Pastebin launched a little side project called VERYVIRAL.com, check it out ;-) Want more features on Pastebin? Sign Up, it's FREE!
Guest

DB class 2013 (class2go): Office Hours #1 by TA Garrett

By: a guest on Feb 5th, 2013  |  syntax: None  |  size: 67.40 KB  |  views: 75  |  expires: Never
download  |  raw  |  embed  |  report abuse  |  print
Text below is selected. Please press Ctrl+C to copy to your clipboard. (⌘+C on Mac)
  1. [23:29:51] <Imagineer1212> still learning how this works
  2. [23:29:56] --> RichGski (424c4e52@gateway/web/freenode/ip.66.76.78.82) has joined #stanford-databases
  3. [23:30:02] <mdmcginnis> Chimes are ringing 4:30 here in Texas.
  4. [23:30:06] --> LightKnight (~gabry@adsl-ull-205-217.40-151.net24.it) has joined #stanford-databases
  5. [23:30:15] <YoungDruid> btw. what base language are you taught in universities?
  6. [23:30:19] <LightKnight> Good evening
  7. [23:30:22] --> garrett_schlesin (~Adium@171.66.46.183) has joined #stanford-databases
  8. [23:30:33] <Imagineer1212> has anyone started on the interactive questions ??
  9. [23:30:35] <BethMonk> The think with punch cards is not to drop the stack before you put them into the reader. Otherwise it can take a long time to get things in order again!
  10. [23:30:36] <YoungDruid> we are taught Pascal or c++
  11. [23:30:37] --> alex___ (ae5e0e1b@gateway/web/freenode/ip.174.94.14.27) has joined #stanford-databases
  12. [23:30:43] --> exicer (~exicer@host86-169-43-251.range86-169.btcentralplus.com) has joined #stanford-databases
  13. [23:30:45] <CasperBHansen> At University of Copenhagen we start with SML and move on to Java
  14. [23:30:50] <garrett_schlesin> Hello all, I'm available to answer questions now
  15. [23:30:55] <Bruce> Is anyone having issues with installing the JSON plugin for Eclipse.  I can not seem to get in installed
  16. [23:31:03] <CasperBHansen> From then on out we are pretty much free to choose any language
  17. [23:31:14] <JennyOest> Hi Garrett - Thanks for doing this!
  18. [23:31:20] --> Sanja (5d8d0813@gateway/web/freenode/ip.93.141.8.19) has joined #stanford-databases
  19. [23:31:28] <LightKnight> yeah, thanks garrett_schlesin for your service :-)
  20. [23:31:29] <drostie> Imagineer1212: what do yoou mean the "interactive questions" exactly?
  21. [23:31:34] --> anon (~anon@unaffiliated/anon) has joined #stanford-databases
  22. [23:31:48] <LightKnight> interactive questions: http://class2go.stanford.edu/db/Winter2013/interactive_exercises
  23. [23:31:50] --> denys (c22ca046@gateway/web/freenode/ip.194.44.160.70) has joined #stanford-databases
  24. [23:31:53] <Bruce> to BethMonk  I did not think anyone used punch cards anymore
  25. [23:31:55] --> annaP (5d23d556@gateway/web/freenode/ip.93.35.213.86) has joined #stanford-databases
  26. [23:31:57] <Guest5607> Garrett, I have a quick qwuestion about the abstract quiz question from Re. Algebra.  Meaning, when they ask to consider R(A,B) with r unique tuples and S(B,C) with s unique tuples, I haven't any idea how to calculate it.  Can anyone provide insight?
  27. [23:32:09] <RussiaM> Hello Garrett, I just signed up for the class today.  Wondering how to get caught up? Should I skip the first assignment?
  28. [23:32:15] --> sefk (~Adium@171.66.40.181) has joined #stanford-databases
  29. [23:32:27] <Imagineer1212> the interactive exercise
  30. [23:32:40] <drostie> Guest5607: aren't they just asking for the size of a Cartesian product?
  31. [23:32:50] <LightKnight> RussiaM: if you take a suggestion, you should do them, for training if nothing else
  32. [23:33:16] --> narain (saxenahn@106.210.4.67) has joined #stanford-databases
  33. [23:33:23] <-- jose___ (be83d36a@gateway/web/freenode/ip.190.131.211.106) has quit (Quit: Page closed)
  34. [23:33:30] --> againme (9390ce56@gateway/web/freenode/ip.147.144.206.86) has joined #stanford-databases
  35. [23:33:33] <Bruce> Have any of the instructors logged in yet?
  36. [23:33:36] <Imagineer1212> go that part, need to know how to run validations for parsers
  37. [23:33:41] --> Newman5 (ae6ec39e@gateway/web/freenode/ip.174.110.195.158) has joined #stanford-databases
  38. [23:33:49] --> Bruno1979 (4d36cdbc@gateway/web/freenode/ip.77.54.205.188) has joined #stanford-databases
  39. [23:33:52] <LightKnight> garrett_schlesin is here, Bruce
  40. [23:33:53] <garrett_schlesin> Guest5607: which question number are you referring to?
  41. [23:34:03] <Imagineer1212> #1
  42. [23:34:07] --> AndyKay (~andykay@unaffiliated/andykay) has joined #stanford-databases
  43. [23:34:16] <LightKnight> I haven't touched Rel. Alg. yet, need to hurry up :)
  44. [23:34:23] --> metalmax1103 (c713f879@gateway/web/freenode/ip.199.19.248.121) has joined #stanford-databases
  45. [23:34:34] <JennyOest> Is there a specific topic for today's discussion?
  46. [23:34:38] <Imagineer1212> getting error message that states parser error
  47. [23:34:52] --> Matt___ (4cb4266e@gateway/web/freenode/ip.76.180.38.110) has joined #stanford-databases
  48. [23:35:02] <garrett_schlesin> RussiaM, you haven't missed too much, so I would recommend starting from the beginning
  49. [23:35:06] --> Saso_ (59d4e85a@gateway/web/freenode/ip.89.212.232.90) has joined #stanford-databases
  50. [23:35:13] <-- anony (0fc3c95a@gateway/web/freenode/ip.15.195.201.90) has quit (Quit: Page closed)
  51. [23:35:15] <Guest5607> Q3 from Re: Algebra Quiz.  Just too abstract.  I had to take that quiz to further flesh out how to calculate join and natural join, which I've figured out, but the abstraction isn't making sense.
  52. [23:35:27] --> tevy (be2a07f7@gateway/web/freenode/ip.190.42.7.247) has joined #stanford-databases
  53. [23:35:32] <garrett_schlesin> today, we're focusing on the work due next monday 01/28
  54. [23:35:37] <denys> Question about challenge-level exercises. Is it expected searching some new information to solve these exercise? Can I solve them using only information given in video lectures?
  55. [23:35:39] --> Pendurti (6025d3cb@gateway/web/freenode/ip.96.37.211.203) has joined #stanford-databases
  56. [23:35:39] <garrett_schlesin> if we have time, I can answer other questions
  57. [23:35:44] <JennyOest> thanks Garrett
  58. [23:35:46] <-- sefk1 (~sefk@171.66.35.246) has quit (Quit: Leaving.)
  59. [23:35:56] <Imagineer1212> OK thanks
  60. [23:36:04] <-- jbau (~jbau@171.66.45.147) has quit (Remote host closed the connection)
  61. [23:36:11] <CasperBHansen> I have a question; we were doing object-oriented programming and design exam last week, and following that the next day we had linear algebra exam. I didn't make the quiz before the due date, can I still complete the course with credentials and all that?
  62. [23:36:17] <-- RussiaM (84efb54d@gateway/web/freenode/ip.132.239.181.77) has quit (Ping timeout: 245 seconds)
  63. [23:36:22] <Bruce> Garrett could you post something about the Eclipse editor used in the video,  I can not seem to get the sourceforge plugin installed in any version of eclipse.  It would be nice to know information
  64. [23:36:30] <-- annaP (5d23d556@gateway/web/freenode/ip.93.35.213.86) has quit (Client Quit)
  65. [23:36:42] --> dnslnsyjhnsn (~Adium@67.137.39.240) has joined #stanford-databases
  66. [23:36:52] <-- Kendra (~kendra@pool-70-109-154-97.cncdnh.east.myfairpoint.net) has quit (Quit: Colloquy for iPad - http://colloquy.mobi)
  67. [23:36:59] <AP_> Garrett - i was self learning your course on coursera. My question is if there are a large number of joins in a query, say 4-5 joins, is there a specific order in which the db processes them, say left to right or vice versa?
  68. [23:37:11] <Bruce> I want to work on the JSON problems but need to get an editor to work first
  69. [23:37:24] <garrett_schlesin> Guest5607: we're asking you to compute the number of possible tuples when you join R and S
  70. [23:37:32] <-- sefk (~Adium@171.66.40.181) has quit (Quit: Leaving.)
  71. [23:37:35] --> danielkessler (~danielkes@c-24-22-210-222.hsd1.wa.comcast.net) has joined #stanford-databases
  72. [23:37:41] --> RussiaM (~dataengin@act181-77.ucsd.edu) has joined #stanford-databases
  73. [23:37:49] <drostie> Guest5607: ah. well let's take (5, 10, 500) first. Do you see why that's impossible?
  74. [23:38:05] --> JLMilla (547e667d@gateway/web/freenode/ip.84.126.102.125) has joined #stanford-databases
  75. [23:38:09] <ridebiscuit> json plugin in Chrome works great and is easy to install
  76. [23:38:12] --> sonlevu (1f855d20@gateway/web/freenode/ip.31.133.93.32) has joined #stanford-databases
  77. [23:38:39] <LightKnight> nice to hear, ridebiscuit
  78. [23:38:41] --> deirdre (4b3bee3e@gateway/web/freenode/ip.75.59.238.62) has joined #stanford-databases
  79. [23:38:48] <CasperBHansen> anyone here that can answer questions about the course?
