mslot

16 ms·

121.
by mslot 10y ago
But what if you need to partition and possibly scale out part of your database? At that point a normalized data model becomes a huge road block. A balanced approach to normalization often allows you to more adaptive to requirements. If poss
122.
by mslot 10y ago
I assume Alpha Go has been trained using a large number of games played by Go masters so the games it played itself probably won't provide much more information, unless it can learn its own weaknesses from those games.
123.
by mslot 10y ago
WhatsApp came to Europe at a time when there was a strong need to replace badly overpriced SMS. In the US most telco's offered subscriptions with free, unlimited SMS and WhatsApp didn't provide any immediate benefit. Facebook Mess
124.
by mslot 10y ago
Literally most countries in the world: http://www.techtimes.com/articles/160897/20160525/top-messag... Sure, I have messenger and hangouts and telegram as well, but WhatsApp is like a primary mode of communic
125.
by mslot 10y ago
I don't believe that humans take split-second (binary?) decisions based on morality, only survival. Most of the time, people's instinct tells them to get off the road if there are no alternatives. This actually seems like a reason
126.
Hacker News is down via IPv6(twitter.com)
2 points by mslot 10y ago|0 comments
127.
by mslot 10y ago
Reads do involve making some network round-trips, but it's only a few milliseconds and there's no specific throughput limitation. Write throughput is limited by network latency. There is also a relaxed consistency mode in pg_paxos
128.
by mslot 10y ago
Paxos provides strong consistency and can proceed even if some nodes fail. 2PC has intermediate states in which a transaction is only partially committed, and all nodes need to be available to perform writes. The downside is that Paxos&#x27
129.
by mslot 10y ago
Once a query has been logged there's no turning back. The problem with transactions is mainly that Paxos is fundamentally incompatible with read committed mode. It is technically possible to log a multi-statement transaction as a singl
130.
Show HN: Interactive Analytics on GitHub Data Using PostgreSQL with Citus(citusdata.com)
7 points by mslot 11y ago|0 comments
131.
by mslot 11y ago
Yes, Citus may be a good fit, for a complete example see: https://www.citusdata.com/blog/15-marco-slot/402-interactive...
132.
by mslot 11y ago
(Marco from Citus Data) > If I use CitusDB as an analytical database, then it's comparable with Redshift, Hive etc. A particular difference is in response times and concurrency. Data warehouses and Hive are great for reporting use-c
133.
by mslot 11y ago
(Marco from Citus Data) It seems at least theoretically possible. Since the Citus master executes distributed queries by sending regular SQL queries to the Citus workers, you could already use BDR servers as workers and replicate the data b
134.
by mslot 11y ago
I developed something similar for my PhD thesis, which works in a decentralized way using an ad-hoc network: http://thesis.marcoslot.net/merrion.htm (press play, you can click cars and enable visualizations) The system anal
135.
by mslot 11y ago
Awesome, would be even cooler if it could pick up specific features like faces and replicate the style. Now it kind of brushes over most faces unless it dominates the picture.
136.
by mslot 11y ago
Bucardo provides asynchronous (eventually consistent) replication. If you need strong consistency with fault-tolerance, you need something like pg_paxos, but it comes at a significant performance penalty so it's not really an alternati
137.
by mslot 11y ago
I can't really give an overview, but I'll tell you what I know :). Paxos is a rather simple algorithm for reaching consensus on a value once: http://research.microsoft.com/en-us/um/people/lamport&#x2
138.
by mslot 11y ago
I've written something similar for PostgreSQL using Paxos: https://github.com/citusdata/pg_paxos . It can replicate tables across a set of PostgreSQL servers. pg_paxos is an extension that uses PostgreSQL's q
139.
by mslot 11y ago
disclaimer: I work for Citus Data The bottleneck is usually not I/O, but computing aggregates over data that continuously gets updated. This is quite CPU intensive even for smaller data sizes. You might want to consider PostgreSQL, wit
140.
by mslot 11y ago
pg_paxos is brand new and while the current release is reasonably stable and tested under various failure scenarios on EC2, it's also lacking in some areas, especially performance (think 10-100 writes/s). We will continue developi
141.
by mslot 11y ago
Added a license file (PostgreSQL license).
142.
by mslot 11y ago
I would guess that the majority of Facebook's mobile traffic is through their app.
143.
by mslot 11y ago
Interesting! The examples show a single master and single slave, but etcd blocks when half or more nodes die. How does Spilo deal with that?
144.
by mslot 11y ago
CAP is a simple and obvious principle: If you have a partition, meaning you cannot always meet your read/write quorums, you can choose: - availability: always accept writes, but reads in other partitions might not see them so there&#x2
145.
by mslot 11y ago
The problem with joins and reason why most distributed databases don't support them is primarily that the local machinery is complicated to implement. Given local join machinery, a join between 2 distributed tables can be achieved by j
146.
by mslot 11y ago
For basic reads and writes the FDW APIs are quite suitable and they work well for cstore_fdw. However, to get the most out of columnar storage you also need vectorized execution that can calculate aggregates on blocks of values. The FDW API
147.
by mslot 11y ago
Our economy has reached a point where it's becoming so harmful to the environment it exploits that it's causing a mass extinction, an event that hasn't occurred for 250 million years. On the timescale of a few decades, things
148.
by mslot 11y ago
Joining a large number of tables is a sweet spot for PGStrom where in which there are a lot of parallelizable computations. For a lot of queries it can actually be slower.
149.
by mslot 11y ago
Ah true, I should have probably written "all round 1 participants". It can be enforced by the receiver as well. There are some other implied receiver-side steps that I did not write down, such as rejecting all proposals with a seq
150.
by mslot 11y ago
Paxos is one of the simplest distributed algorithms out there. For a proposal i with value x: 1. Ask everyone not to participate in proposals older than i, get a majority to agree and send back any previously accepted values. 2. Ask everyon

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