Postgres FM

Hosted by Nikolay Samokhvalov and Michael Christofides

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181

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May 2026

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About the show

A weekly podcast about all things PostgreSQL

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May 29, 2026Episode 18146 min

autovacuum

Nik and Michael discuss autovacuum, including what it does, and the basics of why and how to tune it. Here are some links to things they mentioned: autovacuum https://www.postgresql.org/docs/current/routine-vacuuming.html#AUTOVACUUMautovacuum configuration parameters https://www.postgresql.org/docs/current/runtime-config-vacuum.html#RUNTIME-CONFIG-AUTOVACUUMWhat’s Missing in Postgres? (our episode with Bruce Momjian) https://postgres.fm/episodes/what-s-missing-in-postgrespg_squeeze (our episode with Antonín Houska) https://postgres.fm/episodes/pg_squeezeMy queries to monitor autovacuum (post by Laurenz Albe) https://www.cybertec-postgresql.com/en/monitor-autovacuum-my-queries/Autovacuum Tuning Basics (post by Tomas Vondra, originally for 2nd Quadrant blog) https://www.enterprisedb.com/blog/autovacuum-tuning-basicsZero autovacuum_vacuum_cost_delay, Write Storms, and You (post by Jeremy Schneider) https://ardentperf.com/2026/04/12/zero-autovacuum_cost_delay-write-storms-and-you/Our episode on long-running transactions / xmin horizon https://postgres.fm/episodes/long-running-transactions~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

May 15, 2026Episode 18043 min

pg_flight_recorder

Nik and Michael are joined by David Ventimiglia to discuss pg_flight_recorder, a new tool he created for monitoring a Postgres database from within. Here are some links to things they mentioned: David Ventimiglia https://postgres.fm/people/david-ventimigliapg_flight_recorder https://github.com/dventimisupabase/pg_flight_recorderSupabase https://supabase.compg_wait_sampling https://github.com/postgrespro/pg_wait_samplingpg_ash https://github.com/NikolayS/pg_ashpg_cron https://github.com/citusdata/pg_cronpg_tle https://github.com/aws/pg_tle~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

May 8, 2026Episode 17947 min

PgQue

Nik and Michael discuss Nik's new project PgQue, a descendent of Skype's PgQ, for running queue-like workloads in Postgres. Here are some links to things they mentioned: Our first episode on Queues in Postgres https://postgres.fm/episodes/queues-in-postgresPgQue https://github.com/NikolayS/pgqueHN discussion https://news.ycombinator.com/item?id=47817349PgQ https://github.com/pgq/pgqpgmq https://github.com/pgmq/pgmqRiver https://riverqueue.comKeeping a Postgres queue healthy (blog post by Simeon Griggs / PlanetScale) https://planetscale.com/blog/keeping-a-postgres-queue-healthyPostgres Job Queues & Failure By MVCC (blog post by Brandur) https://brandur.org/postgres-queuesMy queries to monitor autovacuum (blog post by Laurenz Albe) https://www.cybertec-postgresql.com/en/monitor-autovacuum-my-queries/SELECT FOR UPDATE considered harmful (blog post by Laurenz Albe) https://www.cybertec-postgresql.com/en/select-for-update-considered-harmful-postgresql/Christophe Pettus blog post https://thebuild.com/blog/2026/05/03/pgque-two-snapshots-and-a-diffOur episode on pg_ash https://postgres.fm/episodes/pg_ashRediscovering PgQ (Alexander Kukushkin slides) https://speakerdeck.com/cyberdemn/rediscovering-pgqTick frequency tuning https://github.com/NikolayS/PgQue/blob/main/docs/tick-frequency.md~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

