computer express

Less than a week left until the android hackaton in St. Petersburg. Next weekend is the incredible number of developers get together and kodyat two days with short breaks for sleep, food and fellowship with each other. End this crazy weekend with presentations of prototypes and rewarding. Winners will receive prizes from Acer, the General partner DevCamp'and in St. Petersburg, but also from Beeline, Sony Ericsson and O'reilly. To participation are invited not only developers, but designers, designers of interfaces, testers, and indeed all interested persons. Calendar of events to 18 Feb the the 10:00-10:30 — registration of participants, coffee-break the 10:30-11:00 — presentation of the partners and organizers the 11:00-12:00 — brainstorming, discussion of ideas, formation of teams the 12:00-14:00 — work on projects the 14:00-15:00 — lunch the 15:00-18:00 — working on projects the February 19 the the 10:00-10:30 — coffee-break the 10:30-13...

Since last post on the visual poiskovoy Search me she has a new function mediapoisk and collections ( Stacks ). The video search is not new (although its continue to invent ), but the ability to flick the mouse to create galleries of interesting. Prior to that, the features of the search engine was only in the visual representation Cover Flow (I think I added the outline around the words of the query in the screenshot) and the assumption category, due to the lack of which in the normal search you have to add the exception. the And Yes, AdBlock still blocks Searchme, but only screenshots of sites, so you have to add an exception "@@searchme.com". the Stacks Stack — a collection/folder of links to the found pages, videos and images that are displayed in the same gallery (but in the order they were added, which you can then change it via the box in the corner of the slide). With collections, as it turned out, work very convenient to take the picture and drag ...

on may 11-12 of this year in Moscow will host the third conference of professional programmers Application Developer Days (ADD). What you need to know about the conference ADD someone who it was not? First, what is a conference about technology, about programming languages, libraries, tools, architecture solutions and complex projects. There are almost no reports about people management, about effective methods of manual search and error about ways of convincing the customer that there are no errors and everything goes according to plan. Despite the importance of such reports for the industry as a whole, for the programmer, they are boring. Imagine how all the lights Agile you develop the dispatcher ATP on FoxPro... Definitely some things you can't imagine. Second, the Application Developer Days is, of course, the conference isn't for everyone. If you do develop arm on FoxPro and plan to pursue it further, then ADD this is not your case. You are concerned about the ...

In the course of interaction on the social sites all network members communicate writing topics, respond to comments. The most interesting interlocutors added to the friends and their messages get to a personal feed. While the growth of the number of messages becomes increasingly difficult to determine with whom to communicate. With someone can be quite active to write in different themes, but because of the large amount of information not just to associate different messages with one person. has Long been known that people, regardless of their analytical skills faster and better perceive information in graphical form. But now, in order to determine how close their views with the opinion of another member of the community is necessary to perform a lot of messages or to act impulsively relying on memory and an instant decision. Therefore, I propose to implement on Habrahabr visualize the social relations between abrollsoftware. This will make it easier to find like-minded peop...

1 March was the first Moscow Django Meetup . 25 people — experienced developers and those just beginning — he listened to three reports and met other gangitano. The community is primarily a communication, so the meeting began with the fact that all who came were told about themselves. 25 people gathered the first MoscowDjango, 6 people called themselves experienced developers ("Yes, I'm on django with 0.9 x versions! :-)"). Many other shy and began his greeting with, "Well, if anyone here is a novice, it's me...". Among the attendees were corporate developers, and freelancers, and startups, experts Ostrovok.ru, polit.ru, RussiaToday and other companies. First with a story about a magazine layout out Alexei Dubkov. He did a great report on how using a simple app in django to make the presentation of the material on the website more beautiful and interesting. After Alexei Vladimir Epifanov (Ostrovok.ru) told about the console , without which w...

did you Know that the name Wagner is not only famous Opera famous composer? And whose name known to every student reaction silver mirror ? What will happen with acetaldehyde in acidic and alkaline medium? We have tried to give you the answer to this and many other issues. Now, anyone interested in chemistry can learn from what makes polyethylene that can get of acetone, and even how to cook life-giving euthanasia . We made sure to provide the results not only the reaction, but its name, and also links to more detailed information in Wikipedia or in other reference books. a Little about what constitutes Nigma-Organika Hand in its development, we studied all available products on the market, bitterly sighed, and started from scratch, as everything that existed at that time did not satisfy us a little more than perfect. So we had to create some completely unique components. First, we did analyzer the query string that allows you to enter substances to searc...

