## Incremental Update: Report Oldest Xmin Source When Autovacuum Cannot Remove Tuples ### Summary Limited new technical substance since the last analysis. The thread saw one bug identification by th...
# pg_rewind Does Not Rewind Diverging Timelines — May 2026 Summary ## Problem Statement Mats Kindahl discovered (via TLA+/TLC model checking) that PostgreSQL's timeline identifier (TLI) system can s...
## Incremental Update: Concrete Benchmarks, WIP Patches, and Protocol Design Discussion ### Key Developments 1. **Nathan posted concrete benchmark results at 1M scale** comparing Jelte's `CreateOne...
## Incremental Analysis: Andrey Borodin's Architectural Review Andrey Borodin provides the first substantive review of the GiST-side architecture, raising three distinct technical concerns and broade...
# Technical Analysis: Fix libxml Leaks in contrib/xml2 XPath Functions ## Core Problem The `contrib/xml2` module contains two memory leak bugs on **successful execution paths** in its XPath evaluat...
# Technical Analysis: Renaming `pg_attribute_always_inline` to a Shorter Form ## Core Problem The macro `pg_attribute_always_inline` — used to force the compiler to inline a function regardless of ...
## Incremental Update No substantive technical progress since the prior analysis. The two new messages are: 1. **Corey Huinker** provides a +1 endorsement with no new technical content beyond affirm...
# Technical Analysis: pg_stat_lock Blocker Mode Dimension ## Core Problem PostgreSQL's `pg_stat_lock` view (introduced in recent versions to provide cumulative lock wait statistics) currently aggre...
# Monthly Summary: RFC: Allow EXPLAIN to Output Page Fault / Storage I/O Information — May 2026 ## Overview This month saw the discussion mature from technical refinement into a serious viability de...
# Monthly Summary: Online Data Checksums — May 2026 ## Overview May 2026 saw continued post-commit stabilization of the online data checksums feature. The major commit had already landed, and this m...
# Technical Analysis: tablecmds.c `recurse` vs `recursing` Parameter Naming Clarity ## Core Problem PostgreSQL's `tablecmds.c` is one of the largest and most complex files in the codebase, implemen...
# Dynamic Logical Decoding Activation Without Server Restart ## Core Problem PostgreSQL's `wal_level` parameter controls how much information is written to WAL records. Setting it to `logical` enab...
# Monthly Summary: Join Statistics for the PostgreSQL Planner (May 2026) ## Overview May 2026 saw the "join statistics" patch transition from conceptual design convergence to active committer-level ...
# pg_rewind: Skip Vanished Source Files During Traversal ## Core Problem This thread identifies a potential bug in `pg_rewind`'s source directory traversal logic within `recurse_dir()`. The issue c...
# Incremental View Maintenance (IVM) for PostgreSQL — Deep Technical Analysis ## The Core Problem Materialized views in PostgreSQL are static snapshots: they must be fully recomputed via `REFRESH MA...
# Technical Analysis: UTF-8 Substring Validation Bug Report ## Core Problem The reporter encountered a situation where `substring(text, int, int)` (the SQL standard positional substring function) ra...
# Fix Race During Concurrent Logical Decoding Activation ## Background: Dynamic Logical Decoding Toggle This thread addresses a race condition in a newer PostgreSQL feature that allows logical deco...
# Technical Analysis: Reject HEADER with binary and json COPY formats by option presence ## Core Problem The thread identifies an inconsistency between PostgreSQL's documentation and implementation...
# PostgreSQL and OpenSSL 4.0.0 — May 2026 Summary ## Overview OpenSSL 4.0.0 (GA April 2026) introduced return-value constification on APIs used by PostgreSQL's TLS layer (`libpq`, `contrib/sslinfo`)...
# Monthly Summary: Fix ProcKill lock-group vs procLatch recycle race (May 2026) ## Overview This thread addresses a genuine concurrency bug in `ProcKill()` that has existed since PostgreSQL 9.6 (whe...
## Incremental Update: Reproducer Patch Fix and Confirmation This round contains only two messages dealing with reproducing the issue — no new technical insights into the root cause or proposed fixes...
