standby behavior, and replication slots.
Query plans, EXPLAIN ANALYZE, planner regressions, pagination, joins, and statistics.
Wait statistics, tempdb, Query Store, Always On availability groups, and SQL Server operations notes.
Autovacuum, dead tuples, bloat, wraparound, MVCC, freeze age, and visibility.
Spider turns one logical MariaDB table into partitions that live on remote servers. Here is how to set it up, where it beats app-level sharding, and the limits nobody mentions.
MariaDB has real sequence objects; MySQL never got them. They shine for shared id spaces and ids known before the insert, and they are a waste of a round trip for a single hot table.
A deploy 'removed' three hundred analysts' access without revoking anything — the role was granted but never active at login. MariaDB roles done right: SET DEFAULT ROLE, PUBLIC in 10.11, and auditing effective privileges.
Async replication, semi-sync, and Galera are not versions of the same feature — they are different trades in latency, consistency, and operations. A field guide to choosing between them on MariaDB.
The query cache lives on in MariaDB long after MySQL deleted it, and on a busy many-core server it is often the top contention point. Here is how to prove it with counters and what to run instead.
Optimistic parallel replication bets that your transactions will not conflict and pays for the bet in rollbacks. Here is how the five slave_parallel_mode modes differ, when the bet wins, and how to measure real lag.
MyRocks swaps InnoDB's B+tree for RocksDB's LSM tree, trading slower range scans for far cheaper writes and better compression. Here is when that trade is worth making — and when it is not.
The MySQL-to-MariaDB path is a logical migration, not an in-place upgrade. What breaks — auth plugins, JSON semantics, GTID, collations — and the checklist to run before you switch.
Every shared MariaDB box eventually meets the query that should never have been allowed to run for six hours. max_statement_time is the built-in kill switch — here is how to scope it, what it actually kills, and why it will…
The nightly backup nobody restores is a rumor. A field guide to mariabackup: full and incremental chains, prepare discipline, encryption and Galera SST, the redo log-copy race, and the restore drill that proves it all.