The History of the Decline and Fall of In-Memory Database Systems

December 3, 2024

A decade ago, there was a sudden surge of high-performance in-memory systems dominating the world of interactive analytics. Today, almost everyone has gone back to using persistent storage. Does this mean that building these in-memory systems was a mistake?

Offset Considered Harmful or: The Surprising Complexity of Pagination in SQL

November 19, 2024

Have you ever wondered why you sometimes see duplicate results when clicking on the second page of a website? In this blog post, we explore techniques for result pagination, how they impact the work necessary to compute the results, and why using the SQL offset keyword for it is not a good idea.

How to Correctly Sum Up Numbers

October 30, 2024

When you learn programming, one of the first things every book and course teaches is how to add two numbers. So, developers working with large data probably don't have to think too much about adding numbers, right? Turns out it's not quite so simple!

Why You Shouldn't Forget to Optimize the Data Layout

October 8, 2024

The underlying data layout of your program can either help or hurt your algorithms. We explore how to improve the runtime of your program by analyzing the impact of the data layout on low-level properties such as cache line optimizations and SIMD execution, as well as other memory-level optimizations such as compression.

The Hidden Cost of Data Movement

September 24, 2024

Moving data between disk, memory, caches, and CPU registers is one of the most critical paths when processing large amounts of data. In this post, we explore the often-overlooked costs of these data movements and show how they can be reduced for algorithms in general and specifically in a database system.

Why I Prefer Exceptions to Error Values

September 10, 2024

Exceptions are often a better way to handle errors than returning them as values. We argue that traditional exceptions provide better user and developer experience, and show that they even result in faster execution.

Reclaiming SQL’s Declarative Power

August 27, 2024

A good SQL optimizer can dramatically improve query performance, allowing you to focus on writing readable SQL instead of getting lost in the details of database optimization. This post discusses query optimizers, and query unnesting in particular, to emphasize the importance of query optimization.

Can You Do Both: Fast Scans and Fast Writes in a Single System?

August 13, 2024

Most database systems focus on either analytical or transactional performance due to their contrasting data access patterns. CedarDB, however, achieves high performance in both areas (HTAP) with its unified storage system, Colibri, which combines compressed columnar data and row-based storage.

A Deep Dive into German Strings

July 30, 2024

Our last post on our "German Strings" has received tremendous attention. We want to follow up on some of your comments and dive deeper into the reasons behind some of our string optimizations.

Why German Strings are Everywhere

July 16, 2024

Many data processing systems have adapted our custom string format. Find out what makes it so special and why it is so relevant to them.