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Comment: apples and oranges (Score 5, Interesting) 73

by bennini (#42988029) Attached to: A Tale of Two Databases, Revisited: DynamoDB and MongoDB
We are heavy users of MySQL (Percona) and MongoDB at my work. Recently I have been researching DynamoDB because of a specific use-case. A side project I run uses Google App Engine with Datastore (aka bigtable) for persistence.

Comparing DynamoDB with MongoDB is like comparing apples and oranges. The only thing the two share in common really is the fact that neither supports SQL (and for that reason are called NoSQL databases). Their intended purpose is completely different which is why I found it strange that the author of the original Slashdot story would pit them against each other the way he did.

If DynamoDB is to be compared against another datastore, the most similar alternative would probably be Google App Engine's Datastore/big table.

Similarities between DynamoDB and GAE Datastore
  • both use "schema-less" table structures for storing items (i.e. two items in a single table can have different columns)
  • both support relatively simple primary keys (GAE only allows a single column PK, Dynamo allows a pseudo-two-column PK)
  • both encourage only efficient queries (GAE forces it, Dynamo allows full table scans but they are highly discouraged)
  • both support list properties (a column with multiple string values for example)
  • both are hosted "in the cloud" and scale horizontally almost infinitely
  • both are billed based on reads/writes + total stored data (Dynamo has an extra dimension to cost which is throughput)
  • both have very limited support for referential integrity between items (GAE supports "embedded" entities and recently added basic relationships but nothing like many to many)
  • GAE supports transactions across entities within the same group (i.e. on the same server) and recently added support for XA transactions (tx's across entities in different groups/on different servers). Dynamo does not have transactions but it supports some atomic operations on an individual item like compare and get.

Differences between DynamoDB and GAE Datastore
One major difference between GAE Datastore and DynamoDB is that GAE supports single and multi property indexes while Dynamo does not support indexes at all aside from a table's primary key. GAE datastore supports efficient queries that use the indexes (if you try to run a query that does not use an index it will fail) along with some basic predicates like equality, inequality, greater than and less than expressions, etc. In DynamoDB, if you want an index, you have to build it yourself in a supplementary table.

GAE Datastore Self-Merge Joins
GAE datastore also supports what they call "self-merge joins" which are super powerful. I don't know if any other schema-less datastore has this.

DynamoDB Purpose
The main reason one would use DynamoDB is when they need scalable throughput; in other words, when your needs for write and/or read speeds fluctuate drastically and when you know you will occasionally spike to extremely high throughput requirements. For times when you expect to have huge throughput for writing, you can pay to scale for that small period of time and then you can reduce your costs by throttling down to a more sane limit. You can run MapReduce jobs over DynamoDB tables using Amazon Elastic Map Reduce. And you can also copy a DynamoDB table into an Amazon Redshift "warehouse"; once the data is copied into Redshift you can run efficient SQL queries over it and Redshift can efficiently do that over petabytes worth of data.

MongoDB
MongoDB, on the other hand, is a "schema-less," document oriented database that is good for organizing clumps of information as a single "item" in the datastore. So for example, you can have a single book document which contains nested information about its authors, keywords, reader reviews, and statistics about word usage in the book....all in a single mondodb "record." This is essentially impossible in DynamoDB (unless you do what the previous article's author did by storing an object graph as JSON within a single column but this is kind of misuse). Mongo also provides indexes on properties in those documents (even nested properties) similar to traditional RDMS indexes on table columns. It has very good support for clustering and it's very easy to setup. MongoDB is very fast therefore it is good for applications that intend to be very write-intensive. I believe this is one of the main reasons that people compare it to Dynamo. However, it is easier to scale Dynamo since you don't need to standup any additional servers yourself. MongoDB does not support transactions; operations on a single document are atomic but the database does not provide any native mechanisms for performing an atomic modification to two or more documents (you would basically have to implement 2 phase commit yourself). MongoDB has a powerful query language based on javascript/json but personally, I find it extremely painful to use compared to SQL.

