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Here are PDFs of the slides of the lectures so far: [[attachment:SearchEnginesWS0910/lecture-1.pdf|Lecture 1]], [[attachment:SearchEnginesWS0910/lecture-2.pdf|Lecture 2]]. | Here are PDFs of the slides of the lectures so far: [[attachment:SearchEnginesWS0910/lecture-1.pdf|Lecture 1]], [[attachment:SearchEnginesWS0910/lecture-2.pdf|Lecture 2]], [[attachment:SearchEnginesWS0910/lecture-3.pdf|Lecture 3]], [[attachment:SearchEnginesWS0910/lecture-4.pdf|Lecture 4]], [[attachment:SearchEnginesWS0910/lecture-5.pdf|Lecture 5]], [[attachment:SearchEnginesWS0910/lecture-6.pdf|Lecture 6]]. |
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Here are PDFs of the exercise sheets so far: [[attachment:SearchEnginesWS0910/exercise-1.pdf|Exercise Sheet 1]], [[attachment:SearchEnginesWS0910/exercise-2.pdf|Exercise Sheet 2]]. | Here are .lpd files of the recordings of the lectures so far (except Lecture 2, where we had problems with the microphone): [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-1.lpd|Recording Lecture 1]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-3.lpd|Recording Lecture 3]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-4.lpd|Recording Lecture 4]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-5.lpd|Recording Lecture 5 (no audio)]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-6.lpd|Recording Lecture 6 (with audio for a change)]]. |
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Here are your solutions and comments on the previous exercise sheets: [[SearchEnginesWS0910/ExerciseSheet1|Exercise Sheet 1]]. | Here are PDFs of the exercise sheets so far: [[attachment:SearchEnginesWS0910/exercise-1.pdf|Exercise Sheet 1]], [[attachment:SearchEnginesWS0910/exercise-2.pdf|Exercise Sheet 2]], [[attachment:SearchEnginesWS0910/exercise-3.pdf|Exercise Sheet 3]], [[attachment:SearchEnginesWS0910/exercise-4.pdf|Exercise Sheet 4]], [[attachment:SearchEnginesWS0910/exercise-5.pdf|Exercise Sheet 5]], [[attachment:SearchEnginesWS0910/exercise-6.pdf|Exercise Sheet 6]]. Here are your solutions and comments on the previous exercise sheets: [[SearchEnginesWS0910/ExerciseSheet1|Solutions and Comments 1]], [[SearchEnginesWS0910/ExerciseSheet2|Solutions and Comments 2]], [[SearchEnginesWS0910/ExerciseSheet3|Solutions and Comments 3]], [[SearchEnginesWS0910/ExerciseSheet4|Solutions and Comments 4]], [[SearchEnginesWS0910/ExerciseSheet5|Solutions and Comments 5]]. = Exercise Sheet 6 = The recordings of all lectures are now available, see above. Lecture 2 is missing because we had technical problems there. To play the recordings (it's .lpd files) you need the Lecturnity Player. [[http://www.lecturnity.de/de/download/lecturnity-player|You can download the player for free here]]. |
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= Exercise Sheet 2 = Here are the details about the three servers (UDP, TCP, HTTP) for Exercise 4: All three servers are running on our machine vulcano.informatik.uni-freiburg.de (IP address is 132.230.152.135). The UDP server is running on port 8888 of that machine. You can send it a number and it will then send you back that number of bytes, in packets of 1000 bytes each. (That means you also have to read packets of 1000 bytes each.) The first ten bytes of each packet contain the packet id. That is interesting for checking which packets get lost and in which order packets arrive. The TCP server is running on port 9999 of that machine. You can send it a request of the form GET /<number of bytes> HTTP/1.1, or you can just use a downloading program like wget or curl and time it. The HTTP server is running on port 80, as web servers normally do. Just download the file http://vulcano.informatik.uni-freiburg.de/file_100M and measure the time. For measuring your transfer and error rates, as requested by the exercise, repeat your experiments several times and also at different times, and form the average of these measurements (or report several numbers if you get very different results). You should ask for large amounts of data, like 10 MB or 100 MB. [[SearchEnginesWS0910/ExerciseSheet2|Here you can upload your solutions for Exercise Sheet 2]]. |
[[SearchEnginesWS0910/ExerciseSheet6|Here you can upload your solutions for Exercise Sheet 6]]. |
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To all: Please note that (almost) everybody will get +2 points for Exercise Sheet 1 (previously I did not assign any points to the first and the last problem). '''Marjan 31Oct09 10:03''' | Notice about Problem 2: You should use precise timers when measuring the running times. If your collection is very small and you round up your times, it's easy to get 0 ms when merging or scanning the inverted lists. I recommend using microsecond scale. '''Marjan 29Nov09 16:47''' |
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To Triatmoko and Ahmed + all: You obviously haven't created your wiki page. Please go to your link and click "Create a new page" and then "Save changes". You should then upload your solutions there and put the link on the wiki like everybody else did. If it is still not clear please ask some of your fellow students. I don't remember if it is mentioned, but you can skip one Exercise Sheet without losing any points. '''Marjan 31Oct09 09:38''' | To Florian: Yes, you can do anything you want to find those words (as long as you produce the required outputs). '''Marjan 29Nov09 16:44''' |