  80. [23:38:49] <-- againme (9390ce56@gateway/web/freenode/ip.147.144.206.86) has quit (Quit: Page closed)
  81. [23:38:51] <Bruce> Where do you find the JSON plugin for Chrome?
  82. [23:38:59] <garrett_schlesin> so, say you have one tuple in R [(1, 1)] and two tuples in S [(1, 1) and (1,2)]
  83. [23:39:16] <drostie> CasperBHansen: garrett is the TA.
  84. [23:39:18] <garrett_schlesin> then there will be two tuples in the join
  85. [23:39:21] --> Smith_ (~Smith@46.161.124.67) has joined #stanford-databases
  86. [23:39:24] <ridebiscuit> https://chrome.google.com/webstore/search/json%20editor?utm_source=chrome-ntp-icon
  87. [23:39:27] <CasperBHansen> Alright :)
  88. [23:39:31] <garrett_schlesin> [(1,1,1) and (1,1,2)]
  89. [23:39:43] <Guest5607> okay, Now that is just for a join.
  90. [23:39:53] <BethMonk> Thanks, ridebiscuit.
  91. [23:39:57] --> MIW (4179356c@gateway/web/freenode/ip.65.121.53.108) has joined #stanford-databases
  92. [23:40:08] --> satori_ (~Adium@adsl-99-146-17-220.dsl.lsan03.sbcglobal.net) has joined #stanford-databases
  93. [23:40:10] <garrett_schlesin> right, which is what we're asking about
  94. [23:40:11] <Bruce> thanks for the link I will try it
  95. [23:40:43] <Guest5607> How do you find an answer like 5, 0, 100 for variables with no value?
  96. [23:40:52] <garrett_schlesin> now, if there are 5 tuples in R and 10 tuples in S, what is the biggest number of tuples that can be in the join?
  97. [23:40:52] <-- Sammitch_ (ae6c6ae2@gateway/web/freenode/ip.174.108.106.226) has quit (Ping timeout: 245 seconds)
  98. [23:41:09] --> tanya (9390ce56@gateway/web/freenode/ip.147.144.206.86) has joined #stanford-databases
  99. [23:41:19] <ridebiscuit> do you multiply? I don't get it.
  100. [23:41:38] --> catsf (~Adium@38.104.224.62) has joined #stanford-databases
  101. [23:41:39] <Guest5607> 15
  102. [23:41:40] <JennyOest> 50 max
  103. [23:41:44] <garrett_schlesin> you get a tuple every time R.B = S.B
  104. [23:41:59] --> JimJ9 (4179356c@gateway/web/freenode/ip.65.121.53.108) has joined #stanford-databases
  105. [23:42:02] <Imagineer1212> multipy the two variables
  106. [23:42:04] <Bruce> for 1/28 we need to complete the DTD interactive exercise, the JSON Quiz, and the Relational Algebra Quiz?
  107. [23:42:06] <-- quilombolo (~Smith@46.161.81.230) has quit (Ping timeout: 245 seconds)
  108. [23:42:06] <-- mokocha (~moko@adsl-dyn91.78-99-200.t-com.sk) has quit (Ping timeout: 245 seconds)
  109. [23:42:24] <-- Newman5 (ae6ec39e@gateway/web/freenode/ip.174.110.195.158) has quit (Quit: Page closed)
  110. [23:42:28] --> Smith__ (~Smith@46.161.83.74) has joined #stanford-databases
  111. [23:42:32] --> sefk (~Adium@171.66.40.181) has joined #stanford-databases
  112. [23:42:51] --> jbau (~jbau@171.66.45.147) has joined #stanford-databases
  113. [23:43:02] <Matt___> Yes... the due dates are listed next to the assignments.
  114. [23:43:02] <-- sefk (~Adium@171.66.40.181) has quit (Client Quit)
  115. [23:43:12] <-- tanya (9390ce56@gateway/web/freenode/ip.147.144.206.86) has left #stanford-databases
  116. [23:43:13] <garrett_schlesin> so, if all of the R.B values are the same and all of the S.B values are the same, you end up with 5x10 tuples in the result
  117. [23:43:29] <garrett_schlesin> and that's the biggest the result can get
  118. [23:43:31] <-- Pendurti (6025d3cb@gateway/web/freenode/ip.96.37.211.203) has quit (Quit: Page closed)
  119. [23:43:37] <drostie> Guest5607: a natural join is not concatenation, it's not 10 + 5 that you get.
  120. [23:43:51] <Imagineer1212> great
  121. [23:43:59] --> db2k (~chatzilla@p5B23753B.dip.t-dialin.net) has joined #stanford-databases
  122. [23:44:34] <db2k> hi folks. someone here who could help me? :)
  123. [23:44:42] <garrett_schlesin> hope that helps
  124. [23:44:55] <drostie> Guest5607: so just work out examples like {(1), (2)} x {(3), (4)} when the two columns have different names.
  125. [23:45:06] <Guest5607> okay, so that answers two of the questions that I had.  In natural join and join you work your way through every permutation of say R(A,B) with 5 tuples compared against S(A,B) with 10 tuples looking for identical attributes, theoretically getting 50.
  126. [23:45:27] <garrett_schlesin> right
  127. [23:45:29] <drostie> right, they could theoretically have 50 or fewer, but no more.
  128. [23:45:39] <-- Smith_ (~Smith@46.161.124.67) has quit (Ping timeout: 252 seconds)
  129. [23:45:48] <garrett_schlesin> the natural join cannot have more tuples than the cartesian product
  130. [23:45:54] <-- JimJ9 (4179356c@gateway/web/freenode/ip.65.121.53.108) has left #stanford-databases
  131. [23:46:00] <garrett_schlesin> since natural join is just a filtered cartesian product
  132. [23:46:07] <Guest5607> so, what do you do every time you add a relation, you have to multiply every potential instance for the max?  The question had three relations?
  133. [23:46:15] <-- Bruce (6b083f5b@gateway/web/freenode/ip.107.8.63.91) has quit (Quit: Page closed)
  134. [23:46:26] --> stan_db (a5f8f788@gateway/web/freenode/ip.165.248.247.136) has joined #stanford-databases
  135. [23:46:34] <garrett_schlesin> db2k: sure, I'm here to help
  136. [23:46:39] <-- MIW (4179356c@gateway/web/freenode/ip.65.121.53.108) has quit (Quit: Page closed)
  137. [23:46:39] <-- alex___ (ae5e0e1b@gateway/web/freenode/ip.174.94.14.27) has quit (Quit: Page closed)
  138. [23:46:43] --> daiyua (62fd7ed6@gateway/web/freenode/ip.98.253.126.214) has joined #stanford-databases
  139. [23:46:45] --> mjbright (0fc3b94c@gateway/web/freenode/ip.15.195.185.76) has joined #stanford-databases
  140. [23:46:50] <db2k> i've got a question regarding this exercise: "Remove all ratings where the movie's year is before 1970 or after 2000, and the rating is fewer than 4 stars. "
  141. [23:46:50] <garrett_schlesin> yes, that's correct
  142. [23:46:55] <Imagineer1212> I like the guest 5607 did this
  143. [23:47:07] <Guest5607> Obviously we are learning the algebraic functions as the foundation for the remainder of the course, not to keep on this way.  Does it get easier from an algebraic standpoint?
  144. [23:47:35] --> Sparky22 (~Sparky@vpn-noc-pool-230-29.ucsc.edu) has joined #stanford-databases
  145. [23:47:37] <garrett_schlesin> yes, Relational Algebra is the theoretical underpinning of SQL
  146. [23:47:49] <garrett_schlesin> so it's useful to understand for learning SQL
  147. [23:48:14] <Guest5607> Imagineer1212, did you find it a bit confusing as well?  I am no mathmetician and am struggling a bit, but am enjoying myself immensely.  Just a tad difficult.
  148. [23:48:25] <denys> <garrett_schlesin>Question about challenge-level exercises. Is it expected searching some new information to solve these exercise? Can I solve them using only information given in video lectures?
  149. [23:48:28] <garrett_schlesin> but you should find SQL less theoretical and very applicable
  150. [23:48:31] --> Christine_presen (638ca94d@gateway/web/freenode/ip.99.140.169.77) has joined #stanford-databases
  151. [23:48:59] <garrett_schlesin> denys: yes, you can solve challenge level exercises based on the content of the videos
  152. [23:49:12] <garrett_schlesin> they involve a little more critical thinking
  153. [23:49:14] --> Jaak1946 (c29641a7@gateway/web/freenode/ip.194.150.65.167) has joined #stanford-databases
  154. [23:49:36] <garrett_schlesin> db2k: what is your question?
  155. [23:49:53] <db2k> suppose i got the candidates that need to be removed with
  156. [23:49:54] <db2k> select rID, mID, stars, ratingDate from Movie join Rating using(mID)
  157. [23:49:56] <db2k> where (year < 1970 or year > 2000) and stars < 4)
  158. [23:49:56] <MikeDub> when will the next office hours be?
