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.
InnoDB and PostgreSQL pay for UPDATEs in completely different currencies. Here is how secondary index maintenance, change buffering, HOT updates, and fillfactor actually behave under an update-heavy workload.
InnoDB puts almost everything in one big buffer pool, while PostgreSQL splits caching between shared_buffers and the OS page cache. Here is how the two models differ and how to monitor each honestly.
Triggers or binlog streaming? Field notes from running both gh-ost and pt-online-schema-change in production: cut-over risk, throttling behavior, foreign key walls, and when you need neither.
MySQL offers VIRTUAL and STORED generated columns; PostgreSQL 16 and 17 offer stored ones plus expression indexes. Field notes on mapping one model to the other when you migrate.
MySQL's history made foreign keys optional culture; PostgreSQL's made them default culture. Here is how to migrate FK-less data honestly: NOT VALID, deferred constraints, and deliberate ON DELETE.
COUNT(*) is slow on big tables in both InnoDB and PostgreSQL, for related but different MVCC reasons. Here are the honest options: index-only counting, estimates, and counter tables.
MySQL hides case behind collations and lower_case_table_names; PostgreSQL makes you choose explicitly. Here are the bugs this difference causes in migrations, and the three fixes that work.
Most MySQL-vs-PostgreSQL benchmarks are decided before the first query runs, by defaults, durability settings, and tool choice. Here is how to run a comparison that actually predicts your production behavior.
Both Aurora flavors share the same storage layer and carry very different databases on top. Here is how I compare them: feature deltas, the extension ecosystem, performance tests you should run yourself, and migration gravity.
Same procedure, two seconds for one tenant, thirty-second timeouts for another. How to prove parameter sniffing with plan variance, and the fix toolkit ranked from better indexes to 2022's Parameter Sensitive Plan optimization.