Start with a description of ifttt.com ifttt.com is a very promising startup that in a nutshell: Lets You Hack Together Web Apps, Without Coding Skills . If more, it is a service that allows users, without diving into the API a huge amount of services and any knowledge about the development\programming languages mix and automate various activity with each other. In early 2012, received a seed investment in the amount of $1.5 M . In the system of only a few entities, such as tasks ( these are the rules of your triggers or reactions to an external event), recipes (these are the tasks that others have created and shared with all) and channels ( that's what it takes to try to confuse establishing different patterns of tasks, each channel should be tied to ifttt.com ). Screen task looks like this preamble: what goals we should pursue? I think nobody needs to explain the reasons for which social presence and most importantly — an adequate social activity, ...

At the moment, the load on the servers, Twitter has grown to 1,000 TPS (tweets / sec) and 12,000 QPS (queries per second) — more than 1 billion queries per day. The current infrastructure still stands, but to create a reserve for the next few years, the company has decided to update a backend for a search engine. "If we worked well, you weren't supposed to notice anything in the last week," reported the blog developers Twitter. Until recently, search the backend of Twitter was based on the old SQL system from the company Summize. Her bought in July 2008 for this purpose, and took five of six developers. The need to upgrade Twitter became clear immediately after the presentation of iPhone 3G, and then began a collaboration with Summize. But now it's time to upgrade again. About six months ago, it was decided to develop a new, modern search architecture based on efficient inverted index instead of a relational database. Because Twitter loves open source,...

Full contents and a list of my articles on search engine will be updated here . In previous articles I talked about the work of the search engine here and came to a difficult technical point. Let me remind you that there are 2 types of indexes – direct and reverse. Direct – mapping document a list of words it encountered. Opposite – word is mapped to a list of documents in which it is. Logically, for a quick search of best suited opposite the index. Interesting question and in what order in the list of documents to be stored. In the previous step from the DataFlow module, the indexer, we got a little piece of data in the form of direct index, the reference information and information about the pages. Usually I have it around 200-300mb and contains about 100 thousand pages. Eventually, I abandoned the strategy of storage of whole direct index, and store all of these pieces + full reverse index in several versions so you can revert back. The device index to look at, simpl...

Idea, which formed the basis of this service, simple and, I hope, will be in demand by the Internet masses. In short, the essence in the following. This project helps people quickly find assistants, teachers, nurses, promoters, couriers, handymen and other professionals, to assist you in your urgent (or not) businesses for a fee. a few examples Imagine, you need to repair the plumbing, and mechanic of utilities will not wait. What are the alternatives? Look for a locksmith using Yandex/Google? A better way: However, plumbing is not every day change. Example easier You woke up on Saturday and found the last bottle of beer in the fridge... opened it pshshsh... and I realized... well, not you will go in the next couple of hours after yesterday's on the street, to buy something necessary, as in the above the refrigerator mouse hanged. You can suffer, you can: It's simple: open the website www.karta-del.ru , find your house on the map, creat...

bring to your attention the result of six years of experiments — the search engine "Butty" So was to begin a post with a PR of my engine 2 years ago. A post was already written and ready to publish, but did not work :) Under the cut are waiting for you lyric story of the creation and attempts to promote. Birth the Idea of creating this search engine came into my head in the day of my age. On the same day (2007.08.19) had registered the domain in the zone .EN The establishment of symbiosis search engines at that time already was not new, for example, the search engine Nigma held 0.4% of Russian-speaking search. I called Google and said, whether they admit the combination of issue. The answer was positive. So, for a few months a friend the programmer had written code for a little money. For little money I got unoptimized code, as expected. Further, during the year, we advertise our search engine forums, web-masters, to listen to the opinions ...