For the TLDR-crowd:

  • GAE datastore is a great mix of schema-less design, denormalized datasets + self-merge-join + some RDBMS functionality like indexes and SQL style queries with predicates
  • DynamoDB is for systems that need the ability to scale reading/writing throughput to very high levels, on demand. It is pretty low-level in terms of features and datatypes and creating indexes are up to the user. Great integration with other AWS tools.
  • MongoDB is great way for easily storing and retrieving object graphs (represented as JSON) with great read/write performance and some RDBMS functionality like indexes and queries with predicates

I am not familiar with CouchDB but I think it would belong in the MongoDB family.

Comment: Re:Or the reverse (Score 1) 899

by bennini (#42741165) Attached to: New York Pistol Permit Owner List Leaked
I agree that the TSA is worthless. And it was created by a Republican who supposedly believed in smaller government.
But owning more guns isn't going to make the TSA going away.

It sounds like you want to justify guns for fear of our government turning into North Korea.
Sorry, but I think voting is a better deterrent for that than guns.
Most other civilized countries in the world do not allow regular people to own guns and they are not turning into totalitarian regimes. It would never happen in America. If you think it can, you've watched too many movies. And even if it did, then pistols and rifles in the hands of a bunch of untrained gun fanatics aren't going to prevent it. Our freedom is not sustained by guns, it is sustained by other values.

Video games and movies don't make people violent. Getting bullied at school, broken families, poverty, lack of family values, and mental disorders cause people to be violent.

Your theory that people will kill even if they don't have "advanced weaponry" is pretty ridiculous.
If you have an AR15 , and I have a knife, which of us has a higher chance of taking out 20 people in a movie theatre?

Honestly, who cares if there are other ways to kill people. Sure I can drive over a person crossing the street. I can put poison in their food. I can strangle them from behind. The objective is to reduce deaths caused by bullets ripping through a person's flesh and bones. If you reduce the number of deaths by one by banning guns, then you have improved society.

Comment: Re:Or the reverse (Score 1) 899

by bennini (#42702153) Attached to: New York Pistol Permit Owner List Leaked
Your "solution" does nothing to prevent another newtown. A passive approach where you punish someone after breaking the law only makes sense for non violent crimes. Violence, and most especially gun violence, needs to be preempted and prevented.

There are two ways of doing this.
1. Identify people who are violent or potentially violent
2. Reduce the chances that a violent person will successfully kill others if he/she fails to be identified by 1.

Obviously 1 is much harder than 2. Getting rid of guns is the easiest solution to 2.

Comment: Re:please think of the children (Score 1) 899

by bennini (#42644767) Attached to: New York Pistol Permit Owner List Leaked
well if you are going to get technical about it.... the bullet ripping through the victims flesh, bone and organs followed by the ensuing loss of blood kills them.
the idea that the assailant may simply try a different weapon if he doesn't have access to a gun doesn't really hold much water. a gun leaves a victim with essentially no possibility to resist death. if the attacker were using a hammer or knife or banana, the victim would have a much better chance of survival.
in short, yes, guns kill people. the fact that you fail to accept this does not mean it's not true.

+ - New York Pistol Permit Owner List Leaked->

Submitted by Anonymous Coward
An anonymous reader writes "On Friday, The Journal News caved under pressure of gun advocates and shutdown the interactive maps which contained the names and addresses of licensed gun owners in upstate New York. The maps are still visible on the site however they are simply static images. The Journal News published the interactive maps on December 23 which caused significant backlash.

In a similar move, Gawker published the names of licensed gun owners in New York City without addresses.

New York state Senator Greg Ball (republican) called the removal of the data a "huge win."

On Saturday, an anonymous user leaked the raw data used to build The Journal News maps."

Link to Original Source

Comment: Re:Gun control != taking guns away (Score 1) 2987

by bennini (#42296961) Attached to: 27 Reported Killed In Connecticut Elementary School Shooting
<quote>A toddler died because his mother was an idiot and let him stand on a ledge at a zoo. Where is your outrage over those deaths?</quote>
Your arguments would make more sense if a parent's decision to lock their baby in the car resulted in the death of 27 people.

<quote>Why don't we try to help the nutters before they kill our children?</quote>
Because in practice it is is much harder to control a person's will, mental state and 20-year upbringing than it is to control the guns and ammunition that he has access to.