  159. [23:50:00] <Imagineer1212> I understand the math portion, writing programs is new to me
  160. [23:50:10] --> giovisah (~giovisah@187.144.63.226) has joined #stanford-databases
  161. [23:50:13] <-- Denise_ (8dd943c9@gateway/web/freenode/ip.141.217.67.201) has quit (Quit: Page closed)
  162. [23:50:18] --> ife (62c0defe@gateway/web/freenode/ip.98.192.222.254) has joined #stanford-databases
  163. [23:50:32] <garrett_schlesin> MikeDub: I'm planning to use this time slot every week for office hours
  164. [23:50:47] <db2k> i just do not understand how to delete these lines
  165. [23:50:49] <Imagineer1212> awesome
  166. [23:50:54] <stan_db> Q: Can I just "audit" the class and not turn in any quizzes or homework?  I am learning a lot just by listening to the videos.
  167. [23:50:56] <MikeDub> k thx
  168. [23:51:02] <drostie> denys: did you have questions about particular challenge exercises? I could help with those maybe.
  169. [23:51:17] <-- irishgringo (~chatzilla@c-71-229-99-200.hsd1.fl.comcast.net) has quit (Ping timeout: 244 seconds)
  170. [23:51:20] <LightKnight> garrett_schlesin: cool. It would even suite my timezone, but I can't speak for others :)
  171. [23:51:25] <LightKnight> *suit
  172. [23:51:31] --> Ramza (~Ramza@76.14.7.194) has joined #stanford-databases
  173. [23:51:43] --> JuneJune (ae5c3a42@gateway/web/freenode/ip.174.92.58.66) has joined #stanford-databases
  174. [23:51:49] --> BruceGumbert (6b083f5b@gateway/web/freenode/ip.107.8.63.91) has joined #stanford-databases
  175. [23:51:53] <garrett_schlesin> stan_db: yes, you can "audit"
  176. [23:51:53] <-- newxplanet (455bdcb5@gateway/web/freenode/ip.69.91.220.181) has quit (Quit: Page closed)
  177. [23:51:59] <Guest5607> is there somewhere we can view this transcript, post-discussion, in case some questions are answered.  I have to duck out.  5:00  CST.
  178. [23:52:00] <drostie> db2k: the obvious thing would be to invert that condition -- where NOT (stuff).
  179. [23:52:07] <garrett_schlesin> there is no penalty for not completing the course
  180. [23:52:27] <drostie> except that you don't complete it. ^_^
  181. [23:52:30] <JennyOest> Is there a way to turn off all the extraneous messages - the ins and outs?
  182. [23:52:32] <-- JLMilla (547e667d@gateway/web/freenode/ip.84.126.102.125) has quit (Ping timeout: 245 seconds)
  183. [23:52:36] <garrett_schlesin> db2k: have you watched the SQL videos on delete?
  184. [23:52:46] <db2k> yes i have. but i can only access the lines that needed to be deleted via a key. and the rating
  185. [23:52:50] <Imagineer1212> yes drostie, I am working the interactive exercise right now . I did the first question and it has an error message stating a parser error can you help me?
  186. [23:52:53] <drostie> JennyOest: that depends on your chat client, most have some way.
  187. [23:53:03] <garrett_schlesin> this question is a case for the "delete from where" construction, as in http://www.w3schools.com/sql/sql_delete.asp
  188. [23:53:12] <drostie> Imagineer1212: link me the page if that's possible?
  189. [23:53:19] <db2k> the primary key on the rating table would be the tuple out of the 4 attributes
  190. [23:53:33] <-- kalatad (~kaloyan@87-126-72-103.btc-net.bg) has left #stanford-databases
  191. [23:53:37] <-- JennyOest (47408203@gateway/web/freenode/ip.71.64.130.3) has quit (Quit: Page closed)
  192. [23:53:37] <drostie> Imagineer1212: I'm assuming you mean the relational algebra exercises?
  193. [23:53:44] --> moko1 (~moko@46.229.224.194.vnet.sk) has joined #stanford-databases
  194. [23:54:07] --> LinkedList (~LinkedLis@ool-4352b685.dyn.optonline.net) has joined #stanford-databases
  195. [23:54:07] --> JLMilla (547e667d@gateway/web/freenode/ip.84.126.102.125) has joined #stanford-databases
  196. [23:54:14] --> vorDd (4b45b172@gateway/web/freenode/ip.75.69.177.114) has joined #stanford-databases
  197. [23:54:26] <db2k> tried delete from rating where (rID, mID, stars, ratingDate) in (select something) but sqlite wont take it :)
  198. [23:54:39] <-- LinkedList (~LinkedLis@ool-4352b685.dyn.optonline.net) has quit (Client Quit)
  199. [23:54:57] --> Deb (cc0eefd0@gateway/web/freenode/ip.204.14.239.208) has joined #stanford-databases
  200. [23:55:04] <vorDd> did office hours start?
  201. [23:55:08] --> nonamelive (~nonameliv@123.114.41.30) has joined #stanford-databases
  202. [23:55:09] <-- Guest79793 (9390ce56@gateway/web/freenode/ip.147.144.206.86) has quit (Quit: Page closed)
  203. [23:55:16] <Imagineer1212> this is what it says??Error messages from xmllint: /tmp/tmpSG7uSi.dtd:1: parser error : ContentDecl : ',' '|' or ')' expected
  204. [23:55:20] <drostie> db2k: you might be able to limit to ids and just say where (rID) in (select ids) ?
  205. [23:55:53] <db2k> rID is not a primary key in Rating
  206. [23:55:54] <BruceGumbert> I have found that the http://www.w3resource.com/ web site has a lot of useful tutorials on just about everything in the course if you need some other source of information
  207. [23:56:00] <db2k> it would delete too much
  208. [23:56:00] <Imagineer1212> ok, I got it this is very new
  209. [23:56:25] <YoungDruid> db2k: so do  = mId in (select ...) =
  210. [23:56:27] --> sefk (~Adium@171.66.40.181) has joined #stanford-databases
  211. [23:56:33] <denys> <drostie> sanks, but I will try to solve them myself, can I ask questions next week if I won't solve them?
  212. [23:56:34] <-- CasperBHansen (~casperbha@0x3ec73ca2.inet.dsl.telianet.dk) has quit (Remote host closed the connection)
  213. [23:56:39] <drostie> Imagineer1212: aha. Your DTD is written incorrectly. If  you paste it to http://bpaste.net/ I might be able to help you.
  214. [23:56:42] --> goldsmij (ab438c43@gateway/web/freenode/ip.171.67.140.67) has joined #stanford-databases
  215. [23:56:43] --> Lilian (3288ad66@gateway/web/freenode/ip.50.136.173.102) has joined #stanford-databases
  216. [23:56:45] <stan_db> Thanks for the info BruceGumbert
  217. [23:56:46] --> jentolearn (47ca69fb@gateway/web/freenode/ip.71.202.105.251) has joined #stanford-databases
  218. [23:57:01] --> X-Scale (email@2001:470:1f14:135b::2) has joined #stanford-databases
  219. [23:57:24] <BruceGumbert> When you are writing SQL the syntax has to be exact for the query if you misspell anything the query will not work
  220. [23:57:25] --> EricStraub (322e7b88@gateway/web/freenode/ip.50.46.123.136) has joined #stanford-databases
  221. [23:57:41] --> jaba (bc31216f@gateway/web/freenode/ip.188.49.33.111) has joined #stanford-databases
  222. [23:57:52] <drostie> Imagineer1212: I would guess that you did something like <!ELEMENT element_name> and forgot to say what its children look like, but I can't know without more info.
  223. [23:58:09] <-- Vivekananda (~Vivekanan@c-69-140-191-111.hsd1.md.comcast.net) has quit (Quit: Leaving)
  224. [23:58:09] <-- jentolearn (47ca69fb@gateway/web/freenode/ip.71.202.105.251) has quit (Client Quit)
  225. [23:58:10] --> staubsauger (d1b4f023@gateway/web/freenode/ip.209.180.240.35) has joined #stanford-databases
  226. [23:58:12] <BruceGumbert> Also there are variations in standard SQL syntax from one DB system to another  MS SQL Server is really bad with non standard syntax
  227. [23:58:14] <RichGski> Are the challenge level exercises due on the same date as the regular exercise? They don't have a date in the schedule.
  228. [23:58:43] <-- anon (~anon@unaffiliated/anon) has quit (Quit: ChatZilla 0.9.89-rdmsoft [XULRunner 1.9.0.17/2009122204])
  229. [23:58:51] <-- vorDd (4b45b172@gateway/web/freenode/ip.75.69.177.114) has quit (Client Quit)
  230. [23:59:04] <Imagineer1212> I pasted it to you. Can you so me where it is wrong
  231. [23:59:05] <-- jaba (bc31216f@gateway/web/freenode/ip.188.49.33.111) has quit (Client Quit)
  232. [23:59:06] <denys> <RichGski> they are due to the end of the course
  233. [23:59:08] --> piksu (a689bf21@gateway/web/freenode/ip.166.137.191.33) has joined #stanford-databases
  234. [23:59:08] <garrett_schlesin> db2k: you could find the correct year range instead using something like "where mID in (select ….)"
  235. [23:59:25] <-- giovisah (~giovisah@187.144.63.226) has left #stanford-databases
  236. [23:59:35] --> tent405 (~morticide@wsip-70-183-186-241.cl.ri.cox.net) has joined #stanford-databases
  237. [23:59:38] <garrett_schlesin> that will probably be a better strategy than using a join
  238. [00:00:00] - {Day changed to Fri Jan 25 00:00:00 2013}
  239. [00:00:22] <BruceGumbert> Garrett are you suggesting using a nested query ?
  240. [00:00:41] <db2k> ok. i could generate a mID set with the correct year range and a rID set with a correct rating range
  241. [00:00:42] <-- narain (saxenahn@106.210.4.67) has quit (Ping timeout: 272 seconds)
  242. [00:00:46] --> jp_cal (18cd25cd@gateway/web/freenode/ip.24.205.37.205) has joined #stanford-databases
  243. [00:01:07] <voo> garrett can you talk about theta join?