Decided to describe in my opinion the most useful tree structure. AVL tree is a binary tree (each vertex is not more than 2 sons) in which each vertex has an identifier (and keeps the tree), identifiers obey the following rule: the left son ID<ID of the parent<ID right son. Ie if you traverse a tree recursively from left to right will get sorted in ascending order the list of ID from right to left in descending order. Moreover, the wood is balanced: the height of the left subtree differs from the height right high for 1. I wonder what it means then to check existence of element in the tree takes log(N) N – number ID. It is necessary to go from the root down, and because the tree is maximally symmetric then its height is log(N)+1 The good news is that we're allowed to attach to the top any more useful data and then selection of arbitrary data by ID will take log(N) time. The bad news is the same ID as follows from the definition it can not exist. Will have to...

After was launched the city portal of public transport of Saint-Petersburg and installed transport monitoring systems GLONASS/GPS was made possible something that previously could only dream of — coming to a stop to look at where we are right now is the bus that we wait. And "right now" is not just a figure of speech, no exaggeration. Transport really is displayed on the map in real time. Of course, a view of the map on a mobile device. Free software "Spb Transport Online" exists in two versions — for Android and Windows Phone. Despite the different interface, they are very similar in terms of ease-of-use — run, the GPS determines where we are and use the button to select the desired type of transport. The result in the picture above (clickable). Blue, green trolleybuses, and trams — red. example applications the the You are standing at the bus stop at 12 at night waiting for the tram. Are there trams? And if you have to, it is left on the line...

Company Postgresmain" organizing Committee the conference Highload++ are pleased to present to your attention a master class "How to design a scalable architecture PostgreSQL" , which will be conducted by the experts of the company Skype ASKO Oy (Asko Oja) and Marco Creen (Marko Kreen) . The event will be held on 8 October 2008 in Moscow in conference-center "InfoSpace" . "A master class from the developers of Skype will complete a three-day series of PostgreSQL events that we will hold 6-8 October, — says the Executive Director of the company "Postgresmain" Nikolay Samokhvalov . — In the evening of the 6th of October we will organize the next, the fourth open meeting of the Russian community of users of PostgreSQL with the participation of foreign guests. 7th all visitors of the conference Highload++ will be able to listen to an interesting series of reports focused on those using or starting to use PostgreSQL together with our foreig...

Postgresql, no doubt, a great DBMS. She possesses extensive capabilities, excellent documentation, and is free. However, there will always be something that the user is not to be missed. In postgresql this is easily fixed, because it allows you to create functions in languages for every taste, whether Plpgsql, Perl, or even Java. Here is an example. I always lacked functions that get the DDL selected table. In oracle, for example, you can use the resources of the dbms_metadata package. But in postgresql counterpart. It is possible of course to use pgdump, but this is a little something I would like to have a database. And so on, I think everyone can find a few of these little "list". In my every database I create in the schema "public" to a certain set such that to facilitate my life functions. In this topic I want to share them. I invite all to share in the comments your experience. the Array to table With an array of work is not always easy, of...

Organization the Common Crawl made a generous gift to developers and companies working in the field of search and information processing. In the open access on Amazon S3 posted an index of 5 billion web pages with metadata, PageRank and count the hyperlinks. / > If you saw in the logs of the web server CCBot/1.0, that is their crawler. Non-profit organization Common Crawl is in favour of freedom of information and aims to make publicly available search index, which will be available to each developer or startup. It is expected that this will lead to the creation of a whole galaxy of innovative web services. Search cluster Common Crawl running in Hadoop, data is stored in HDFS and processed through MapReduce, and then all the content is compressed in format files ARC , files, 100 MB (total base 40-50 TB). You can download a file to yourself or directly processed on EC2 using the same MapReduce. Access bucket 'the only possible flag Amazon Requester Pays, that is f...

