08 August 2026
57 new posts across 9 database and data engineering sources — 18 worth your time.
On Benchmarking
This post explores the methodology of database and system benchmarking, arguing that a raw performance number is meaningless without understanding why a system stops scaling and whether the test matches production workloads. It warns against choosing architectures based solely on isolated high-throughput metrics.
Data Engineering Weekly · 08 August 2026 · Read the original →
Avi Vallarapu: Tuning PostgreSQL HOT Updates - A HammerDB Benchmark
This post details how to leverage Heap-Only Tuple (HOT) updates in PostgreSQL to bypass the overhead of standard vacuuming. Using a HammerDB TPROC-C benchmark, it demonstrates how tuning the table fillfactor parameter reduces bloat growth and eliminates vacuum bottlenecks.
Planet PostgreSQL · 08 August 2026 · Read the original →
How Mercado Libre rebuilt its observability platform on ClickHouse Cloud with 50x faster trace queries
This case study details how Mercado Libre migrated its observability platform to ClickHouse Cloud to handle an ingestion rate of 400 million spans per minute. The migration achieved up to 89% data compression and reduced trace query latencies from over five minutes to just four seconds.
ClickHouse · 08 August 2026 · Read the original →
Umair Shahid: PostgreSQL Lockup vs Stale Connection: How to Tell Them Apart
This post provides a guide to diagnosing database connection failures, specifically distinguishing between a genuine PostgreSQL server lockup and a stale connection that silently died in the application's connection pool. It highlights how identical-looking application errors can stem from entirely different network or pool failures.
Planet PostgreSQL · 08 August 2026 · Read the original →
Alexey Evlampiev: Your Transaction Boundary Belongs in the Program, Not the Filename
This article examines how to structure phased schema migrations in PostgreSQL, which often require a mix of transactional and non-transactional operations. It argues that migration frameworks should embed transaction boundaries directly within the SQL program itself rather than relying on external file-naming metadata.
Planet PostgreSQL · 08 August 2026 · Read the original →
Massively parallel Postgres backups
This post discusses the architectural challenges of executing consistent, encrypted database backups every 12 hours on highly active production databases. It focuses on achieving zero impact on production queries while handling massive data volumes through parallel processing.
PlanetScale · 08 August 2026 · Read the original →
Multi-agent observability: why one trace isn't enough
This post addresses the unique challenges of monitoring multi-agent AI systems, where interactions span multiple execution loops, shared memory states, and external tool calls. It explains why traditional single-trace observability patterns fail to capture the asynchronous, distributed nature of multi-agent workflows.
Redis · 08 August 2026 · Read the original →
Postgres Managed by ClickHouse Benchmarks
In PostgresBench at 500 GB, Postgres managed by ClickHouse achieved 26,328 transactions per second on a 16 vCPU, 64 GB RAM instance. This result was 2.4 to 5.2 times the throughput of Crunchy Bridge, Aurora, Neon, and RDS using the same benchmark parameters for transactional workloads.
clickhouse.com · 08 August 2026 · Read the original →
Cloud Data Warehouse Cost and Latency
Organizations are encountering cost and latency issues with serverless data warehouses like BigQuery, particularly due to 'bytes-scanned' pricing for frequently executed queries. Solutions like ClickHouse offer compute-based pricing and achieve sub-second latency for high-concurrency, real-time analytical workloads, contrasting with the batch-oriented nature of some traditional warehouses.
clickhouse.com · 08 August 2026 · Read the original →
Concurrency vs. Throughput: why more parallelism can make databases slower
Examines a 16-minute MySQL production outage caused by a sudden traffic spike that spiraled into lock contention. The post tracks how query throughput collapsed from 15,000 queries per second down to 1,500 as concurrency and error rates peaked.
PlanetScale · 08 August 2026 · Read the original →
Asynchronous I/O in DuckDB: Work, Thread, Work
Explains how DuckDB historically relied on early filter and projection pushdowns to avoid I/O bottlenecks on local disks. It details the architectural shift toward asynchronous I/O needed when querying remote or high-latency storage where pruning alone is insufficient.
DuckDB · 08 August 2026 · Read the original →
Alexey Evlampiev: Your ALTER TABLE Is Fast. The Queue Behind It Is Not.
Demonstrates how an ALTER TABLE statement that executes in just six milliseconds can stall all incoming read queries on a table for sixteen seconds. It illustrates how PostgreSQL lock queues cause cascading query delays regardless of actual execution speed.
Planet PostgreSQL · 08 August 2026 · Read the original →
Fixed cadence to seconds: making ClickHouse Cloud autoscaling more reactive
Details the re-architecture of ClickHouse Cloud's autoscaling orchestration using Kubernetes controller-runtime and a ClickHouse-backed signals table. The new mechanism introduces a reactive fast path that triggers scale-up events in seconds instead of relying on periodic polling.
ClickHouse · 08 August 2026 · Read the original →
Radim Marek: The DISTINCT in your COUNT
Analyzes how using DISTINCT inside a COUNT aggregate forces PostgreSQL to run queries on a single core. It explains why this single keyword silently disables parallel query execution across worker processes for large scans.
Planet PostgreSQL · 08 August 2026 · Read the original →
Elizabeth Garrett Christensen: Postgres COUNT(DISTINCT) Too Slow? Fast Approximation Guide
Compares exact COUNT(DISTINCT) queries against HyperLogLog probabilistic estimation in PostgreSQL, showing execution times dropping from 671ms to 320ms. It demonstrates how hashing and aggregating into HLL sketches enables instant mergeable cardinality queries.
Planet PostgreSQL · 08 August 2026 · Read the original →
Advanced Data Modeling in Amazon Keyspaces
Amazon Keyspaces now supports User-Defined Types (UDTs) and Protocol Buffers (Protobuf) for modeling complex data. This allows grouping related attributes to improve data model clarity and application performance in a serverless database.
aws.amazon.com · 08 August 2026 · Read the original →
Managed Postgres OLAP Performance Comparison
A comparison of managed Postgres services for OLAP workloads highlights how different storage engines, I/O paths, and cache behaviors impact performance. ClickHouse Managed Postgres demonstrated superior throughput compared to Aurora, despite Aurora having twice the RAM in the tested configuration.
clickhouse.com · 08 August 2026 · Read the original →
Databricks Lakeflow for Data Engineering
Databricks introduced Lakeflow, an end-to-end solution for data engineering, encompassing ingestion, transformation, and orchestration of data. It supports both batch and streaming pipelines built on Apache Spark Declarative Pipelines.
Databricks · 08 August 2026 · Read the original →
Another week of trying to benchmark our way out of bad queries.
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