  244. [00:01:08] --> chmereles (ba7b8501@gateway/web/freenode/ip.186.123.133.1) has joined #stanford-databases
  245. [00:01:21] --> narain (~saxenahn@106.202.166.104) has joined #stanford-databases
  246. [00:01:23] <tent405> what time do these office hours end?
  247. [00:01:25] <db2k> but that wont help me in the end ^^
  248. [00:01:27] <garrett_schlesin> possibly, or just conjoin "where rating < 4 and mid in (select …)"
  249. [00:01:32] --> end__ (9390ce56@gateway/web/freenode/ip.147.144.206.86) has joined #stanford-databases
  250. [00:01:39] <garrett_schlesin> tent405: 4pm PST
  251. [00:01:50] <BruceGumbert> Also with multiple joins you can sometime generate a Cartesian in larger dataset which is very messy processing wise
  252. [00:01:52] <tent405> 2 hours from now?
  253. [00:01:57] <garrett_schlesin> voo: yes, what about theta join?
  254. [00:02:03] <garrett_schlesin> tent405: one hour
  255. [00:02:07] <-- Saso_ (59d4e85a@gateway/web/freenode/ip.89.212.232.90) has quit (Ping timeout: 245 seconds)
  256. [00:02:25] <-- Smith__ (~Smith@46.161.83.74) has quit (Quit: Leaving)
  257. [00:02:29] --> jep (473ae26a@gateway/web/freenode/ip.71.58.226.106) has joined #stanford-databases
  258. [00:02:34] <drostie> Imagineer1212: you have to give me the link.
  259. [00:02:38] <Imagineer1212> drostie did you re'd the pasted message
  260. [00:02:59] <voo> a two tuple relation to a three tuple relation -- how is the schema applied?
  261. [00:03:10] <-- mikey091 (~mikey091@cpe-69-206-238-212.nyc.res.rr.com) has quit (Quit: mikey091)
  262. [00:03:10] <YoungDruid> garrett_schlesin: why is mId in (select) bad solution?
  263. [00:03:12] <-- jep (473ae26a@gateway/web/freenode/ip.71.58.226.106) has quit (Client Quit)
  264. [00:03:20] <Imagineer1212> http://bpaste.net/show/jklnEB1t8a5UwzqEVDBq/
  265. [00:03:47] <garrett_schlesin> voo: not sure what you mean by "how is the schema applied?"
  266. [00:04:03] <drostie> Imagineer1212: paste me the DTD that you're using, is more helpful for me.
  267. [00:04:26] <-- latadeyek (~Freenode@197.242.109.250) has quit (Ping timeout: 255 seconds)
  268. [00:04:40] --> latadeyek (~Freenode@197.255.172.109) has joined #stanford-databases
  269. [00:04:46] <garrett_schlesin> YoungDruid: because "delete from where" basically goes through every tuple in the table, checks the "where" condition", and deletes if that condition is true
  270. [00:04:48] <Imagineer1212> <!ELEMENT countries (countries_name countries_population countries_area)> <! ATTLIST countries  languages_ list CDATA languages> <! ATTLIST languages_id  ID  # REQUIRED> <! ATTLIST countries  population_ name CDATA cities> <! ATTLIST population_area ID # REQUIRED>
  271. [00:05:04] <-- denys (c22ca046@gateway/web/freenode/ip.194.44.160.70) has quit (Quit: Page closed)
  272. [00:05:16] <Imagineer1212> This easy for some, but new to me !!
  273. [00:05:22] --> coolweny (8172f4c5@gateway/web/freenode/ip.129.114.244.197) has joined #stanford-databases
  274. [00:05:25] <-- Sherry (4b1b3c66@gateway/web/freenode/ip.75.27.60.102) has quit (Quit: Page closed)
  275. [00:05:25] --> BewareofDoug (~Doug__@wikipedia/Doug) has joined #stanford-databases
  276. [00:05:33] <garrett_schlesin> the problem specifies that you only delete ratings with a review < 4 stars
  277. [00:05:47] <-- coolweny (8172f4c5@gateway/web/freenode/ip.129.114.244.197) has quit (Client Quit)
  278. [00:05:47] --> AdriC_ (be0a3892@gateway/web/freenode/ip.190.10.56.146) has joined #stanford-databases
  279. [00:05:49] <sonlevu> voo: 2 tuples multiply to 3 tuples--> you get a new relation with 6 tuples
  280. [00:05:58] <db2k> AND a certain production year
  281. [00:06:23] <-- sefk (~Adium@171.66.40.181) has quit (Quit: Leaving.)
  282. [00:06:33] <LightKnight> challenge-level exercises are graded and are due by the end of the course -- did I get it right?
  283. [00:06:50] --> aeh (~aeh@76-250-90-115.lightspeed.austtx.sbcglobal.net) has joined #stanford-databases
  284. [00:07:04] <garrett_schlesin> so if your statement starts with "delete from Review where", then you already have access to the information about the rating, so you can just check right there if the rating is < 4 stars
  285. [00:07:13] --> taoquay (~taoquay@69-196-176-173.dsl.teksavvy.com) has joined #stanford-databases
  286. [00:07:20] --> sefk (~Adium@171.66.40.181) has joined #stanford-databases
  287. [00:07:20] <libertyfire> end of the course = March 23
  288. [00:07:28] <LightKnight> yes
  289. [00:07:30] <db2k> mhh
  290. [00:07:30] --> caligari (~caligari@15.197.165.83.dynamic.mundo-r.com) has joined #stanford-databases
  291. [00:07:32] <BruceGumbert> Garrett are there any other relational algebra tools or additional information you would recommend.  That is the one area of the course I could use some more background on
  292. [00:07:34] <LightKnight> or so I understod
  293. [00:07:38] <LightKnight> *understood
  294. [00:07:39] --> culturelabs (~culturela@pool-108-13-20-17.lsanca.fios.verizon.net) has joined #stanford-databases
  295. [00:07:41] <garrett_schlesin> no need to do something complicated by checking in a subquery if the rating is < 4 stars, since it's available at the top level
  296. [00:07:58] <Imagineer1212> http://bpaste.net/?reply_to=ilFkIx6eejpcEd1Iqae9
  297. [00:08:04] <drostie> Imagineer1212: okay. The first problem is just that (a b c d) does not have a meaning for child elements in DTD. separating things by whitespace has no meaning.
  298. [00:08:06] <-- stan_db (a5f8f788@gateway/web/freenode/ip.165.248.247.136) has quit (Quit: Page closed)
  299. [00:08:16] <RichGski> See http://class2go.stanford.edu/db/Winter2013/pages/grading for when challenge level exercises are due
  300. [00:08:17] <db2k> got it. THANK YOU!!! :)
  301. [00:08:18] <drostie> Imagineer1212: you probably want (a, b, c, d), the comma operator.
  302. [00:08:23] <garrett_schlesin> voo: that's the maximum
  303. [00:08:43] --> Walt (63227e16@gateway/web/freenode/ip.99.34.126.22) has joined #stanford-databases
  304. [00:08:49] --> duffy (~duffy@S01067cb21b20db3e.wp.shawcable.net) has joined #stanford-databases
  305. [00:08:50] <RussiaM> BruceGumbert: Thanks for the link, SQL JOIN Cheat Sheet is super helpful
  306. [00:08:54] <garrett_schlesin> but, it's possible to have fewer tuples in a natural join or theta join
  307. [00:09:07] <-> Walt is now known as Guest47725
  308. [00:09:25] <drostie> Imagineer1212: you will also run into other problems like <!ATTLIST ...> not <!  ATTLIST ...> but I trust that you can figure such things out?
  309. [00:09:26] <-- nonamelive (~nonameliv@123.114.41.30) has quit (Ping timeout: 252 seconds)
  310. [00:09:45] <voo> garrett_schlesin i guess i'm stuck on having something equal like in the join -- theta join doesn't really always give a tuple -- so thanks anyway
  311. [00:09:50] <garrett_schlesin> BruceGumbert: you could try the extra relational algebra problems (http://class2go.stanford.edu/db/Winter2013/pages/opt-rel-algebra)
  312. [00:10:08] <garrett_schlesin> they're not autograded, but they will provide you with extra practice
  313. [00:10:12] <Imagineer1212> OK I see now !!!
  314. [00:10:31] <garrett_schlesin> voo: I'm still not sure what you mean
  315. [00:10:41] <garrett_schlesin> theta join always takes a condition
  316. [00:10:45] --> mjstrwy (8ca04271@gateway/web/freenode/ip.140.160.66.113) has joined #stanford-databases
  317. [00:11:06] <garrett_schlesin> it's equivalent to a cross product which is then filtered by a select
  318. [00:11:22] <-- QF-MichaelK (~flux@unaffiliated/qf-michaelk) has left #stanford-databases
  319. [00:11:34] --> QF-MichaelK (~flux@unaffiliated/qf-michaelk) has joined #stanford-databases
  320. [00:12:17] <BruceGumbert> Garrett thanks for the info.  I completed a DB course over 10 years ago and just need some refresher info on RA since we did not cover it in to much details since most of the students did not have strong math background
  321. [00:12:33] <-- Guest47725 (63227e16@gateway/web/freenode/ip.99.34.126.22) has quit (Client Quit)
  322. [00:12:35] <tent405> garrett_schlesin: i'm having a problem understanding the phrasing of RA challenge #1. the crucial part that i'm not understanding is "or that cost less than $10... everywhere they're served".
  323. [00:12:36] <tent405> Well first of all a pizza can't cost something at a place where it's not served, so that just reads "or that cost less than $10".. and that includes all pizzas.. what am i missing?