## Incremental Update: v2 Patch Unifies the Full Bug Class ### Key Development Richard (guofenglinux@gmail.com) has posted a **v2 patch** that significantly expands the scope of the fix from the ori...
## Incremental Update: Fix Bug of CHECK Constraint Enforceability Recursion ### Summary of New Developments The thread has progressed from Jian He's simple v1 patch (reject all enforceability chang...
# Fix safe_wal_size for Slots Without restart_lsn ## Core Problem The `pg_replication_slots` system view exposes a `safe_wal_size` column that indicates how much WAL can be written before a replica...
## Incremental Update: v13 Patchset — Switch Back to TEXT Format with Refactored Escaping ### Key Change: CSV → TEXT format reversal, with code deduplication Matheus posted a new patchset (v13) that...
## Update: Patch Committed Andrew Dunstan pushed the patch on 2026-05-30. No further technical discussion accompanied the commit — just a brief confirmation message ("pushed."). This closes the open ...
# Autovacuum Launcher Crash: Assert in pgstat_count_io_op (IOOP_EXTEND on pg_database's VM) ## Technical Problem This thread reports a crash in the autovacuum launcher triggered by an assertion fail...
# Analysis: First Draft of PG 19 Release Notes — Role/Function Miscategorization Fix ## Core Problem The PostgreSQL 19 release notes contained an inaccuracy in describing a security/privilege enhan...
# Unify Parallel Worker Handling for Index Builds and Instrumentation ## Core Problem PostgreSQL's parallel index build infrastructure has accumulated significant code duplication across different ...
# Monthly Summary: Replace `txid_current()` with `pg_current_xact_id()` — May 2026 ## Overview This thread addresses replacing deprecated `txid_current()` calls in PostgreSQL's own test suite with t...
# Make Memory Checking / Sanitizing Infrastructure Better ## Core Problem PostgreSQL's internal memory management system (aset.c, slab.c, generation.c) includes debug-mode instrumentation to detect...
# Monthly Summary: Support EXCEPT for ALL SEQUENCES / TABLES IN SCHEMA Publications — May 2026 ## Overview This thread tracks two parallel extensions to PostgreSQL's logical replication publication ...
# Technical Analysis: REFRESH MATERIALIZED VIEW CONCURRENTLY + WITH NO DATA Error Checking Location ## Core Problem The thread raises a question about PostgreSQL's internal architecture regarding **...
## New in this round: Ishii flags non-ASCII character corruption in v47-0002 patch comments A single brief message from Ishii (2026-06-01) noting a cosmetic/encoding issue: the v47-0002 patch contain...
## Incremental Update: Tristan Partin's Response to Paquier's Review Tristan Partin responds to Michael Paquier's review, agreeing with some suggestions while pushing back on others. ### Key Decisio...
# CI: Skip minfree file in cores_backtrace.sh ## The Core Problem PostgreSQL's CI infrastructure uses a script (`src/tools/ci/cores_backtrace.sh`) that iterates over files in a core dump directory ...
# Technical Analysis: Make Stack Depth Check Work with ASAN's use-after-return ## Core Problem PostgreSQL implements a stack depth check (`check_stack_depth()`) to prevent unbounded recursion from c...
## Incremental Update: Commit and Follow-up Discussion ### Resolution: Patch Committed (Simplified) Robert Haas committed a simplified version of the fix. The key decisions in the simplification: 1...
# Glob Support in `extension_control_path` / `dynamic_library_path` ## Core Problem PostgreSQL 18 introduced the `extension_control_path` GUC (along with changes to `dynamic_library_path`) to allow ...
## Incremental Update: Patch v2 Addressing Non-Unique Index Handling ### Summary of New Activity Two new messages advance the discussion with a concrete patch revision. Masahiko Sawada (a committer ...
# pg_createsubscriber: Fix incorrect handling of cleanup flags — May 2026 Summary ## Overview A bug in `pg_createsubscriber`'s cleanup flag handling was identified, reviewed, and committed (with bac...
# REPACK [CONCURRENTLY] — May 2026 Monthly Summary ## Overview May 2026 was dominated by the **decision to revert db-specific snapshots** from PG19, while the core REPACK CONCURRENTLY feature remain...
