DBMS Weekly — 2026-06-15 (week of 2026-06-15–2026-06-21)

PostgreSQL

• POSETTE: An Event for Postgres 2026 is a wrap — all 44 talks on YouTube — the free virtual event (Jun 16–18, organised by the Postgres team at Microsoft) ran four livestreams; every talk is now un-gated on YouTube. The internals-relevant picks for a hacker:
  • Postgres 19 Hackers Panel: What's In, What's Out, & What's Next — Álvaro Herrera, Heikki Linnakangas, Melanie Plageman, and Thomas Munro on what made the PG19 feature freeze and what stalled. (keynote)
  • random_page_cost — why the default is 4.0 and should you lower it? — Tomas Vondra dissects the planner's random-vs-sequential I/O cost ratio and when the SSD-era default misleads.
  • Fuzzing PostgreSQL — Adam Wolk applies fuzzing to libpq, the client library that parses every server message; a template for finding edge-case bugs in stateful C code.
  • The Wonderful World of WAL — Bruce Momjian walks the write-ahead log as the substrate for crash recovery, PITR, and physical/logical replication.
  • pg_stats: How Postgres Internal Stats Work — Richard Yen on the statistics model behind seq-scan-vs-index-scan planner decisions.
  • Journey of developing a performance optimization feature in PostgreSQL — Rahila Syed on systematically diagnosing and fixing an internals bottleneck end-to-end.
  • Past, Present, and Future: Logical Decoding and Replication — Hari Kiran traces the arc from the low-level decoding API to today's logical replication.
  • Exploring property graphs with SQL/PGQ in PostgreSQL — Ashutosh Bapat on the in-core graph-query syntax landing in PG19.
• pg_kpart 1.0 — new extension that rejects any query against a protected partitioned table that can't prune a single partition, turning "always filter on the partition key" from convention into a database-enforced guarantee. (Gilles Darold · HexaCluster)
  • throws a clear error (with a dedicated SQLSTATE) instead of letting a key-less query trigger a server-wide full-hierarchy scan
  • audit mode for staged rollout; blacklist/whitelist scoping to target specific tables
• powa-archivist 5.1.2 — the core collector of the PostgreSQL Workload Analyzer project ships a maintenance release. (PoWA team · Marc Cousin)
  • new: per-module retention (set different history-retention windows per collected extension)
  • compatible with all supported PostgreSQL versions

PostgreSQL mailing lists

• [hackers] Conflict log history table for Logical Replication — a lost-conflict bug surfaces — the PG20-targeted feature that lets a subscription log apply-time conflicts to a system-managed table (in a pg_conflict schema) instead of just the server log saw heavy review this week. vignesh C reported a real defect: a concurrent ALTER SUBSCRIPTION that switches the conflict-log destination drops the log table while the apply worker still holds its cached OID, so table_open() fails, the worker exits (code 1), and the conflict record is logged nowhere; reviewers also flagged that arbitrary objects (extensions, collations, operators) can be created in pg_conflict and that DROP of the log table errors inconsistently with INSERT/UPDATE. (vignesh C, Peter Smith, Shlok Kyal, Amit Kapila · pgsql-hackers) [patch posted]

CommitFest (open: PG20-1, #59)

• Balance (Jun 15–21): PG20-1 is in its collection phase (in-progress Jul 1–31) and saw net inflow — several new patch records, a few committed/withdrawn. This is the first week the digest tracks the CommitFest, so the week-over-week delta baseline starts now; absolute totals will be diffed from next run. (source: per-CF activity log)
• New this week: Global temporary tables (deanr) — a fresh patch record for the long-requested GTT feature: tables whose definition is shared cluster-wide but whose rows and statistics stay private to each session (the SQL-standard / Oracle-style global temp table Postgres still lacks). Also new: PROXY protocol support (#6916 — lets the backend see the real client address behind a load balancer) and pg_dump: skip pg_init_privs entries for non-existent roles (#6915, Hüseyin Demir).
• Closed in-window: Fix PL/Python crash when a SRF is redefined mid-execution (#6917, filed and committed same day by Tom Lane) and Fix publisher-side sequence permission reporting (#6911, committed); pg_restore --no-globals output for pg_dumpall archives (#6899) withdrawn.

Wider DBMS & distributed data

• Why we built Azure HorizonDB for PostgreSQL — Dingding Lu (POSETTE) on Microsoft's new cloud-native, Postgres-compatible engine that decouples storage to keep latency predictable under spiky traffic and scale reads without external bolt-ons; a useful look at how a major vendor is re-architecting Postgres for the cloud. (Microsoft · posetteconf.com)
• pg_lake: Postgres as a lakehouse — Marco Slot (POSETTE) on the extension approach to making Postgres a competent analytics/lakehouse front-end (Iceberg/object-storage interaction) rather than bolting on a separate warehouse. (posetteconf.com)

Migration experience

• Migrating VLDBs from Oracle to Azure Database for PostgreSQL — Adithya Kumaranchath (POSETTE) shares field-tested strategies for moving multi-terabyte Oracle databases onto a managed Postgres service, where the cloud target adds real constraints over a self-managed migration. (posetteconf.com)

International (non-English sources)

• PostgreSQL 19 ushers in a new era of temporal-table design (Part 1) — converts pgbench's standard schema to a temporal design using tsrange valid_at columns, PRIMARY KEY … WITHOUT OVERLAPS, btree_gist, and PG19's UPDATE … FOR PORTION OF; EXPLAIN ANALYZE shows point-in-time lookups stay cheap (Index Scan / Bitmap Index Scan on a single GiST index). Argues Postgres is now uniquely suited to temporal tables — the only major engine combining a range-overlap index with WITHOUT OVERLAPS primary keys — versus SQL Server's split current/history-table approach. (harukat · SRA OSS · qiita.com) [ja] (orig: 「PostgreSQL19でテンポラルテーブル設計の新時代へ(1)」)

New sources added this week

• pghackers.com — PostgreSQL Hackers Explorer — AI-assisted search/exploration over the pgsql-hackers archive; potentially a faster way to triage in-window threads than the raw monthly index. (surfaced via search; evaluate over coming weeks)

11 items · sources scanned: ~31 (Planet PostgreSQL, PostgreSQL news archive, pgsql-hackers via mail-archive.com, CommitFest PG20-1 activity log, pganalyze, thebuild.com, POSETTE, Qiita [ja], Habr [ru], modb.pro [zh], arXiv cs.DB) · international: 1 (ja) · filtered out as marketing/ads: ~6 (incl. recycled Crunchy↔Snowflake from 2025, vendor product talks). Community pulse, Research, and a ru/zh International item omitted: nothing could be confirmed inside the Jun 15–21 window without fabricating links or engagement counts.