April 24, 2026Episode 17844 min

pg_wait_tracer

Nik and Michael are joined by Dmitry Fomin to discuss his new tool pg_wait_tracer, as well as changes that could be made to core to allow wait event tracing with lower overhead, and on managed services. Here are some links to things they mentioned: Dmitry Fomin https://postgres.fm/people/dmitry-fominpg_wait_tracer https://github.com/DmitryNFomin/pg_wait_tracerpg_wait_sampling https://github.com/postgrespro/pg_wait_samplingpg_10046 https://github.com/DmitryNFomin/pg_10046Jeremy Schneider reply on LinkedIn https://www.linkedin.com/feed/update/urn:li:activity:7414966981847748608RDS for PostgreSQL wait event docs https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/PostgreSQL.Tuning.concepts.summary.htmlCustom wait events for extensions (added in PostgreSQL 17) https://www.postgresql.org/docs/current/xfunc-c.html#XFUNC-ADDIN-WAIT-EVENTSHacking Postgres with Dmitry, Kirk, and Nik (Part 1) https://www.youtube.com/watch?v=3Gtuc2lnnsEHacking Postgres with Dmitry, Kirk, and Nik (Part 2) https://www.youtube.com/watch?v=6kqpjnpl5GcTanel Poder https://tanelpoder.com/about/USDT static tracepoints for wait event tracing (proof of concept by Nik) https://github.com/NikolayS/postgres/pull/18Add wait_event_timing: Oracle-style wait event instrumentation (patch by Dmitry) https://github.com/DmitryNFomin/postgres/pull/1PgQue benchmarks https://github.com/NikolayS/pgque/blob/main/docs/benchmarks.mdThe Art of Computer Systems Performance Analysis Techniques for Experimental Design, Measurement, Simulation and Modeling (by Raj K. Jain) https://www.researchgate.net/publication/259310412_The_Art_of_Computer_Systems_Performance_Analysis_Techniques_For_Experimental_Design_Measurement_Simulation_and_Modeling_NY_WileyPerformance modeling and design of computer systems queueing theory in action (by Prof. Mor Harchol-Balter) https://www.cs.cmu.edu/~harchol/PerformanceModeling/book.htmlOracle Performance Firefighting (by Craig_Shallahamer) https://www.abebooks.co.uk/9780984102303/Oracle-Performance-Firefighting-Craig-Shallahamer-0984102302/plpProcess Mining: Data Science in Action (by Wil van der Aalst) https://link.springer.com/book/10.1007/978-3-662-49851-4~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

April 17, 2026Episode 17745 min

Schema design checklist

Nik and Michael discuss a list of things to check when designing new schema in Postgres. Here are some links to things they mentioned:Use BIGINT in Postgres (blog post by Ryan Lambert) https://blog.rustprooflabs.com/2021/06/postgres-bigint-by-defaultPostgres 18 and UUIDv7 (blog post by Gwen Shapira) https://www.thenile.dev/blog/uuidv7How to use UUID (how-to guide by Nik) https://postgres.ai/docs/postgres-howtos/schema-design/data-types/how-to-use-uuidOur episode on constraints https://postgres.fm/episodes/constraintsOur episode on NULLs https://postgres.fm/episodes/nulls-the-good-the-bad-the-ugly-and-the-unknownMultiXact member space exhaustion episode (with Metronome) https://postgres.fm/episodes/multixact-member-space-exhaustionOur Column Tetris episode https://postgres.fm/episodes/column-tetrisSaving Space Basically for Free (blog post by James Coleman from Braintree) https://medium.com/paypal-tech/postgresql-at-scale-saving-space-basically-for-free-d94483d9ed9aOver-indexing episode https://postgres.fm/episodes/over-indexingUnder-indexing episode https://postgres.fm/episodes/under-indexingGadget's use of Postgres https://postgres.fm/episodes/gadgets-use-of-postgresPartitioning episode https://postgres.fm/episodes/partitioningRLS vs performance episode https://postgres.fm/episodes/rls-vs-performance~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

April 3, 2026Episode 17643 min

What’s Missing in Postgres?

Nik and Michael are joined by Bruce Momjian to discuss his new talk "What’s Missing in Postgres?" Here are some links to things they mentioned: Bruce Momjian https://postgres.fm/people/bruce-momjianEDB https://www.enterprisedb.comWhat’s Missing in Postgres? (Bruce’s slides) https://momjian.us/main/writings/pgsql/missing.pdfThe Wonderful World of WAL (Bruce’s slides) https://momjian.us/main/writings/pgsql/wal.pdfGetting started with benchmarking (our episode with Melanie Plageman) https://postgres.fm/episodes/getting-started-with-benchmarkingMyths and Truths about Synchronous Replication in Postgres (talk by Alexander Kukushkin) https://www.youtube.com/watch?v=PFn9qRGzTMcThe Future of Postgres Sharding (Bruce’s slides) https://momjian.us/main/writings/pgsql/sharding.pdfMultiXact member space exhaustion https://postgres.fm/episodes/multixact-member-space-exhaustion~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