  324. [00:12:36] <tent405> Could you rephrase it a different way
  325. [00:13:12] <Aloha> hi, I finished all the DTD exercises but there's 1 dumb question. What does * mean? It seems to mean both OPTIONAL and CAN HAVE MORE THAN 1 OCCURENCES to me. Is that right?
  326. [00:13:37] --> JLMilla_ (547e667d@gateway/web/freenode/ip.84.126.102.125) has joined #stanford-databases
  327. [00:13:43] <libertyfire> * means zero or more
  328. [00:13:44] <-- Bruno1979 (4d36cdbc@gateway/web/freenode/ip.77.54.205.188) has quit (Quit: Page closed)
  329. [00:13:48] <LightKnight> Aloha: "*" mean "any number of occurrences, from 0 to infinity"
  330. [00:13:59] <Imagineer1212> thank you, I need more practice with this and if I can figure out where I am going wrong then it will be easier for me to find.
  331. [00:14:04] <LightKnight> "+": 0 or more; "+": 1 or more; "?": 1 or 2
  332. [00:14:12] <garrett_schlesin> tent405: that means that the pizza costs less than $10 at every place where it's served
  333. [00:14:15] <drostie> tent405: not that costs less than $10 at one place, but that costs less than $10 at every restaurant which serves it.
  334. [00:14:30] <BethMonk> ?: 0 or 1
  335. [00:14:37] <-- JuneJune (ae5c3a42@gateway/web/freenode/ip.174.92.58.66) has quit (Ping timeout: 245 seconds)
  336. [00:14:44] <LightKnight> erm, 0 or 1, of course.
  337. [00:14:49] <garrett_schlesin> put another way, the pizza never costs more than $10
  338. [00:14:49] -*- LightKnight sleepy :)
  339. [00:14:56] <garrett_schlesin> hope that helps
  340. [00:14:56] --> Adriana (be0a3892@gateway/web/freenode/ip.190.10.56.146) has joined #stanford-databases
  341. [00:14:59] <tent405> ok thanks that makes sense now
  342. [00:15:02] <drostie> Aloha: A* is equivalent to A+?
  343. [00:15:02] <-- JLMilla (547e667d@gateway/web/freenode/ip.84.126.102.125) has quit (Ping timeout: 245 seconds)
  344. [00:15:16] <drostie> .
  345. [00:15:29] <LightKnight> if you have no "A", this satisfies A*, but not A+, so no, they're not equivalent.
  346. [00:15:34] <BruceGumbert> thanks for the feedback on the RA stuff.  Need to get back to work on the course
  347. [00:15:40] <-- BruceGumbert (6b083f5b@gateway/web/freenode/ip.107.8.63.91) has quit (Quit: Page closed)
  348. [00:15:42] <-- taoquay (~taoquay@69-196-176-173.dsl.teksavvy.com) has quit (Ping timeout: 264 seconds)
  349. [00:15:47] <garrett_schlesin> drostie: A* means 0-infinity, A+ means 1-infinity
  350. [00:15:56] <garrett_schlesin> A? means 0 or 1
  351. [00:16:10] <dubs12> i thought ? meant optional?
  352. [00:16:10] <drostie> LightKnight, garrett_schlesin, I understand that that line ended with a question mark but it was not a question; that was syntax. :P
  353. [00:16:18] --> davemckenna (~anonymous@72-53-156-201.cpe.distributel.net) has joined #stanford-databases
  354. [00:16:23] <garrett_schlesin> lol
  355. [00:16:31] --> EricStraub_ (~chatzilla@50-46-123-136.evrt.wa.frontiernet.net) has joined #stanford-databases
  356. [00:16:49] <garrett_schlesin> that's an example of a parsing error ;)
  357. [00:16:56] <-- RichGski (424c4e52@gateway/web/freenode/ip.66.76.78.82) has left #stanford-databases
  358. [00:16:58] <pattdaddy> dubs12: the 0 makes it optional
  359. [00:17:14] <LightKnight> uhm, I guess (A+)? means 0 or 1 occurrences of A+...
  360. [00:17:19] <drostie> I should have chosen the other order to ask the question to prevent parse errors.
  361. [00:17:19] --> brian_ (~quassel@72.252.195.130) has joined #stanford-databases
  362. [00:17:25] <LightKnight> :)
  363. [00:17:32] <brian_> hello everyone
  364. [00:17:40] <-- EricStraub (322e7b88@gateway/web/freenode/ip.50.46.123.136) has quit (Quit: Page closed)
  365. [00:17:53] <-> EricStraub_ is now known as EricStraub
  366. [00:18:01] --> greenmoon55 (~smuxi@123.172.141.38) has joined #stanford-databases
  367. [00:18:06] <LightKnight> hi brian_
  368. [00:18:29] <db2k>  you need to escape the plus sign then
  369. [00:18:34] <voo> garrett_schlesin awesome job, i gotta go now, but thanks for your time and energy -- kudos
  370. [00:18:43] <Aloha> thanks friends!
  371. [00:18:46] <garrett_schlesin> voo: you're welcome
  372. [00:18:47] <dubs12> probably asked before, where can i install xmllint?
  373. [00:18:48] <garrett_schlesin> good luck
  374. [00:19:18] <garrett_schlesin> dubs12: have you seen: http://class2go.stanford.edu/db/Winter2013/pages/xml-guide
  375. [00:19:18] <db2k> dubs - i'm using notepad++ with xml plugin
  376. [00:19:27] <dubs12> ok
  377. [00:19:28] --> Mastermnd (~chatzilla@37.Red-83-50-156.dynamicIP.rima-tde.net) has joined #stanford-databases
  378. [00:19:47] <Mastermnd> hi everyone
  379. [00:19:53] <LightKnight> hi Mastermnd
  380. [00:20:03] <brian_> does anyone here use linux? if so whats a good xml platform for linux
  381. [00:20:06] <Imagineer1212> garrett will you be moving fast in this course ????
  382. [00:20:08] <garrett_schlesin> dubs: FYI, for xml editing (and lots of other code editing), I've been using Sublime Text 2
  383. [00:20:10] <dubs12> might try notepad++ alright
  384. [00:20:12] <-- end__ (9390ce56@gateway/web/freenode/ip.147.144.206.86) has left #stanford-databases
  385. [00:20:18] <LightKnight> brian_: I don't know, I always used xmllint :P
  386. [00:20:25] <LightKnight> but I'm open to suggestions :-)
  387. [00:20:35] <drostie> brian_: I'm using Kate to edit, xmllint to verify.
  388. [00:20:47] --> Souj (3cf0180f@gateway/web/freenode/ip.60.240.24.15) has joined #stanford-databases
  389. [00:20:49] <dubs12> are most of you guys running win or lin?
  390. [00:20:53] <Mastermnd> it might be just be being tired (it's 12:20am here) but i think i've found a small mistake in the accepted answer for the exercises for section "SQL Social-Network Query Exercises (challenge-level)"  ... question 4
  391. [00:20:55] <brian_> lightknight thanks
  392. [00:21:00] <LightKnight> I'm on Linux (Debian)
  393. [00:21:01] <db2k> works like a charm on win based systems :)
  394. [00:21:09] <drostie> I'm running Kubuntu. ^_^
  395. [00:21:10] <brian_> ok will work with that then
  396. [00:21:17] <dubs12> i can go with either
  397. [00:21:18] --> Toest (4a4fda46@gateway/web/freenode/ip.74.79.218.70) has joined #stanford-databases
  398. [00:21:42] <Mastermnd> anybody here to confirm? :P i think it's counting friendships twice in the average when it shouldn't be
  399. [00:21:44] <-- cgonzalez (be780408@gateway/web/freenode/ip.190.120.4.8) has quit (Quit: Page closed)
  400. [00:21:46] <brian_> kubuntu here
  401. [00:21:50] --> Astorre (~asto@net-93-144-20-192.cust.dsl.teletu.it) has joined #stanford-databases
  402. [00:21:53] --> Praveena (63770f37@gateway/web/freenode/ip.99.119.15.55) has joined #stanford-databases
  403. [00:22:06] --> colstat (cc34d707@gateway/web/freenode/ip.204.52.215.7) has joined #stanford-databases
  404. [00:22:14] <garrett_schlesin> Mastermnd: not sure what you mean
  405. [00:22:14] <dubs12> think i'll switch to mint for the remainder of the course
  406. [00:22:14] <-- Praveena (63770f37@gateway/web/freenode/ip.99.119.15.55) has quit (Client Quit)
  407. [00:22:31] <-- jerifortune (~androirc@41.190.3.215) has quit (Quit: AndroIRC - Android IRC Client ( http://www.androirc.com ))
  408. [00:22:50] <Astorre> Hi students :)
  409. [00:22:55] <dubs12> hey
  410. [00:23:01] <Mastermnd> without disclosing the full answer, i think the answer should include condition "WHERE F.ID1 < F.ID2" but it doesn't
  411. [00:23:01] <brian_> also is the course assuming you have some programming background?
  412. [00:23:04] --> nadrimajstor (b2955987@gateway/web/freenode/ip.178.149.89.135) has joined #stanford-databases
  413. [00:23:06] <Mastermnd> the average should be 2.0 not 2.5
  414. [00:23:08] <-- ridebiscuit (~Adium@c-71-202-150-212.hsd1.ca.comcast.net) has quit (Quit: Leaving.)