# Monthly Summary: Avoid Leaking System Path from pg_available_extensions (May 2026) ## Overview This thread addresses an information disclosure bug in the `pg_available_extensions` view's `location...
# pg_recvlogical: Send Final Feedback on SIGINT/SIGTERM Exit ## Core Problem `pg_recvlogical` is PostgreSQL's command-line tool for consuming logical replication streams. It connects to a logical r...
## Commit Confirmation Tom Lane has committed the patch by folding it into commit `0f24332ae`. No further technical discussion occurred — this was a brief acknowledgment that the cleanup was incorpor...
## New Buildfarm Failure: Test Race Condition in 038_walsnd_shutdown_timeout Alexander Korotkov reports a new buildfarm failure on `tamandua` (FreeBSD) in the test `038_walsnd_shutdown_timeout.pl`, d...
# Copy-Paste Error in `hash_record_extended()` — `args[1].isnull` Not Set ## Core Problem A straightforward but potentially consequential copy-paste bug exists in `src/backend/utils/adt/rowtypes.c`...
# Monthly Summary: `ON_ERROR TABLE` — Saving COPY FROM Errors to a Table (May 2026) ## Overview May 2026 saw the most active development period for this long-running patch (originally proposed Feb 2...
# Monthly Summary: EXPLAIN ANALYZE Wait Event Reporting (May 2026) ## Overview This RFC proposes adding a new `EXPLAIN (ANALYZE, WAITS)` option that transforms PostgreSQL's wait event subsystem from...
# Fix Race in ReplicationSlotRelease for Ephemeral Slots ## Core Problem The bug exists in `ReplicationSlotRelease()`, a function responsible for releasing a backend's hold on a replication slot. T...
# Technical Analysis: Remove Obsolete tupDesc Assignment in Extended Statistics ## Core Problem This patch addresses a code hygiene issue in PostgreSQL's extended statistics subsystem, specifically...
# Monthly Summary: Rebuild CHECK Constraints After Generated Column SET EXPRESSION (May 2026) ## Overview This thread addressed a data integrity bug where `ALTER TABLE ... ALTER COLUMN ... SET EXPRE...
# Monthly Summary: Moving recovery target conflict detection out of GUC assign hooks (May 2026) ## Problem Statement PostgreSQL's five `recovery_target_*` GUCs (`recovery_target`, `recovery_target_l...
# Monthly Summary: FOR PORTION OF and GENERATED STORED Columns (May 2026) ## Overview This thread underwent a dramatic arc in May 2026: a 12-version patch series addressing stale GENERATED STORED co...
# Protocol Greasing During PostgreSQL 19 Beta — May 2026 Summary ## Overview Jacob Champion announced plans to exercise PostgreSQL's wire-protocol negotiation machinery during the 19 beta cycle usin...
# Technical Analysis: Fix typos in pqsignal.c comment ## Overview This is a minimal, comment-only patch that corrects two typographical errors in `src/port/pqsignal.c`. The patch has no functional ...
# PGConf.dev 2026 CSN Unconference Session: Technical Analysis ## The Core Problem: Commit Sequence Numbers and the Visibility/Durability Tension This thread captures the state-of-the-art thinking ...
# Technical Analysis: Statistics Import/Export for Performance Testing ## Core Problem The thread addresses a fundamental question about the PostgreSQL statistics import/export feature (introduced ...
# CREATE TABLE LIKE: INCLUDING PARAMETERS and INCLUDING TRIGGERS — May 2026 Summary ## Overview This thread advances two patches extending `CREATE TABLE ... (LIKE source INCLUDING ...)` to cover two...
# Technical Analysis: Cyclic RLS Policy / Infinite Recursion Bug in PostgreSQL ## The Core Problem Row-Level Security (RLS) policies in PostgreSQL are implemented through the query rewriter. When a...
# Monthly Summary: Release Replication Slot on Error in SQL-Callable Slot Functions (May 2026) ## Problem Statement PostgreSQL's SQL-callable replication slot functions (`pg_replication_slot_advance...
# Key Joins: A New SQL Language Feature for PostgreSQL ## Core Problem The fundamental problem addressed by this proposal is that SQL's JOIN syntax is semantically overloaded — a JOIN can serve thr...
