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.
Galera's multi-primary promise has a footnote: write the same row on two nodes and one transaction dies at COMMIT. How certification conflicts work, what the counters say, and how to design them out.
The default autovacuum cost settings throttle vacuum to a pace modern hardware laughs at. On big write-heavy tables, that means dead tuples win. Here is how to retune.
MariaDB and MySQL forked over a decade ago and the operational differences are now real: incompatible GTID formats, JSON as a LONGTEXT alias, system-versioned tables, a bundled thread pool, and replication gotchas.
A single unique violation on a logical replication subscriber can stall the stream and fill the publisher's disk with retained WAL. Here is how conflicts happen and how to recover.
ColumnStore gives MariaDB a columnar, distributed analytics engine alongside InnoDB. Here is when columnar genuinely wins, how the architecture works, and the honest limits nobody puts in the sales deck.
One runaway query or one forgotten BEGIN can take a production PostgreSQL database down. Three timeout settings are the difference between an incident and a non-event.
MariaDB and MySQL share ancestry but their optimizers have diverged for over a decade. Here is what actually differs: optimizer_switch defaults, persistent histograms, engine-independent statistics, and a migration playbook.
A BRIN index can be a thousand times smaller than the btree it replaces, or it can sit there doing nothing while costing write overhead. Physical correlation makes the difference.
Aria is the crash-safe successor to MyISAM that MariaDB uses under the hood for internal temp tables and its own system tables. Here is how it works, how it differs from InnoDB, and why operators should care.
PostgreSQL compresses big values silently, and since version 14 you get to pick the codec. Here is how to find toasted columns, weigh pglz against lz4, and switch without surprises.