March 27, 2026Episode 17548 min

Long-running transactions

Nik and Michael discuss long-running transactions, including when they're harmless, when they cause issues, and how to mitigate those issues. Here are some links to things they mentioned: transaction_timeout https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-TRANSACTION-TIMEOUTOur episode on transaction_timeout https://postgres.fm/episodes/transaction_timeoutOur episode on slow queries (which was also our first ever episode!) https://postgres.fm/episodes/slow-queries-and-slow-transactionsOur episode on locks https://postgres.fm/episodes/lockslock_timeout https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-LOCK-TIMEOUTTransaction Isolation levels https://www.postgresql.org/docs/current/transaction-iso.htmlpg_current_xact_id_if_assigned() https://pgpedia.info/p/pg_current_xact_id_if_assigned.htmlMonitor xmin horizon to prevent XID/MultiXID wraparound and high bloat (how-to guide by Nik) https://postgres.ai/docs/postgres-howtos/performance-optimization/monitoring/how-to-monitor-xmin-horizonidle_replication_slot_timeout https://www.postgresql.org/docs/current/runtime-config-replication.html#GUC-IDLE-REPLICATION-SLOT-TIMEOUTPREPARE TRANSACTION https://www.postgresql.org/docs/current/sql-prepare-transaction.htmllog_autovacuum_min_duration https://www.postgresql.org/docs/devel/runtime-config-logging.html#GUC-LOG-AUTOVACUUM-MIN-DURATIONPostgreSQL Subtransactions Considered Harmful (blog post by Nikolay) https://postgres.ai/blog/20210831-postgresql-subtransactions-considered-harmfulstatement_timeout https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-STATEMENT-TIMEOUTidle_in_transaction_session_timeout https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-IDLE-IN-TRANSACTION-SESSION-TIMEOUTlock_timeout https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-LOCK-TIMEOUT~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

March 13, 2026Episode 17453 min

PostGIS

Nik and Michael are joined by Regina Obe and Paul Ramsey to discuss PostGIS. Here are some links to things they mentioned:Regina Obe https://postgres.fm/people/regina-obePaul Ramsey https://postgres.fm/people/paul-ramseyPostGIS https://postgis.netMobilityDB https://github.com/MobilityDB/MobilityDBpgRouting https://github.com/pgRouting/pgroutingGoogle BigQuery GIS public alpha blog post https://cloud.google.com/blog/products/data-analytics/whats-happening-bigquery-integrated-machine-learning-maps-and-morePostGIS Day 2025 talk recordings https://www.youtube.com/watch?v=wuNO_cW2g-0&list=PLavJpcg8cl1EkQWoCbczsOjFTe-SHg_8mpg_lake https://github.com/Snowflake-Labs/pg_lakeGeoParquet https://geoparquet.orgST_DWithin https://postgis.net/docs/ST_DWithin.htmlPostgres JSONB Columns and TOAST: A Performance Guide https://www.snowflake.com/en/engineering-blog/postgres-jsonb-columns-and-toastFOSS4G https://foss4g.orgOpenStreetMap https://www.openstreetmap.orgPgDay Boston https://2026.pgdayboston.orgSKILL.md file https://github.com/postgis/postgis/blob/68dde711039986b47eb62feda45bb24b13b0ea37/doc/SKILL.mdProduction query plans without production data (blog post by Radim Marek) https://boringsql.com/posts/portable-statsPostgreSQL: Up and Running, 4th Edition (by Regina Obe, Leo Hsu) https://www.oreilly.com/library/view/postgresql-up-and/9798341660885~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

March 6, 2026Episode 17342 min

Plan flips

Nik and Michael discuss query plan flips in Postgres — what they are, some causes, mitigations, longer term solutions, and the recent outage at Clerk. Here are some links to things they mentioned: Recent postmortem from Clerk https://clerk.com/blog/2026-02-19-system-outage-postmortemThe real cost of random I/O (blog post by Tomas Vondra) https://vondra.me/posts/the-real-cost-of-random-ioautovacuum_analyze_scale_factor https://www.postgresql.org/docs/current/runtime-config-vacuum.html#GUC-AUTOVACUUM-ANALYZE-SCALE-FACTORdefault_statistics_target https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-DEFAULT-STATISTICS-TARGETpg_hint_plan https://github.com/ossc-db/pg_hint_planAurora PostgreSQL query plan management https://docs.aws.amazon.comAmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.Optimize.Start.htmlpg_stat_plans https://github.com/pganalyze/pg_stat_planspg_plan_alternatives https://jnidzwetzki.github.io/2026/03/04/pg-plan-alternatives.htmlWaiting for Postgres 19: Better Planner Hints with Path Generation Strategies https://pganalyze.com/blog/5mins-postgres-19-better-planner-hints~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

February 20, 2026Episode 17232 min

pg_ash

Nik and Michael discuss pg_ash — a new tool (not extension!) from Nik that samples and stores wait events from pg_stat_activity. Here are some links to things they mentioned: pg_ash https://github.com/NikolayS/pg_ashpg_wait_sampling https://github.com/postgrespro/pg_wait_samplingAmazon RDS performance insights https://aws.amazon.com/rds/performance-insightsOur episode on wait events https://postgres.fm/episodes/wait-eventspg-flight-recorder https://github.com/dventimisupabase/pg-flight-recorderpg_profile https://github.com/zubkov-andrei/pg_profilepg_cron https://github.com/citusdata/pg_cron~~~What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork