<p><strong>TLDR:</strong> Amazon Redshift’s new RG instances replace RA3 with Graviton processors, a built-in data lake query engine, and no more Spectrum per-TB charges. PostgreSQL 19 is shaping up to be a significant release, adding plan hints, temporal range updates, and atomic get-or-create inserts. DuckDB released Quack, a client-server protocol that finally addresses the single-writer limitation. MySQL 9.7.0 went GA with replication and query optimization improvements across the 9.x cycle.</p>
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<h2>Amazon Redshift RG instances replace RA3 with Graviton and built-in Iceberg support</h2>
<p>Redshift’s new RG instances run warehouse workloads up to 2.2x faster than RA3 at 30% lower price per vCPU, and the integrated data lake query engine delivers up to 2.4x faster Iceberg performance. The bigger operational win: Redshift Spectrum is gone, along with its $5/TB scanning fee and separate scanning fleet. Data lake queries now stay inside the VPC. Migration from RA3 is supported via Elastic Resize (10-15 min downtime) or Snapshot and Restore with no changes to external tables or application code. RG instances are generally available across 26 AWS regions.</p>
<h2>PostgreSQL 19 adds pg_plan_advice, temporal range edits, and ON CONFLICT DO SELECT</h2>
<p>Three separate PostgreSQL 19 features landed in coverage today. <code>pg_plan_advice</code> brings external query plan hints via GUC settings and an <code>EXPLAIN (PLAN_ADVICE)</code> workflow — no hint embedding in SQL text, and a feedback system that tells you whether each hint actually matched. <code>UPDATE/DELETE FOR PORTION OF</code> handles temporal range modifications by automatically splitting rows, completing the SQL:2011 temporal feature set started in PostgreSQL 18. <code>ON CONFLICT DO SELECT</code> enables atomic get-or-create: on a unique constraint conflict, the existing row is returned via <code>RETURNING</code> with no dead tuples and no CTE workarounds — benchmarks show it’s nearly 4x faster than the common <code>DO UPDATE</code> no-op pattern.</p>
<h2>DuckDB releases Quack, a client-server protocol for multi-process writes</h2>
<p>Quack is a new DuckDB extension that exposes a client-server protocol over HTTP, using DuckDB’s own serialization format. The main thing it solves is concurrent writes from multiple processes, which DuckDB’s in-process architecture has never supported. Benchmarks show it outperforms PostgreSQL and Arrow Flight SQL for bulk transfers — 60 million rows in under 5 seconds — and beats PostgreSQL for small concurrent writes up to 8 threads. Security defaults to random tokens and localhost-only binding. A production release is planned alongside DuckDB v2.0 in fall 2026.</p>
<h2>Netflix hits 84% cache hit rate in Apache Druid with interval-aware caching</h2>
<p>Netflix’s engineering team published how they achieved an 84% query result cache hit rate in Apache Druid by making the cache aware of time intervals in queries. The approach significantly reduces query load at Netflix’s scale without architectural changes to the query layer itself. Worth reading if you’re running Druid for real-time analytics and haven’t looked hard at cache effectiveness.</p>
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<h2>Also notable</h2>
<ul>
<li><strong>MySQL 9.7.0 GA:</strong> Consolidates the 9.x cycle with improved replication observability, telemetry, and query optimization; several features previously enterprise-only are now in the Community Edition.</li>
<li><strong>Figma CDC migration:</strong> Rebuilt their RDS PostgreSQL-to-Snowflake pipeline around Change Data Capture and Kafka, dropping data freshness from 30+ hours to under 3 hours while eliminating dedicated export replicas that cost millions annually.</li>
<li><strong>Meta data ingestion migration:</strong> Migrated tens of thousands of petabyte-scale MySQL scrape jobs to a self-managed service using shadow testing, reverse shadow rollout, and CDC-aware rollback to stop bad data propagation.</li>
<li><strong>Vector search in Tinybird/ClickHouse:</strong> A team cut vector search latency from 48 seconds to 80-200ms on 19.35 million embeddings by consolidating 58 fragmented HNSW graphs into one and increasing the similarity index cache from 5 GB to 40 GB so the full 35 GB index stays in RAM.</li>
<li><strong>Redis dynamic endpoints (public preview):</strong> Redis Cloud now supports stable hostnames that redirect between databases without app config changes, decoupling migration coordination from endpoint updates.</li>
<li><strong>Redis retrospective:</strong> A sharp post argues Redis lost its identity by expanding into document storage, search, streaming, time-series, and vector — none done as well as dedicated tools — and that Valkey’s rise is the market saying it just wants the fast cache from 2011.</li>
<li><strong>DuckDB Monthly #41:</strong> DuckDB 1.5.0 ‘Variegata’ released with a VARIANT type and CLI improvements; DuckLake v1.0 addresses small-change inefficiencies in lakehouse architectures; a new <code>duck_lineage</code> extension adds automatic column-level lineage via OpenLineage.</li>
<li><strong>Time-series storage design:</strong> Practical breakdown covering normalization vs. flat schemas in PostgreSQL (42% storage reduction), columnar Parquet compression (up to 434x), two-dimensional partitioning to avoid write hotspots, and downsampling resolution ladders.</li>
<li><strong>ClickHouse vs MySQL on OLAP:</strong> Benchmark over 50 million rows shows ClickHouse completing a 3-way GROUP BY in 0.3 seconds vs MySQL’s 3 minutes 28 seconds, with 54% storage savings from columnar compression.</li>
<li><strong>Appwrite BigInt columns:</strong> Appwrite Databases now supports 64-bit signed integer columns natively, with atomic increment/decrement operators for concurrent counter updates without client-side coordination.</li>
<li><strong>AI agent backup risk:</strong> With agents holding write permissions, traditional backups stored in the same account are inside the blast radius; the argument is for immutable WORM backups built outside the agent’s permission scope.</li>
<li><strong>Cursor pagination in EF Core:</strong> Practical walkthrough showing cursor-based pagination using a Base64-encoded cursor in a WHERE clause with a composite index, enabling an index seek instead of a full scan that degrades at scale.</li>
</ul>


Query optimization, schema design, and data store coverage across PostgreSQL, MongoDB, Redis, and more.

Databases Digest

A roundup of major database news: Amazon Redshift's new RG instances replace RA3 with Graviton processors, delivering up to 2.2x faster performance at 30% lower cost and eliminating Redshift Spectrum's per-TB fees. PostgreSQL 19 is adding three notable features: pg_plan_advice for external query plan hints, UPDATE/DELETE FOR PORTION OF for temporal range edits, and ON CONFLICT DO SELECT for atomic get-or-create operations (nearly 4x faster than the DO UPDATE workaround). DuckDB released Quack, a client-server extension enabling concurrent multi-process writes over HTTP. MySQL 9.7.0 went GA with replication and query optimization improvements. Additional coverage includes Netflix's 84% Druid cache hit rate, Figma's CDC pipeline migration cutting data freshness from 30+ hours to under 3 hours, ClickHouse vs MySQL OLAP benchmarks, and vector search latency improvements from 48 seconds to 80-200ms.

Redshift gets Graviton-powered RG instances, PostgreSQL 19 adds three query features