  415. [00:23:14] <-- goldsmij (ab438c43@gateway/web/freenode/ip.171.67.140.67) has quit (Quit: Page closed)
  416. [00:23:27] --> jerifortune (~androirc@41.190.3.215) has joined #stanford-databases
  417. [00:23:30] --> tanya (9390ce56@gateway/web/freenode/ip.147.144.206.86) has joined #stanford-databases
  418. [00:23:32] <dubs12> im only at JSON DATA section in this course
  419. [00:23:36] <Toest> Hi is anyone taking questions ?
  420. [00:23:46] <Jaak1946> I have Ubuntu linux
  421. [00:24:19] <-- Pao (ba515352@gateway/web/freenode/ip.186.81.83.82) has quit (Quit: Page closed)
  422. [00:24:19] <drostie> I'll take a question if you ask it in chat. ^_^
  423. [00:24:21] <Toest> Such as what is DTD for :   <Description>Natural language processing. Cross-listed as <Courseref Number="LING180"/>.</Description>   ???
  424. [00:24:23] <dubs12> very interesting and enjoying it so far..if only i can get more time to study :(
  425. [00:24:40] <Astorre> Hi, could someone finger me a good tutorial on DTD?
  426. [00:24:41] --> juarezmax (~juarezmax@187.151.59.44) has joined #stanford-databases
  427. [00:25:03] <Mastermnd> Toest: that's the trickiest part in the whole section :) Hint: Try looking for "mixed content dtd"
  428. [00:25:10] <drostie> Toest: the child elements are (#PCDATA | Courseref)*. Zero or more text nodes mixed with Courserefs.
  429. [00:25:20] --> Kamalesh (62e96028@gateway/web/freenode/ip.98.233.96.40) has joined #stanford-databases
  430. [00:25:27] --> RichGski (424c4e52@gateway/web/freenode/ip.66.76.78.82) has joined #stanford-databases
  431. [00:25:47] <Mastermnd> drostie: when i wrote that i got a lint error saying the result was not deterministic
  432. [00:25:56] <Toest> I found the mixed content but my parser will not accept.
  433. [00:26:03] <Mastermnd> I used "ANY" :)
  434. [00:26:31] --> rdm (rdm@unaffiliated/qubix) has joined #stanford-databases
  435. [00:26:38] <nadrimajstor> What #PCDATA stands for?
  436. [00:26:38] <Toest> The problem is that Courseref is actuallyt Courseref number !
  437. [00:26:39] <garrett_schlesin> Mastermnd: I don't think there's an error
  438. [00:26:40] <dubs12> have you guys done the DTD Exercises yet?
  439. [00:26:42] <-- dmitro72 (2ea2300b@gateway/web/freenode/ip.46.162.48.11) has quit (Ping timeout: 245 seconds)
  440. [00:26:58] <-- Imagineer1212 (18070c42@gateway/web/freenode/ip.24.7.12.66) has left #stanford-databases
  441. [00:27:00] <db2k> yupp
  442. [00:27:00] <-- greenmoon55 (~smuxi@123.172.141.38) has quit (Read error: Connection reset by peer)
  443. [00:27:02] <Astorre> no
  444. [00:27:05] <drostie> Toest: "number" is not the nodeName, it is an attribute.
  445. [00:27:30] <pattdaddy> PCDATA is a term originated from SGML, short for "Parsed Character Data"...  google is your friend
  446. [00:27:34] <tent405> garrett_schlesin: when is the next office hour?
  447. [00:27:35] <Mastermnd> garrett_schlesin can i /msg you?
  448. [00:27:35] <-- narain (~saxenahn@106.202.166.104) has quit (Ping timeout: 252 seconds)
  449. [00:27:38] <Toest> Oh... I will try any.  Oh its done with an ATTLIST.  I will try it !!!!    THanks !
  450. [00:27:43] --> steve__ (b75a67ac@gateway/web/freenode/ip.183.90.103.172) has joined #stanford-databases
  451. [00:27:48] --> Praveena (63770f37@gateway/web/freenode/ip.99.119.15.55) has joined #stanford-databases
  452. [00:27:57] <garrett_schlesin> Mastermnd: I would prefer no direct messages
  453. [00:28:22] <-- Praveena (63770f37@gateway/web/freenode/ip.99.119.15.55) has quit (Client Quit)
  454. [00:28:22] <nadrimajstor> pattdaddy: It is easier to ask on IRC :)
  455. [00:28:45] <garrett_schlesin> tent405: I'm planning to hold office hours at the same time every week
  456. [00:28:54] <Mastermnd> ok the reason i was saying i thought there was a problem is that Friend contains tuples of the form (123,456) and (456,123) because they are bidirectional
  457. [00:28:55] <LightKnight> nadrimajstor: stackoverflow.com/questions/918450/difference-between-pcdata-and-cdata-in-dtd
  458. [00:29:02] <pattdaddy> i disagree
  459. [00:29:03] <LightKnight> nadrimajstor: http://stackoverflow.com/questions/918450/difference-between-pcdata-and-cdata-in-dtd
  460. [00:29:20] --> jerry__ (45cdc0bd@gateway/web/freenode/ip.69.205.192.189) has joined #stanford-databases
  461. [00:29:21] <garrett_schlesin> Mastermnd: right, but that shouldn't cause problems
  462. [00:29:32] --> taoquay (~taoquay@108.175.227.144) has joined #stanford-databases
  463. [00:29:38] <-- weaver (ad3fbd20@gateway/web/freenode/ip.173.63.189.32) has quit (Ping timeout: 245 seconds)
  464. [00:29:40] <garrett_schlesin> you're trying to find the average number of friends per student
  465. [00:29:49] --> jimzhang (4a5eff02@gateway/web/freenode/ip.74.94.255.2) has joined #stanford-databases
  466. [00:29:56] <garrett_schlesin> so you start by counting the number of friendships per student
  467. [00:30:04] <nadrimajstor> What will happen when Stacks go offline?
  468. [00:30:29] <nadrimajstor> What will happen when Stacks go offline? :D
  469. [00:30:32] --> adijon (4853fefd@gateway/web/freenode/ip.72.83.254.253) has joined #stanford-databases
  470. [00:30:33] <garrett_schlesin> since the tuples are bidirectional, that means you can do this very easily by grouping by the first ID
  471. [00:30:41] <Mastermnd> yes that's exactly what i did
  472. [00:31:08] <-- duffy (~duffy@S01067cb21b20db3e.wp.shawcable.net) has quit (Remote host closed the connection)
  473. [00:31:17] <garrett_schlesin> direct message me your query, and I'll see if I can help
  474. [00:31:28] <-- exicer (~exicer@host86-169-43-251.range86-169.btcentralplus.com) has quit (Quit: exicer)
  475. [00:31:42] <-- Guest5607 (1801939b@gateway/web/freenode/ip.24.1.147.155) has quit (Ping timeout: 245 seconds)
  476. [00:31:46] <drostie> nadrimajstor: won't be as bad as when Wikipedia falls.
  477. [00:32:18] <nadrimajstor> drostie: All of develping skills will be gone :D
  478. [00:32:30] <-- Descartes (aa3f14ba@gateway/web/freenode/ip.170.63.20.186) has left #stanford-databases
  479. [00:32:32] <-- catsf (~Adium@38.104.224.62) has quit (Quit: Leaving.)
  480. [00:33:00] --> exicer (~exicer@host86-169-43-251.range86-169.btcentralplus.com) has joined #stanford-databases
  481. [00:33:36] <libertyfire> beets. i hate 'em
  482. [00:33:58] <-- steve__ (b75a67ac@gateway/web/freenode/ip.183.90.103.172) has quit (Quit: Page closed)
  483. [00:34:04] <-- JLMilla_ (547e667d@gateway/web/freenode/ip.84.126.102.125) has quit (Quit: Page closed)
  484. [00:34:15] --> BruceGumbert (6b083f5b@gateway/web/freenode/ip.107.8.63.91) has joined #stanford-databases
  485. [00:34:16] <-- Kamalesh (62e96028@gateway/web/freenode/ip.98.233.96.40) has quit (Quit: Page closed)
  486. [00:34:19] <nadrimajstor> Where is our professor? I want to say hi and thanks :)
  487. [00:34:37] <-- nuclearsoup (~user@86-45-158-74-dynamic.b-ras2.chf.cork.eircom.net) has quit (Quit: ERC Version 5.3 (IRC client for Emacs))
  488. [00:34:57] --> steve__ (b75a67bd@gateway/web/freenode/ip.183.90.103.189) has joined #stanford-databases
  489. [00:34:58] <drostie> the TA might relay it across? :D
  490. [00:35:02] <-- chmereles (ba7b8501@gateway/web/freenode/ip.186.123.133.1) has quit (Ping timeout: 245 seconds)
  491. [00:35:08] <-- jerifortune (~androirc@41.190.3.215) has quit (Read error: Connection reset by peer)
  492. [00:35:15] --> nonamelive (~nonameliv@123.114.41.30) has joined #stanford-databases
  493. [00:35:17] <garrett_schlesin> the professor isn't logged on
  494. [00:35:25] <garrett_schlesin> just me, the TA
  495. [00:35:32] <nadrimajstor> @TAs please be kind to
  496. [00:35:33] --> Kendra (~kendra@pool-70-109-154-97.cncdnh.east.myfairpoint.net) has joined #stanford-databases
  497. [00:35:35] <-- exicer (~exicer@host86-169-43-251.range86-169.btcentralplus.com) has quit (Client Quit)
  498. [00:36:05] --> pdub79 (48e1f835@gateway/web/freenode/ip.72.225.248.53) has joined #stanford-databases
  499. [00:36:10] <-- dejancic (5d57f13e@gateway/web/freenode/ip.93.87.241.62) has quit (Quit: Page closed)
  500. [00:36:13] <drostie> is it intimidating as a TA to have a many-thousand-person course? :D
  501. [00:36:13] --> flrazo (~Adium@ip68-7-16-204.sd.sd.cox.net) has joined #stanford-databases
  502. [00:36:26] <Toest> Here is my DTD for  <Description>Natural language processing. Cross-listed as <Courseref Number="LING180"/>.</Description> :    <!ELEMENT Description (#PCDATA|CourseRef)*>
  503. [00:36:26] <nadrimajstor> ROFL
  504. [00:36:28] <garrett_schlesin> a little bit
  505. [00:36:31] <Toest> <!ATTLIST CourseRef Number CDATA #REQUIRED>
  506. [00:36:43] <Toest> This does not seem to work !