<quote>Since alcohol doesn't benefit society, should we bring back prohibition for the safety of the children?</quote>
No, a gun with a 9 bullet clip has the potential to cause much more damage than a drunk driver.

If gun fanatics are so intent on having guns, then we should simply restrict ammunition sales and only permit gun clips that hold 1 bullet.

Comment: My experience w/ Invision Power, Jive & vBulle (Score 1) 259

by bennini (#41953073) Attached to: Ask Slashdot: What Is the Best Way To Add Forums To a Website?
I use Invision Power for my website: http://www.styleguise.net and it works very well. My website is comprised of two components: a marketplace that I wrote from scratch using GWT + App Engine and a forum component which use the commercial off the shelf Invision Power suite. I have single sign on between my two applications as well.

IPBoard (the forum application from Invision power) is highly customizable. You can write a login module for it to integrate with any identity management system. It is written in PHP so you will need to develop your extensions in PHP also.
They also offers a traditional content management system called IPContent. It works pretty well once you figure out how things are laid out. The index/splash page for my site is simply a page served by the IPContent component.

I am a member on several forums that use vbulletin. One of them recently migrated to Huddler which I do not recommend at all. The other is still using a very old version of vbulletin. The their migrated to Invision Power. Invision Power seems to release more often and have better features than vbulletin.

Another option to choose if you have more money to spend is Jive. My company uses it for our customer facing forum system and also internally for content management.

If you have additional questions feel free to ask.

Comment: Square peg....round hole (Score 5, Insightful) 122

by bennini (#39555143) Attached to: More Fuel For Facebook Censorship Advocates In India
The article states that a young man posted a photo on Facebook which offended several people.
Several of those offended people decided to protest peacefully in front of a police station demanding his arrest.
Other people decided to protest violently by burning cars, smashing in window stores and just generally acting like idiots.
Instituting a nationwide internet censorship policy won't address the problem: impulsive, destructive people whose first course of action is violence.

Comment: what else do you expect..... (Score 1) 267

by bennini (#34504794) Attached to: EasyDNS Falsely Accused of Unplugging WikiLeaks
when the government system that is in place to protect the people fails, the only recourse left is to revolt. this is simply a "digital revolt" which is different from what people are normally accustomed to. traditional "physical protest" (i.e. forming a chain of people in front of the entrance to a store, marching down a road etc) almost always disrupts standard business practices or day-to-day activities. It sounds like you expect a protest/revolt to not inconvenience anyone.

additionally, the organizations that pulled support from wikileaks were the first to demonstrate lack of due process. they referenced SLA agreements about "wikileaks using their services for illegal activities" long before illegality had even been proven.

regardless, the mob's activities pale in comparison to the civil liberties that are currently being trampled upon by the government. in that respect, they may be somewhat justifiable.

Comment: People in the middle east already deal with this (Score 2) 728

by bennini (#34468342) Attached to: A Nude Awakening &mdash; the TSA and Privacy
For countless years, people in Iraq, Afghanistan, Palestine, Lebanon, Pakistan, India, etc have been dealing with bomb, IED and explosive threats. Countless people have died at the hands of these terrorist attacks. The people in those countries make the choice every day to live their lives normally...in the face of not having any of the "security" mechanisms that we have. They have not chosen to trade human rights for "safety." In this sense, they are already free-er than us.

Comment: Re:Don't bash AT&T (Score 2, Insightful) 420

by bennini (#30568088) Attached to: Consumerist Says AT&amp;T Site Won't Sell iPhone In NYC, Citing Network

it's not any different than a restaurant declining to take a reservation because they're full. Respectable businesses do this all the time. It's perfectly reasonable.

If AT&T is either unwilling or unable to provide network support to keep up with consumer demand for the iPhone, then their exclusivity deal should be nullified. I'm surprised the contract they signed with Apple does not include some provisions for dealing with this sort of situation.

This is exactly why exclusivity deals are bad. People in NY are now stuck with either buying an iPhone and having shitty service or not buying an iPhone.

"In matrimony, to hesitate is sometimes to be saved." -- Butler

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