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-TIMEOUT Our episode on transaction_timeout https://postgres.fm/episodes/transaction_timeout Our episode on slow queries (which was also our first ever episode!) https://postgres.fm/episodes/slow-queries-and-slow-transactions Our episode on locks https://postgres.fm/episodes/locks lock_timeout https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-LOCK-TIMEOUT Transaction Isolation levels https://www.postgresql.org/docs/current/transaction-iso.html pg_current_xact_id_if_assigned() https://pgpedia.info/p/pg_current_xact_id_if_assigned.html Monitor 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-horizon idle_replication_slot_timeout https://www.postgresql.org/docs/current/runtime-config-replication.html#GUC-IDLE-REPLICATION-SLOT-TIMEOUT PREPARE TRANSACTION https://www.postgresql.org/docs/current/sql-prepare-transaction.html log_autovacuum_min_duration https://www.postgresql.org/docs/devel/runtime-config-logging.html#GUC-LOG-AUTOVACUUM-MIN-DURATION PostgreSQL Subtransactions Considered Harmful (blog post by Nikolay) https://postgres.ai/blog/20210831-postgresql-subtransactions-considered-harmful statement_timeout https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-STATEMENT-TIMEOUT idle_in_transaction_session_timeout https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-IDLE-IN-TRANSACTION-SESSION-TIMEOUT lock_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 pgMustard Nikolay Samokhvalov, founder of Postgres.ai With credit to: Jessie Draws for the elephant artwork