  507. [00:37:02] <BruceGumbert> garrett I wanted to use the eclipse editor so I was wondering which one is being used in the videos and if that information along with the JSON plug in be posted in the software guide section
  508. [00:37:09] <steve__> Whads a TA???
  509. [00:37:21] <BruceGumbert> Teaching Assistant
  510. [00:37:22] <Mastermnd> Toest: it's not a CDATA
  511. [00:37:26] <steve__> ic
  512. [00:37:34] <nadrimajstor> Santas little helper :d
  513. [00:37:45] <drostie> Toest: try Courseref not CourseRef? I'm not sure if XML is case-sensitive.
  514. [00:37:55] <Toest> Ooooh.
  515. [00:37:59] <steve__> christmas is already over:)
  516. [00:38:03] <nadrimajstor> Tantas Alittle helper :d
  517. [00:38:40] <garrett_schlesin> BruceGumbert: I use eclipse Indigo
  518. [00:38:45] <sonlevu> <garrett_schlesin> Could you please give an example of using SQL and/or XML,JSON on a website, and explain briefly how it works with HTML,javascript,PHP? I've worked with HTML and Javascript(some simple exercises), but have never used sql.
  519. [00:39:11] <nadrimajstor> Can using any IDE rally help in learning ?
  520. [00:39:12] <Mastermnd> how about amazon
  521. [00:39:26] <BruceGumbert> Ok thanks I will try that but and will give them a call if I can not get the JSON plugin installed.
  522. [00:39:29] <Mastermnd> sql is used to access all info about stock, etc
  523. [00:39:33] <Matt___> This is a joke. It would be more productive to field questions via e-mail throughout the week and then post responses to items that don't involve Christmas.
  524. [00:39:33] <Mastermnd> user accounts
  525. [00:39:39] <-- dangayle (~dangayle@67.137.77.34) has quit (Quit: dangayle)
  526. [00:39:58] <BruceGumbert> which ANSI SQL standard are we using for the course?
  527. [00:40:01] <Mastermnd> sonlevu: have you used PHP?
  528. [00:40:10] <-- floyd_ (~floyd@c-24-147-81-20.hsd1.ma.comcast.net) has left #stanford-databases
  529. [00:40:20] <sonlevu> no, i haven't
  530. [00:40:34] <Mastermnd> matt: christmas stuff goes to the north pole tho
  531. [00:40:38] <-- flrazo (~Adium@ip68-7-16-204.sd.sd.cox.net) has left #stanford-databases
  532. [00:40:46] <garrett_schlesin> BruceGumbert: pretty sure this is the plugin: http://sourceforge.net/projects/eclipsejsonedit/
  533. [00:41:01] <Toest> Um, mastermind can you give me a hint here ?
  534. [00:41:08] <nadrimajstor> I'm leaving at North Pole... According to the Google Maps :D
  535. [00:41:11] <LightKnight> something lighter than Eclipse to work with JSON? :-)
  536. [00:41:15] <tent405> vi
  537. [00:41:18] <-- AdriC_ (be0a3892@gateway/web/freenode/ip.190.10.56.146) has quit (Ping timeout: 245 seconds)
  538. [00:41:18] <-- Matt___ (4cb4266e@gateway/web/freenode/ip.76.180.38.110) has quit (Quit: Page closed)
  539. [00:41:18] --> tsui (~floydtsui@c-24-147-81-20.hsd1.ma.comcast.net) has joined #stanford-databases
  540. [00:41:21] <LightKnight> ha :)
  541. [00:41:28] --> rojathepoor (~nowaysusy@gateway/tor-sasl/rojathepoor) has joined #stanford-databases
  542. [00:41:36] <BruceGumbert> I tried NotePad++ plugin but does not work well
  543. [00:41:37] <Toest> An entity ?
  544. [00:41:49] <Mastermnd> Toest: try to use IDREF instead of CDATA for that attribute... even the name suggests it's a reference ;)
  545. [00:42:08] <Mastermnd> bruce: the notepad++ plugin is what i used... works like a charm
  546. [00:42:13] <BruceGumbert> Garrett thanks for the plugin url I was finding a different one on sourceforge that would not install properly
  547. [00:42:14] <Mastermnd> xml tools plugin right?
  548. [00:42:24] <-- Guest70623 (47eb2f48@gateway/web/freenode/ip.71.235.47.72) has quit (Quit: Page closed)
  549. [00:42:35] --> Leslie_ (6c059d06@gateway/web/freenode/ip.108.5.157.6) has joined #stanford-databases
  550. [00:42:37] <sonlevu> we sent user name and password through html form to the server and the server access its database using sql?
  551. [00:42:48] <BruceGumbert> Mastermnd the Notepad++ xml tools plug in works great
  552. [00:42:51] <Mastermnd> Toest: just change CDATA for IDREF
  553. [00:42:54] <AndyKay> LightKnight: an hour ago, somebody suggested using a Chrome application to edit JSON. To me it looks quite good so far
  554. [00:43:10] <-- RichGski (424c4e52@gateway/web/freenode/ip.66.76.78.82) has quit (Quit: Page closed)
  555. [00:43:11] <LightKnight> AndyKay: saw that, thanks. I think I'll try it :)
  556. [00:43:16] <BruceGumbert> Have not tried that yet but I will
  557. [00:43:29] <BethMonk> Yes, I'm planning to try it too.
  558. [00:43:46] <BewareofDoug> drostie: yes, xml is case sensitive
  559. [00:43:47] --> Benedict_ (293a4076@gateway/web/freenode/ip.41.58.64.118) has joined #stanford-databases
  560. [00:43:50] <-- stan2go13 (6c24313f@gateway/web/freenode/ip.108.36.49.63) has left #stanford-databases
  561. [00:43:50] <-- QF-MichaelK (~flux@unaffiliated/qf-michaelk) has left #stanford-databases
  562. [00:44:07] <garrett_schlesin> sonlevu: you can embed SQL queries into PHP for dynamic webpages
  563. [00:44:42] <nadrimajstor> XML should be case sensitive... I'm not sure how M$ stands on this :D
  564. [00:44:56] <garrett_schlesin> typically, the PHP on a page will hold onto a handle to a database and display information based on who you are and what you click
  565. [00:44:57] <Toest> Ok I tried this but get err:  CourseRef unexpected to content model.  Do i have to declare Number as an ID ?
  566. [00:44:58] <pdub79> Hi, Garrett.  Sorry for joining late.  (1) Are there any rules for this IRC chat?  Or do we just ask you anything about the class / assignments?  (2) Can we find the textbook material online anywhere?
  567. [00:45:08] --> lolo (cbe2dc7e@gateway/web/freenode/ip.203.226.220.126) has joined #stanford-databases
  568. [00:45:09] --> Vivekananda (~Vivekanan@c-69-140-191-111.hsd1.md.comcast.net) has joined #stanford-databases
  569. [00:45:26] <Benedict_> hi guys
  570. [00:45:28] <AndyKay> By the way, what text editor does Prof. Widom use in the videos? Seems to be emacs (???)
  571. [00:45:30] <Vivekananda> hello everyone
  572. [00:45:32] <-> lolo is now known as Guest64226
  573. [00:45:41] <-- Kendra (~kendra@pool-70-109-154-97.cncdnh.east.myfairpoint.net) has quit (Quit: Colloquy for iPad - http://colloquy.mobi)
  574. [00:45:42] <Vivekananda> did  the TA session end ?
  575. [00:45:43] --> cpw (~cpw@netblock-66-245-218-40.dslextreme.com) has joined #stanford-databases
  576. [00:45:45] <BewareofDoug> AndyKay: which videos?
  577. [00:46:01] <BewareofDoug> She uses different ones in different videos
  578. [00:46:03] <garrett_schlesin> Vivekananda: I'm still here
  579. [00:46:04] <Benedict_> how did the class go today
  580. [00:46:05] <AndyKay> BewareofDoug: XML Data
  581. [00:46:19] <Vivekananda> garrett_schlesin: I just had one or two general questions
  582. [00:46:22] <-- vcolombo (~vcolombo@cip-248.trustwave.com) has quit (Remote host closed the connection)
  583. [00:46:31] <AndyKay> I haven't reached other ones yet, planning to do so on the weekend ...
  584. [00:46:34] <-- rstos (~rastos@dial-95-105-199-30-orange.orange.sk) has quit (Quit: Leaving.)
