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DBMS Weekly — 2026-06-14 (week of 2026-06-08–2026-06-14)

PostgreSQL

  • How the Other Half Counts — Christophe Pettus surveys how Oracle, Db2, MySQL, SQLite, DuckDB, and Snowflake gather planner statistics vs. PostgreSQL's sampling ANALYZE; the real axis turns out to be stats freshness and who owns it, not the join algorithm. (thebuild.com)
  • All Your GUCs in a Row: deadlock_timeout — clarifies that deadlock_timeout sets how often PostgreSQL checks for a deadlock, not how long a deadlock is tolerated; part of a near-daily GUC-internals series. (Christophe Pettus · thebuild.com)
  • All Your GUCs in a Row: DateStyle — on why DateStyle conflates two unrelated behaviours (input parsing and output formatting) in a single GUC. (Christophe Pettus · thebuild.com)
  • All Your GUCs in a Row: data_sync_retry — the GUC born from the Postgres fsync-reliability durability saga, and why the default is what it is. (Christophe Pettus · thebuild.com)
  • My Three Top PostgreSQL 19 Features — Stefanie Janine walks through INSERT ... ON CONFLICT DO SELECT, the new in-core REPACK (with CONCURRENTLY), and SQL/PGQ graph queries landing in PG19. (proopensource.it)
  • PostgreSQL Anonymizer 3.1: local differential privacy — Dalibo's data-masking extension adds local-differential-privacy masking techniques (announcement light on detail; verify changelog before relying on it). (Dalibo · postgresql.org)

PostgreSQL mailing lists

  • [hackers] FK fast-path: OOB write + missed FK checks during batched RI checks — three defects in PG19's new batched foreign-key fast path (an out-of-bounds write and two paths silently committing FK-violating orphan rows); reproducers confirmed, the fix is pushed and on the PG19 Open Items list. Data-integrity regression in a just-shipped beta feature. (Amit Langote · pgsql-hackers) [committed]
  • [hackers] Commit Sequence Numbers and Visibility (CSN snapshots) — Jeff Davis proposes concrete rules for CSN-based snapshot acquisition; Matthias van de Meent pushes back that coupling snapshot acquisition to durability would impose synchronous-flush waits on readers, counter-proposing separate durability-horizon WAL records. Core architectural debate for a future MVCC redesign. (Jeff Davis · pgsql-hackers) [open]
  • [hackers] RFC: a constraint-enforcement layer for cross-partition uniqueness — Greg Burd reframes the perennial "global unique index on partitioned tables" problem as a separate pg_constraint_method abstraction (a lightweight WAL-logged membership map) instead of a full global index, citing prior global-index attempts. (Greg Burd · pgsql-hackers) [open]
  • [hackers] Any JIT-compiled query crashes (SIGILL) on libLLVM 19 + ASAN CI build — cfbot failures blamed on the Row Pattern Recognition patch turn out to be a feature-independent crash: on the ASAN+LLVM 19.1 config any JIT-compiled query SIGILLs on plain master; minimal repro and regression test posted. Was masking real CI signal on in-flight patches. (pgsql-hackers) [patch posted]

Community pulse

Wider DBMS & distributed data

  • The only scalable delete in Postgres is DROP TABLE — argues that under MVCC, bulk DELETE doesn't cheaply reclaim space (dead tuples, VACUUM, bloat), so partition-drop / DROP TABLE is the only delete that scales; lively HN discussion. (planetscale.com)
  • Our MongoDB TLA+ workshop — Murat Demirbas reports an order-of-magnitude better onboarding when LLM assistance removes TLA+ syntax as the barrier, letting engineers formally model real replication/storage subsystems hands-on; includes a distilled "AI-assisted TLA+ best practices" guide. (muratbuffalo.blogspot.com)
  • Postgres by Example — example-driven Postgres reference repo that surfaced on HN; useful as a teaching/cheat-sheet resource. (github.com)

Commercial engines (SQL Server, Oracle, MySQL, …)

International (non-English sources)

  • Postgres Pro evolves a "Virtual DBA" LLM agent's environment with record/replay — Postgres Professional ran an evolutionary search over a Postgres-diagnosis agent's setup (prompts, analysis steps, MCP tools) by recording and fast-replaying real workloads; a headline finding is that handing the agent more tools can actually worsen its final verdict. (Postgres Professional · habr.com) [ru] (orig: «Промпты, RAG, LLM-тюнинг, Harness… Идём дальше?»)
  • Three discovery problems with Postgres master/replica — and a lightweight fix — finding the master after failover, picking a replica within an acceptable lag, and guaranteeing read-your-writes, solved with a small HTTP service (pg-status) instead of DNS/HAProxy hacks that don't understand replication LSN. (krylosov-aa · habr.com) [ru] (orig: «Три задачи discovery при работе с PostgreSQL master/replica — и как их решить»)
  • OceanBase lands a batch of papers at SIGMOD/VLDB 2026 — surfaced via the Chinese DB community 墨天轮; the Ant Group distributed-RDBMS vendor's top-venue haul, with three worth mining for our own engine: TaCo (query-aware subspace collision for high-dimensional ANN search), ESTune (Bayesian uncertainty-guided early stopping for knob tuning), and Secure Multi-Party Sampling over Joins (VLDB). (墨天轮 / modb.pro) [zh] (orig: «OceanBase 多篇论文被国际顶会录用»)

Research & cutting edge

23 items · sources scanned: ~30 · community threads scanned: HN (40 DB stories) · international: 3 (ru, zh) · filtered out as marketing/ads: 8