5 min read
Postgres Checkpoint Tuning: The Latency Spike Nobody Sees Coming
Checkpoint problems show up as periodic latency spikes. The work is smoothing writes, sizing WAL, and proving checkpoints are the thing users feel.
Database Field Notes
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.
Featured Guides
Slow query optimization
Find the queries dragging your Postgres down, read their plans, and fix them in order of impact.
Read the guide →Index optimization
Which indexes to add, which to drop, and how to spot redundant index debt before it costs you writes.
Read the guide →Vacuum guide
How autovacuum works, when it falls behind, and how to keep bloat from eating your storage and your buffer cache.
Read the guide →Connection pooling
Sizing pools, PgBouncer modes, and how to stop idle-in-transaction sessions from exhausting max_connections.
Read the guide →Replication monitoring
Track lag, WAL throughput, and replication slots before they turn into stale reads or a full disk.
Read the guide →Browse by Topic
Backups and Durability
9 articlesBackups, restores, PITR, archive gaps, and recovery drills for PostgreSQL.
Cloud Providers
5 articlesAWS RDS, Azure Database for PostgreSQL, Google Cloud SQL, AlloyDB, and managed PostgreSQL monitoring notes.
Connections and Pooling
10 articlesConnection storms, pool saturation, PgBouncer behavior, and max_connections pressure.
CPU, Memory, and I/O
17 articlesCPU, memory, disk, temp files, checkpoints, buffers, and workload pressure.
Indexes
37 articlesIndex design, index debt, reindexing, constraint indexes, and evidence-driven DDL.
Locks and Transactions
22 articlesLock waits, deadlocks, blocking chains, idle transactions, and transaction hygiene.
MariaDB
56 articlesGalera clustering, InnoDB and Aria internals, replication, optimizer behavior, and MariaDB operations notes.
MySQL
107 articlesInnoDB internals, replication, locking, query performance, and MySQL operations notes.
pgvector and RAG
15 articlesHNSW, IVFFlat, recall, embedding search, and production RAG performance notes.
Replication and WAL
28 articlesReplica lag, WAL growth, failover readiness, hot standby behavior, and replication slots.
Slow Queries
38 articlesQuery plans, EXPLAIN ANALYZE, planner regressions, pagination, joins, and statistics.
SQL Server
47 articlesWait statistics, tempdb, Query Store, Always On availability groups, and SQL Server operations notes.
Vacuum and Bloat
16 articlesAutovacuum, dead tuples, bloat, wraparound, MVCC, freeze age, and visibility.
Latest Field Notes
5 min read
Time-Series Data in Postgres: Honest Tradeoffs Before You Reach for TimescaleDB
Postgres handles time-series data better than people assume. The decision to add a specialized extension should come from observed limits, not preemptive optimization.
5 min read
Incremental Aggregation in Postgres: When Materialized Views Are Not Enough
Postgres materialized views refresh a result set; they do not give you automatic incremental aggregation. For high-churn dashboards, you need deltas, watermarks, and late-data rules.
5 min read
Postgres High CPU: Where the Cycles Actually Go
When Postgres CPU is high, the question is not whether the server is fast enough. It is which queries are using the cycles and whether they should be.
6 min read
Postgres High I/O: Diagnosing Where Disk Goes Wrong
High I/O is not a storage verdict. It is a workload question: which query, table, index, vacuum, checkpoint, or spill is reading and writing the bytes?
5 min read
Postgres Memory Pressure: Diagnosing OOMs and the Settings That Prevent Them
A Postgres OOM kill is one of the few crashes that is almost always preventable. The pattern is consistent enough to have a checklist.
5 min read
Temporary Files in Postgres: When Queries Spill to Disk and Why
Temp files are hidden disk work. They explain slow sorts, hash joins, and aggregations that look fine until work_mem runs out under real concurrency.
5 min read
When the Planner is Wrong: Fixing Bad Row Estimates in Postgres
Bad plans usually start with bad row estimates. Fix the first wrong estimate and the rest of the plan often stops looking mysterious.
4 min read
Slow Inserts in Postgres: It’s Almost Always One of Three Things
Slow inserts are rarely just inserts. They are usually index maintenance, constraint and trigger work, WAL/checkpoint pressure, or a transaction pattern that makes every row pay retail.
4 min read
Slow Deletes in Postgres: It’s Almost Never the Delete Itself
Slow deletes usually come from the work around the row: foreign keys, triggers, indexes, WAL, vacuum debt, and transaction size. The fix starts by finding what each deleted row has to pay for.