# Analysis: DBeaver Connection Timeouts to PostgreSQL 18 on Linux ## Summary This thread is a **support request** mistakenly posted to pgsql-hackers (the development mailing list), not a development...
# Technical Analysis: postgres_fdw, dblink — Validate use_scram_passthrough Values ## Core Problem The `use_scram_passthrough` option, introduced as part of SCRAM authentication passthrough support...
# Bound Memory Usage During Manual Slot Sync Retries — May 2026 Summary ## Problem & Resolution The `pg_sync_replication_slots()` SQL function had an unbounded memory growth problem during its inter...
# Monthly Summary: Add WHERE Clause Support to REFRESH MATERIALIZED VIEW — May 2026 ## Overview This month saw significant technical maturation of the patch to add `REFRESH MATERIALIZED VIEW mv WHER...
# Monthly Summary: [PATCH] Fix LISTEN Startup Race with Direct Advancement — May 2026 ## Overview This thread identifies and fixes a correctness bug in PostgreSQL's asynchronous notification system ...
# Monthly Summary: effective_wal_level Not Decreasing After REPACK (CONCURRENTLY) — May 2026 ## Problem Statement A bug was identified in the interaction between PostgreSQL's dynamic WAL level toggl...
# Monthly Summary: Avoid calling SetMatViewPopulatedState if possible (May 2026) ## Overview A focused optimization patch to eliminate unnecessary `pg_class` catalog updates during `REFRESH MATERIAL...
# Monthly Summary: Improve pg_stat_statements Scalability — May 2026 ## Overview May 2026 saw the pg_stat_statements scalability patch evolve from initial proposal through architectural refinement, ...
# Technical Analysis: uuidv7() Interval Shift Boundary Validation ## Core Problem The `uuidv7(interval)` function in PostgreSQL accepts arbitrary interval offsets to shift the timestamp embedded in ...
# Technical Analysis: Segmentation Fault from Reentrancy in RI_FKey_cascade_del ## Core Problem This thread identifies a **use-after-free vulnerability** in PostgreSQL's referential integrity (RI) ...
# Monthly Summary: Cirrus CI Shutdown and PostgreSQL CI Infrastructure Migration (May 2026) ## Overview With Cirrus CI's June 1, 2026 shutdown deadline looming, the PostgreSQL community moved from d...
# Monthly Summary: Schema-Qualified Names in Publication Error Messages (May 2026) ## Overview This thread reached completion in May 2026, progressing from API design refinement through final commit...
# Monthly Summary: Prevent Repeated Deadlock-Check Signals in Standby Buffer Pin Waits (May 2026) ## Overview This thread addresses unnecessary repeated signaling in PostgreSQL's hot standby recover...
# Technical Analysis: `log_postmaster_stats` — Periodic Postmaster Activity Reporting ## Core Problem The PostgreSQL postmaster process — the central coordinator responsible for forking new backend ...
# Monthly Summary: Avoid Orphaned Object Dependencies, Take 3 — May 2026 ## Overview This month saw significant progress toward landing the patch that prevents orphaned object dependencies in Postgr...
# Analysis: Code Contributions Metrics for PostgreSQL — Methodology, Automation, and Identity Resolution ## Core Problem This thread spans two years (2024-2025) of Robert Haas's annual effort to qu...
# Parallel INSERT SELECT take 2 — May 2026 Monthly Summary ## Overview After five years of dormancy, this thread was revived by Tomas Vondra with a fundamental reassessment of the approach taken by ...
# CREATE INDEX CONCURRENTLY on Partitioned Tables: Deep Technical Analysis ## The Core Problem PostgreSQL's `CREATE INDEX CONCURRENTLY` (CIC) has never supported partitioned tables. When a user issu...
# Dump Statistic Issue with Index on Expressions — May 2026 Summary ## Overview A reported bug in `pg_dump --statistics-only` (new in PostgreSQL 18) involving cross-index attribute name leakage was ...
# Deep Technical Analysis: Generic Plans and "Initial" Pruning ## The Core Problem When PostgreSQL executes prepared statements against partitioned tables using **generic plans**, performance degra...
