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.
A 64-core, 512GB RAM SQL Server instance was stalling at 25% CPU with hundreds of worker threads blocked on PAGELATCH_UP in database 2. Here is the architecture of TempDB allocation bottlenecks and how to resolve them.
A billing stored procedure that normally completes in 4ms suddenly took 14 seconds per call, pinning SQL Server CPU at 98%. Here is how parameter sniffing poisons Query Store and how to remediate it in production.
An analytics engineer hooked up a Debezium CDC pipeline on staging, pointed it to production for a test, and shut down their laptop. Four hours later, 1.3TB of WAL filled the disk. Here is how replication slots retain WAL and…
Partitioned a 120-million-row events table into 365 daily partitions and queries got slower? Here is the deep architecture of static vs run-time partition pruning, prepared statements, and lock table explosion.
At 2:15 AM on a Black Friday rollout, our Kubernetes cluster spawned 5,400 direct connections to PostgreSQL. CPU hit 100% with zero query throughput. Here is the high-level architecture of why Postgres chokes on connection volume and how connection pooling…
Migrated to 80,000 IOPS NVMe drives and still getting periodic latency spikes? Here is why PostgreSQL checkpoints cause latency sawteeth and how to tune max_wal_size, completion targets, and Linux dirty page writeback.
Enabled semi-synchronous replication to guarantee zero data loss and watched commit latency quadruple? Here is the deep architecture of MySQL binary log commits, AFTER_SYNC vs AFTER_COMMIT, and cross-AZ network latency.
During a high-concurrency inventory reservation event, MySQL CPU hit 100% with lock wait timeouts everywhere. Here is the deep architectural mechanics of InnoDB next-key locks, gap locks, and deadlock detection cascades.
In a 3-node MariaDB Galera cluster, an automated backup on Node 3 caused write throughput across the whole cluster to collapse from 2,800 to 12 QPS. Here is how Galera flow control works and how to design resilient replication topologies.
A billing reconciliation service migrated from SQL Server to PostgreSQL and began double-crediting customer accounts under Read Committed. Here is the deep architectural truth of transaction isolation anomalies across engines.