1
New
The latest blog posts to take off on Hacker News. 63 posts.
2
Knossos: Redis and Linearizability
A few weeks ago I criticized a proposal by Antirez for a hypothetical linearizable system built on top of Redis WAIT and a strong coordinator. I showed that the coordinator he suggested was physically impossible to build, and that anybody who tried to actually implement that design would run into serious problems. I…
3
Call me maybe: Redis redux
In a recent blog post , antirez detailed a new operation in Redis: WAIT . WAIT is proposed as an enhancement to Redis’ replication protocol to reduce the window of data loss in replicated Redis systems; clients can block awaiting acknowledgement of a write to a given number of nodes (or time out if the given threshold…
4
MySQL 5.7: over 1M queries/sec on a single machine
Last week, during Tomas ' keynote at MySQL Percona Live Conference in London we announced as one of "previews" of the following MySQL 5.7 release(s) -- an over 1,000,000 Query/sec result obtained with InnoDB Memcached plugin on a Read-Only workload. This article here is just to confirm the announced results without…
5
How Python became the language of choice for data science
Nowadays Python is probably the programming language of choice (besides R) for data scientists for prototyping, visualization, and running data analyses on small and medium sized data sets. And...
6
7
How to make fake data look meaningful
If you are trying to trick somebody with your data, never share the raw data; only share the conclusions. Bonus points if you can’t share the data because it is somehow priviledged or a trade secret. The last thing you want is to allow other people to evaluate your analysis and possibly challenge your conclusions.
8
Modelling a Basic Income with Python and Monte Carlo Simulation
Basic Income is a popular policy floating around the internet lately. The idea consists of declaring that the government will pay each living adult a fixed amount of money every month - an amount comparable to a minimum wage job. This policy would then replace all current welfare programs - welfare, unemployment …
9
MongoDB is to NoSQL like MySQL to SQL - in the most harmful way
MySQL and MongoDB are both popular, yet poor representatives of their species
10
11
The Big Data Brain Drain: Why Science is in Trouble
Update, August 2014: see Hacking Academia , my most recent reflection on this subject.
12
Hstore development for 9.4 release
I returned back home from PGCon.EU-2013 conference, Dublin, Ireland, where we gave two talks - Next Generation of GIN and Binary storage for nested data structures and application to hstore data type . These projects as well as visiting the conference (I, Teodor Sigaev and Alexander Korotkov) were…
13
Principal Component Analysis for Dummies
(I recently wrote a new post that you may also find interesting called Principal Component Analysis 4 Philosophers) Having been in the social sciences for a couple of weeks it seems like a large am…
14
15
Bloom Filters by example
A Bloom filter is a data structure designed to tell you, rapidly and memory-efficiently, whether an element is present in a set.
16
Intro to Pandas data structures
Part one of a three part introduction to the pandas library. Geared towards SQL users, but is useful for anyone wanting to get started with pandas.
17
18
19
The trouble with timestamps
Some folks have asked whether Cassandra or Riak in last-write-wins mode are monotonically consistent, or whether they can guarantee read-your-writes, and so on. This is a fascinating question, and leads to all sorts of interesting properties about clocks and causality.
20
21
22
23
Call me maybe: Cassandra
Cassandra is a Dynamo system; like Riak, it divides a hash ring into a several chunks, and keeps N replicas of each chunk on different nodes. It uses tunable quorums, hinted handoff, and active anti-entropy to keep replicas up to date. Unlike the Dynamo paper and some of its peers, Cassandra eschews vector clocks in…
24
Command-line tools for data science
Blog article by Jeroen Janssens. Sep 19, 2013. 21 min read. Data science is OSEMN (pronounced as awesome). That is, it involves Obtaining, Scrubbing, Exploring, Modelling, and iNterpreting data. As a data scientist, I spend quite a bit of time on the command-line, especially when there’s data to be obtained, scrubbed…
25
Don't use Hadoop when your data isn't that big
"So, how much experience do you have with Big Data and Hadoop?" they asked me. I told them that I use Hadoop all the time, but rarely for jobs larger than a few TB. I'm basically a big data neophite - I know the concepts, I've written code, but never at scale.
26
27
28
PostgreSQL Basics by Example
Connecting to a database 1 2 $ psql postgres # the default database $ psql database_name Connecting as a specific user 1 2 $ psql postgres john $ …
29
NYC has released data for every tax lot in the city. Here is my first look
Many thanks to advocates inside and outside who worked tirelessly for years to liberate one of New York City’s most fundamental datasets. Many more thanks to the efforts of Department of City Planning, DoITT, and the Chief Analytics Officer’s office. THANK YOU!
30