# Monthly Summary: `pg_get_trigger_ddl()` and `pg_get_policy_ddl()` — May 2026 ## Overview This thread encompasses two intertwined sub-patches under Andrew Dunstan's **Retail DDL Functions** project...
# Monthly Summary: Add NESTED_STATEMENTS Option to EXPLAIN (May 2026) ## Overview This thread saw rapid iteration from v1 through v4 of a patch adding `NESTED_STATEMENTS` as a new EXPLAIN option, tr...
# Monthly Summary: contrib/anyarray — Generalizing intarray to Any Array Type (May 2026) ## Overview A new contrib module `anyarray` was proposed to generalize `contrib/intarray`'s set-style operati...
# Monthly Summary: Fix Overflow and Underflow in regr_r2() (and regr_intercept()) ## Overview This thread addresses numerical instability in PostgreSQL's `regr_r2()` and `regr_intercept()` aggregate...
# Deep Technical Analysis: Optimizing Nested Loop Left Joins by Short-Circuiting Inner Scans ## The Core Problem When PostgreSQL executes a Nested Loop Left Join where the join condition (ON clause...
# Alert Clients When Prepared Statements Are Deallocated ## Core Problem When a PostgreSQL client creates prepared statements (at the protocol level), those statements can be invalidated by SQL comm...
# Adding a Stored Generated Column Without Long-Lived Locks — May 2026 Summary ## Overview This thread proposes a two-patch approach to allow adding stored generated columns to existing PostgreSQL t...
# Add XMLNamespaces to XMLElement - Technical Analysis ## Core Problem PostgreSQL's `xmlelement()` function, which constructs XML elements per the SQL/XML standard, lacks support for the `XMLNAMESP...
# Non-superuser Subscription Owners: Deep Technical Analysis ## Core Problem PostgreSQL's logical replication system was designed with the assumption that subscriptions would always be owned and ope...
# Add Wait Events for Server Logging Destination Writes ## Core Problem PostgreSQL's observability infrastructure has a blind spot in the logging subsystem. When a backend calls `write(2)` to emit ...
# Fix Regression in vacuumdb --analyze-in-stages for Partitioned Tables ## Core Problem A refactoring commit (`c4067383cb2`) introduced a subtle regression in `vacuumdb`'s handling of partitioned t...
# PostgreSQL 19 Beta 1 Release Announcement Draft Review ## Overview This thread concerns the community review of the PostgreSQL 19 Beta 1 release announcement draft, a standard part of the PostgreS...
# Set Notice Receiver Before libpq Connection Startup — May 2026 Summary ## Problem PostgreSQL's `libpqsrv` infrastructure (used by dblink, postgres_fdw, and other extensions for outbound libpq conn...
# Performance Degradation in libpq/pgbench Due to OpenSSL 3.x Global Lock Contention ## Core Problem When using `pgbench --connect` (which tests new connection establishment rate) against pgbouncer...
# Technical Analysis: RISC-V Zbb Popcount Optimization and Clang Auto-Vectorization Bug ## Core Problem This thread encompasses two distinct but related problems for PostgreSQL on RISC-V: 1. **Perf...
# Technical Analysis: Message Wording/Formatting Cleanup Patches ## Core Problem This thread addresses a collection of internationalization (i18n), style consistency, and naming issues discovered du...
# Monthly Summary: Fix Mismatched Deallocation Functions (May 2026) ## Overview Tristan Partin proposed a mechanical refactor to fix allocator/deallocator mismatches in PostgreSQL's frontend code, u...
# Eager Aggregation in PostgreSQL: Deep Technical Analysis ## Core Problem Eager aggregation is a query optimization technique that partially pushes a GROUP BY aggregation past a join operation, per...
## Incremental Update: Committer Acknowledgment No substantive technical progress since the prior analysis. Amit Kapila (committer) responded with a brief acknowledgment: - Confirms the fix "LGTM" (...
## Incremental Update: Robert Haas Pushes Back on Need for New libpq Entrypoint Robert Haas returns after pgconf.dev and directly challenges the fundamental premise of the patch — that a new libpq fu...
# Injection Points: Switching Wait/Wakeup from Latches to Atomics ## Core Problem The injection_points testing infrastructure in PostgreSQL provides a mechanism for test code to synchronize backend...