The Pravomer.ru it has been two years. April 19, 2010 released article on habré , announced the launch of the project. You can evaluate the results, and the failure of the project during this time. the Statistics In two years, the site was visited 34200 unique visitor. Of them signed up 450 people. 75% Muscovite, 6% in St. Petersburg. The first peak was when the article was published on Habre, and the second in September 2011, when the site added to the directory best-links.net.ru . All were added 126 quotes. Of these, only 23 participants of the project (the rest was added by myself). Currently tested 65 citations, of which 34 — the truth (or the prediction has come true), 23 lies, and 8 — removed from the check. In ranking the truth turned out to be 6 people, liars — 9. The absolute leader in the first rating was Putin have a 20 "truthful" quotes & 6 "false". It is followed by the economist Mikhail Khazin (5 quotes — true and 1 f...

this weekend in the wonderful city of Vologda will be held 8 media art festival " Multimatograf ". Every year he brings joy to residents and all who come to see the work of participants from around the world and learn from master classes by leading experts in their field. The main event of the festival educational program, exhibition, different shows and a gala concert. This year it was sent to 183 work, which is a new record (last year it was 150). Geography: Russia, Belarus, Ukraine, Armenia, UK, Austria, Iran, Taiwan, France, Venezuela, Estonia. Just passed preselekt 105 works: 50 cartoons, 15 clips, 15 short films, 14 works in the "Wild" and 11 in "Video art". The total time of all work 9 more hours ! The jury noted the good quality of work, and a large presence of "Kote" :) upd: why so many minuses? Would write though... It is known that by tradition the festival Georgiy Molodtsov (Director, lecturer Institute of Cinemat...

Search engines, including Google and Yandex, to overoptimize sites. Search engines are constantly working to ensure that such sites are not particularly highly ranked. Recently in the Network appeared the news that Google is working on a new system of penalties for similar sites. There is even an audio recording of the discussion methods of assessment overoptimize sites involving the infamous Matt Cutts (Matt Cutts). If anyone's interested, the record can be downloaded here on this Silke . According to the participants of the discussion that we need to "raise the bar" for evaluating websites. This can ensure that sites with good content, but an intermediate level of optimization will still be ranked above sites with no quality content, but good optimization. Cutts noticed that usually the development team of Google search announces planned changes. But now the developers have decided to announce the changes over which Google has been working for several ...

this weekend, Kiev will host a very cool event Garage48 — the idea is that for two days to create a startup. In the “create “ includes everything needed to present your business idea, qualify, technically, to bring it to life, and then be able to sell it to strict spectator and wise mentors. This event was invented in Estonia and has already managed to visit many countries of the world. Finally, Garage 48 has reached the Ukraine: from 11th to 13th may we occupy the Library of KPI , which is located on the Avenue Victory 37 and start enjoying foreign mentors (they will guide you in the right direction to create a startup and guide you on the right path, if you go into the jungle), as well as the company of their colleagues and event organizers — representatives of Garage48 Foundation And IT DOU-activist Vicky Zorbas. On Friday we will get acquainted with the ideas of the participants, will select the best ideas and form teams. Saturday morning will see which team surv...

Google launched the service "Trust (trusted) shops" in test mode. The first news about this service appeared a few months ago, and now "Trusted Stores" has already started to work. According to the plan, the new service is an addition to AdWords, when in the published ads will show the status of some companies. the Company will only be validated after the submission of an application. The rules of this service is simple — you need to apply and provide to the Corporation are required to check the data. If all is well, the company is given the appropriate status and your AdWords ad, this status is visible to potential customers. Of course, this status will make customers more trust than in the case of conventional ads. The icon "Trusted Stores" will serve as a confirmation that a company that is interested in the client, it is reliable and can be trusted. To check companies will use several criteria, including the quality of service delivery an...

next article "Unique key in a distributed database" . We have a database which we want to share. Ideally, I want to do master-master. One of the most difficult moments, is to ensure the uniqueness of keys on all servers. And well if the database was originally designed for scaling... Again, this is something from the realm of the ideal, which is, let's just say not often. So we have a base which is necessary to prepare for synchronization of master-master will make all keys in our database are unique within a project. The article has considered several options, but we will focus on one proposed Instagram Step 1 — Translate all keys in bigint The implication here is that all our primary keys are named id and fields respectively which refer to these keys named like this: order_id, client_id, table_id, Create a function which translates the integer bigint the DROP FUNCTION IF EXISTS "field_int2big" (field text, tablename text, table_s...