A read-only preset, like block_size — SHOW data_checksums tells you whether the cluster has page checksums, and that’s the only interaction the GUC offers. But unlike block_size, this one has a...

The planner assumes cursors fetch only 10% of results by default. If you're actually reading them all, that fast-start bias could be killing your performance.

PostgreSQL 16 overhauled role management to tame the near-superuser power of CREATEROLE.

cpu_tuple_cost, cpu_index_tuple_cost, and cpu_operator_cost are three of the constants the planner uses to price a query, and the single most useful thing to know about all three is that you...

Skip partition scanning with constraint_exclusion, PostgreSQL's old pruning trick.

PostgreSQL's `config_file` parameter creates a bootstrap paradox: it tells the server where to find its configuration, but lives on the command line only—never…

PostgreSQL 14 unified query-id computation across all subsystems, but defaulting to always-on would tax every backend.

PostgreSQL 17 made SLRU buffer pools configurable for the first time.

Tune `commit_delay` to batch WAL flushes and trade latency for throughput—but only if `pg_test_fsync` proves sync time is your bottleneck.

cluster_name looks like a cosmetic label for process listings, but on a standby it silently becomes the name your primary uses to verify synchronous…

`client_min_messages` controls what your session sees, not what the server logs—a confusion that spawns most of its trouble.

PostgreSQL validates function bodies at creation time by default, catching syntax errors early.

PostgreSQL's `bytea_output` parameter controls how binary data is formatted when sent to clients: the modern `hex` format (default since 9.0) or the legacy…

A parameter you cannot change. block_size lives in the “Preset Options” section of the docs, alongside its read-only cousins like data_checksums, wal_block_size, and server_version. It reports the...

These two parameters close out the bgwriter cluster. Together with bgwriter_delay, they govern how the background writer decides what to write each round, and they are where the actual leverage...

The B cluster shifts gears: from one-off oddities to the background writer parameters, which span four GUCs. We do the first two as a pair because bgwriter_delay introduces the process at all, and...

Debug PostgreSQL errors by capturing C-level stack traces for specific internal functions.

PostgreSQL's complicated relationship with the Linux page cache spawns four GUCs to manage writeback—and backend_flush_after is the conservative one.

PostgreSQL 18 splits autovacuum configuration to finally let you tune worker concurrency without restarting.

autovacuum_work_mem sets the maximum memory each autovacuum worker may use for tracking dead tuple identifiers (TIDs) during a vacuum. Default is -1, which means “inherit from...