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Databases & Data

The most popular blog posts about databases & data on Hacker News. 332 posts.

2017
45

Interesting data structures: the BK-tree

A BK-tree is a tree data structure specialized to index data in a metric space . A metric space is essentially a set of objects which we equip with a distance function $d(a, b)$ for every pair of elements $(a, b)$. This distance function must satisfy a set of axioms in order to ensure it’s well-behaved. The exact…

46

Working with time in Postgres

A massive amount of reporting queries, whether really intensive data analysis, or just basic insights into your business involving looking at data over a certain time period. Postgres has really rich support for dealing with time out of the box, something that’s often very underweighted when dealing with a database…

47

Unlearning descriptive statistics

If you've ever used an arithmetic mean, a Pearson correlation or a standard deviation to describe a dataset, I'm writing this for you. Better numbers exist to summarize location, association and spread: numbers that are easier to interpret and that don't act up with wonky data and outliers.

49

Modes, Medians and Means: A Unifying Perspective

Introduction / Warning Link to heading Any traditional introductory statistics course will teach students the definitions of modes, medians and means. But, because introductory courses can’t assume that students have much mathematical maturity, the close relationship between these three summary statistics can’t be…

55

Better Database Migrations in Postgres

As your database grows and scales there are some operations that you need to take more care of than you did when you were just starting. When working with your application in your dev environment you may not be fully aware of the cost of some operations until you run them against production. And at some point most of…

58

CockroachDB beta-20161013

CockroachDB is a distributed SQL database, loosely patterned after Google Spanner and designed for semi-synchronous networks. It speaks the PostgreSQL wire protocol , supports a reasonable dialect of SQL , and combines replication for durability with transparent scale-out sharding for large tables. Its most…

60

Introduction to R Programming

This is a detailed step-by-step introduction to R programming. Starting with the two major reasons to learn R for Data Science, it will guide you through the installation process, and prepare you for the basics of R: arithmetics, variables assignment, data types, functions, and documentations.