# COPY ON_CONFLICT TABLE — May 2026 Monthly Summary ## Overview This thread proposes extending PostgreSQL's `COPY FROM` with the ability to redirect rows that violate unique/primary key constraints ...
# Monthly Summary: Fix UPDATE/DELETE FOR PORTION OF with Inheritance Tables (May 2026) ## Overview This thread addresses a correctness bug in PostgreSQL's temporal DML (`FOR PORTION OF`) when applie...
# Monthly Summary: Preserve Replication Origin OIDs in pg_upgrade (May 2026) ## Problem Statement When `pg_commit_ts` SLRU data is migrated byte-for-byte during pg_upgrade, the embedded 2-byte `RepO...
# ECPG: Inconsistent Behavior with GET/SET DESCRIPTOR Multiple Header Items ## Core Problem The ECPG (Embedded SQL in C for PostgreSQL) precompiler has a bug where its **parser accepts syntax that ...
# Index Prefetching for PostgreSQL: Deep Technical Analysis ## The Core Problem PostgreSQL's index scan execution model has a fundamental I/O inefficiency: when performing a regular index scan (btr...
# Technical Analysis: Fix Doubled-Word Typos and Punctuation in Code Comments ## Problem Statement This is a straightforward code quality patch that addresses three instances of doubled-word typos ...
# Beautify Read Stream "Per Buffer Data" APIs ## Core Problem PostgreSQL's read stream infrastructure (introduced to support prefetching and efficient sequential/random I/O patterns) exposes a "per...
# Deep Technical Analysis: Fast-Path Planning for OLTP Star Joins ## The Core Problem PostgreSQL's join order optimization uses dynamic programming (DP) to explore all possible join orderings, buil...
# Uninitialized Memory Access in zic ## Core Problem PostgreSQL's `zic` (timezone compiler) utility, which is used during the build process to compile timezone data files into binary format, contai...
# Bloom Filter Pushdown for Hash Joins: Deep Technical Analysis ## Core Problem Hash joins in PostgreSQL process outer tuples by probing the hash table for each one. When a join is highly selective...
# Technical Analysis: OAuth `shutdown_cb` Documentation Bug ## Core Problem The OAuth validator module API in PostgreSQL 18 includes a `shutdown_cb` callback that implementations can register. Howe...
# Technical Analysis: Fix Recomputation of Required LSN on restart_lsn-only Advancement ## Core Problem The issue resides in `LogicalConfirmReceivedLocation()`, a function in PostgreSQL's logical r...
## Technical Analysis: dependencyLockAndCheckObject() Terminology Fix ### The Core Problem PostgreSQL's dependency tracking system distinguishes between two roles in a dependency relationship: - **...
# Monthly Summary: Startup Process Deadlock — WaitForProcSignalBarriers vs Aux Process (May 2026) ## Overview This thread resolved a long-latent race condition in PostgreSQL's ProcSignalBarrier (PSB...
# Technical Analysis: Secondary Hash to Split Stuck Hash-Join Batches ## The Core Problem: Hash Join Batch Splitting Degeneracy PostgreSQL's hash join executor partitions the inner relation into bat...
# Technical Analysis: Improving REPACK (CONCURRENTLY) Error Messages ## Core Problem The `REPACK (CONCURRENTLY)` feature — a relatively new addition to PostgreSQL that allows online table repacking...
# Make transformAExprIn() Return a Flattened Bool Expression Directly ## Core Problem In PostgreSQL's query transformation pipeline, the function `transformAExprIn()` (located in `src/backend/parse...
# Technical Analysis: Update our timezone code to IANA tzcode2026b ## Core Problem PostgreSQL maintains a vendored copy of the IANA timezone library (tzcode) within its source tree, used to handle t...
## Incremental Update: No Substantive Technical Progress The single new message from Hayato Kuroda is a brief clarification/follow-up to a prior exchange with Sergey. Kuroda reiterates his concern ab...
# Monthly Summary: Conflict Log History Table for Logical Replication — May 2026 ## Overview May 2026 saw this proposal mature from a design-settled but implementation-rough state into extensive lat...