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Hi, I have some question about my exercise Sheet 1, I saw in my exercise page that my name, my upload solution and code in gray color and other persons in blue color. I try to click my attachment file in my exercise page, and I have some message that there are no attachment. any body know about this issue?because my exercise uploaded on Monday 26oct '''Triatmoko 30Oct09 22:18''' | For exercise 1, should we use one of the methods presented in the lecture to find all words in the collection with the prefixes or can we do just anything to get them (though it might not be as efficient)? '''Florian 29Nov09 03:51pm''' |
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Hi Björn + all: For Exercise 4 from Exercise Sheet 1 you had to write code that is at least able to process 2-word queries. If your code can indeed only handle 2-word queries and not an arbitrary number of query words, that is also fine for this exercise, you won't get less points because of that. Your second question is also very valid. You should put the various functionalities into modules / classes of their own, so that you can easily combine them for the three different binaries required for Exercises 1 - 3. Each of your three programs will then be quite short, just putting together the right things. I should have added it to my list of evil coding NoNos: never ever duplicate code, but instead put it in a class / module of its own. I hope this answers your questions, if not please ask again. Sorry for the late answer, but I was super busy until now, hardly had time to breathe. '''Hannah 30Oct09 19:08''' | When you scan, please make sure that you do something very simple with the elements, like summing up all doc ids, and then outputting that sum. Otherwise a clever compiler might figure out that it can remove the whole loop, because it is not producing a result that is used anywhere. '''Hannah 28Nov09 11:48pm''' |
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To Mirko: Yes, scanning means one pass over the elements. '''Marjan 28Nov09 19:19''' | |
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I have a question concerning exercise 2. There was no concrete task to produce "query processing code" on ex sheet 1. Are there any requirements that have to be fulfilled? Should it be able to handle two word queries? n-word queries? Additionally there is something else I want to ask: I think it surely isn't bad practice to write a more generic webserver and use it for exercises 1-3. Apart from that it says "change your code" some times in the exercises. How should your submission behave w.r.t. the exercises? Different src files / executables for each exercise? One program that solve each exercises depending on startup parameters? Anything else? '''Björn 30ct09 2:25pm''' I now reorganized the page. Old stuff went to separate pages (links above). The idea is that the front page is always for the current lecture / exercises. The problem with your exercise page should be solved now, Ivo. '''Hannah 30ct09 00:05am''' Having problems to access my exercise page after loging in - IvoChichkovExercises, '''Ivo 29Oct 22:56pm''' Sorry to bother you. I added the Link to exercise sheet 2 with the linked pdf. Needed this to find the sheet as fast as possible. '''Marius 29Oct 10:04 p.m.''' Is there a webpage for exercise sheet 2 somewhere? '''Johannes 29Oct 07:45 pm''' |
Hi, about exercise2: is by "scanning" meant that one looks at every element exactly once? (=> costs of scanning a list are just the size of the list) '''Mirko 28Nov, 19:12''' |
Welcome to the Wiki page of the course Search Engines, WS 2009 / 2010. Lecturer: Hannah Bast. Tutorials: Marjan Celikik. Course web page: click here.
Here are PDFs of the slides of the lectures so far: Lecture 1, Lecture 2, Lecture 3, Lecture 4, Lecture 5, Lecture 6.
Here are .lpd files of the recordings of the lectures so far (except Lecture 2, where we had problems with the microphone): Recording Lecture 1, Recording Lecture 3, Recording Lecture 4, Recording Lecture 5 (no audio), Recording Lecture 6 (with audio for a change).
Here are PDFs of the exercise sheets so far: Exercise Sheet 1, Exercise Sheet 2, Exercise Sheet 3, Exercise Sheet 4, Exercise Sheet 5, Exercise Sheet 6.
Here are your solutions and comments on the previous exercise sheets: Solutions and Comments 1, Solutions and Comments 2, Solutions and Comments 3, Solutions and Comments 4, Solutions and Comments 5.
Exercise Sheet 6
The recordings of all lectures are now available, see above. Lecture 2 is missing because we had technical problems there. To play the recordings (it's .lpd files) you need the Lecturnity Player. You can download the player for free here.
Here are the rules for the exercises as explained in Lecture 2.
Here you can upload your solutions for Exercise Sheet 6.
Questions or comments below this line, most recent on top please
Notice about Problem 2: You should use precise timers when measuring the running times. If your collection is very small and you round up your times, it's easy to get 0 ms when merging or scanning the inverted lists. I recommend using microsecond scale. Marjan 29Nov09 16:47
To Florian: Yes, you can do anything you want to find those words (as long as you produce the required outputs). Marjan 29Nov09 16:44
For exercise 1, should we use one of the methods presented in the lecture to find all words in the collection with the prefixes or can we do just anything to get them (though it might not be as efficient)? Florian 29Nov09 03:51pm
When you scan, please make sure that you do something very simple with the elements, like summing up all doc ids, and then outputting that sum. Otherwise a clever compiler might figure out that it can remove the whole loop, because it is not producing a result that is used anywhere. Hannah 28Nov09 11:48pm
To Mirko: Yes, scanning means one pass over the elements. Marjan 28Nov09 19:19
Hi, about exercise2: is by "scanning" meant that one looks at every element exactly once? (=> costs of scanning a list are just the size of the list) Mirko 28Nov, 19:12