  585. [00:46:39] <Mastermnd> Toest: First correct the caps problem. Then be aware the Courseref is pointing to a course. so the Course number is an ID and Courseref is an IDREF
  586. [00:46:42] <LightKnight> In the XML videos it's Emacs, yes :-)
  587. [00:46:49] <garrett_schlesin> pdub79: there are recommended textbook readings on the course website
  588. [00:46:54] --> Annie (d0b91272@gateway/web/freenode/ip.208.185.18.114) has joined #stanford-databases
  589. [00:46:57] <Vivekananda> I did the challenge levels on my own but for one , getting the max value in a column I basically found hints online
  590. [00:46:58] <AndyKay> Oh... Emacs in Windows
  591. [00:47:09] <LightKnight> yes, it seems to be
  592. [00:47:13] <jimzhang> Just to see if my  typing works
  593. [00:47:15] <garrett_schlesin> and no, there aren't strictly rules for the IRC chat - just ask questions about upcoming assignments
  594. [00:47:18] <-> Annie is now known as Guest41116
  595. [00:47:30] --> flosakura (flosakura@CPE0016d4c4031f-CM0011aea52446.cpe.net.cable.rogers.com) has joined #stanford-databases
  596. [00:47:33] <-- tanya (9390ce56@gateway/web/freenode/ip.147.144.206.86) has quit (Ping timeout: 245 seconds)
  597. [00:47:39] <Toest> Oh..  This must be the case as the XML is written then ?  I didn't pick up on that.  THanks will try.
  598. [00:47:50] <Vivekananda> I want to ask you to gimme some reading material or hints for a little advanced problem solving like that. The books are not that intensive for either giving such problems of getting ways to solve it
  599. [00:47:56] <Guest41116> Hi, Garrett and all - how do you open the JSON file in a browser so that you have the option to expand as Jennifer did in the video?
  600. [00:47:57] <-- jerry__ (45cdc0bd@gateway/web/freenode/ip.69.205.192.189) has quit (Ping timeout: 245 seconds)
  601. [00:48:24] <Vivekananda> I need some foothold to be able to think coz if I know select and join only then coming up with max value for a column would be pretty tough
  602. [00:48:28] <-- Guest64226 (cbe2dc7e@gateway/web/freenode/ip.203.226.220.126) has quit (Client Quit)
  603. [00:48:31] <BewareofDoug> No, it's Xemacs
  604. [00:48:34] <BewareofDoug> not emacs
  605. [00:48:39] <BewareofDoug> The prof is using Xemacs
  606. [00:48:43] <LightKnight> ah, Xemacs
  607. [00:49:02] <BewareofDoug> emacs is a lot less gui
  608. [00:49:17] <AndyKay> Right
  609. [00:49:19] <garrett_schlesin> Vivekananda: these exercises are meant to challenge your critical thinking abilities; all of the tools you need to solve the problems are in the videos
  610. [00:49:27] <Vivekananda> garrett_schlesin: did the professor herself join in too at some point?
  611. [00:49:32] <garrett_schlesin> I can give hints, but you need to be more specific
  612. [00:49:35] -*- AndyKay is still choosing the *right* text editor
  613. [00:49:42] --> asevl (~asevl@99.36.96.46) has joined #stanford-databases
  614. [00:49:54] <-- nonamelive (~nonameliv@123.114.41.30) has quit (Ping timeout: 276 seconds)
  615. [00:49:55] <nadrimajstor> nano ?
  616. [00:49:57] <Mastermnd> notepad++ or eclipse for the win :P
  617. [00:49:57] <BewareofDoug> garrett_schlesin: not true, you have to go the specs, e.g. there's nothing in the videos re <xsd:choice>, but you can't do the quiz without that
  618. [00:50:14] <Vivekananda> garrett_schlesin: I can ask you for a hint but I would rather like to know new ways of using the basic add and substract and then think myself
  619. [00:50:20] <Vivekananda> although I finished the challanges :)
  620. [00:50:24] <steve__> All th etools you need to solve ar ein the video??
  621. [00:50:24] --> tommy1975 (5d474cef@gateway/web/freenode/ip.93.71.76.239) has joined #stanford-databases
  622. [00:50:27] <-- AP_ (75c0e377@gateway/web/freenode/ip.117.192.227.119) has quit (Ping timeout: 245 seconds)
  623. [00:50:32] <Vivekananda> but there will be more in the sql too right ?
  624. [00:50:46] <steve__> Division was never mentioned in his video lectures....
  625. [00:50:51] <nadrimajstor> notepad2 in win :'
  626. [00:51:00] <-- sonlevu (1f855d20@gateway/web/freenode/ip.31.133.93.32) has quit (Quit: Page closed)
  627. [00:51:05] <steve__> for relational algebra for challenge qn5 in RA
  628. [00:51:10] <Vivekananda> steve__: the tools of course are I think we need more critical material for critical thinking :)
  629. [00:51:31] <pdub79> Garrett - I see that textbook sections are recommended on the website.  But I'm talking about the actual text.  Do we actually have to buy the textbook?  Or am I looking in the wrong place: https://class2go.stanford.edu/db/Winter2013/pages/readings.
  630. [00:51:34] <-- Leslie_ (6c059d06@gateway/web/freenode/ip.108.5.157.6) has quit (Quit: Page closed)
  631. [00:51:38] <BewareofDoug> ah steve__ , yes, if you can use them, not everything there works on windows, not everything works on mac
  632. [00:51:39] <Benedict_> Hi vivekanada
  633. [00:51:42] <-- deirdre (4b3bee3e@gateway/web/freenode/ip.75.59.238.62) has quit (Ping timeout: 245 seconds)
  634. [00:51:44] <garrett_schlesin> Vivekananda: it's really easier if you ask specific questions
  635. [00:51:49] <Vivekananda> Benedict_: hello
  636. [00:51:52] <-- jane2 (~Adium@171.66.45.205) has quit (Quit: Leaving.)
  637. [00:52:07] <garrett_schlesin> pdub79: you don't need to buy the textbook
  638. [00:52:12] <Benedict_> did u attend the class for 9pm today
  639. [00:52:14] <Vivekananda> garrett_schlesin: ok one specific is how do I find the max value in a column in a table of integers
  640. [00:52:28] <nadrimajstor> Will I ever user Relational Algebra in real life situations?
  641. [00:52:29] <Vivekananda> second what is the meaningn of "string" < "string"
  642. [00:52:40] <Vivekananda> Benedict_: which class?
  643. [00:52:41] <garrett_schlesin> but if you want to do the readings listed on that page, then you'll obviously need to buy the book
  644. [00:52:50] <Mastermnd> vivekanada: remember you always have google too... if you type just that plus the word "sqlite" and "example" you'll get tons :P
  645. [00:52:52] --> mja5 (ad48adaa@gateway/web/freenode/ip.173.72.173.170) has joined #stanford-databases
  646. [00:52:59] <Benedict_> tought there was class today
  647. [00:53:20] <Vivekananda> Benedict_: again what class? class for what ?
  648. [00:53:29] <Guest41116> @<garrett_schlesin>:  how do you open the JSON file in a browser so that you have the option to expand as Jennifer did in the video?
  649. [00:53:31] <Benedict_> Rational database
  650. [00:53:35] <-- danielkessler (~danielkes@c-24-22-210-222.hsd1.wa.comcast.net) has quit (Quit: danielkessler)
  651. [00:53:47] <garrett_schlesin> Vivekananda: the best way to find a max is to 1) find everything that is less than something 2) subtract that result from the list of everything
  652. [00:53:47] <drostie> Vivekananda: strings are compared *lexicographically*. So "a" < "abc" < "ac".
  653. [00:54:14] <pattdaddy> Benedict_, you can log in to class anytime :)
  654. [00:54:17] <-- aeh (~aeh@76-250-90-115.lightspeed.austtx.sbcglobal.net) has left #stanford-databases
  655. [00:54:25] <Benedict_> ok
  656. [00:54:45] <pdub79> Thanks, Garrett.  That's what I was wanting to confirm with my textbook question.  I want to do the reading.
  657. [00:54:48] <Vivekananda> question: What is the level for the extra problems considering regulars as 2 and challenging as 5 -6
  658. [00:54:50] <nadrimajstor> Vivekananda: Luke use the join
  659. [00:54:51] <tommy1975> Hi Garret
  660. [00:54:53] <cpw> is this IRC going to be a regular Thursday thing?
  661. [00:54:58] --> Paco_ (bdfe75cc@gateway/web/freenode/ip.189.254.117.204) has joined #stanford-databases
  662. [00:55:02] <-- Pam (ae3f6015@gateway/web/freenode/ip.174.63.96.21) has quit (Ping timeout: 245 seconds)
  663. [00:55:05] <moko1> garrett_schlesin: which book that be again please?
  664. [00:55:06] <-- toocwa (toocwa@109.170.141.89) has quit
  665. [00:55:11] <Benedict_> pattdady was thinking it has a specific time for live class
  666. [00:55:13] <Vivekananda> Benedict_: are you taking about the hangout ??
  667. [00:55:21] <drostie> Guest41116: depends on the browser, but in Firefox use the JS console or the Firebug extension; in chrome/chromium use the JS console.
  668. [00:55:23] <Vivekananda> google plust ?
  669. [00:55:30] <tent405> garrett_schlesin: i still don't understand.. to find the most expensive pizza(s).. using RA.. i'm still clueless on how that could be done
  670. [00:55:35] <-- Souj (3cf0180f@gateway/web/freenode/ip.60.240.24.15) has quit (Quit: Page closed)
  671. [00:55:40] <Guest41116> @drostie: thanks!  trying it now.
  672. [00:55:45] <Vivekananda> tent405: I got it
  673. [00:55:46] <garrett_schlesin> Guest41116: I recommend using the JSONView plugin on Chrome
  674. [00:55:52] --> jane2 (~Adium@171.66.45.205) has joined #stanford-databases
  675. [00:55:53] <Vivekananda> :)
  676. [00:55:56] <-- RussiaM (~dataengin@act181-77.ucsd.edu) has quit
  677. [00:55:57] <tommy1975> I am actually struggling on Reletional Design Theory!
  678. [00:56:28] <tommy1975> It is pretty hard to find solutions
  679. [00:56:41] <garrett_schlesin> tent405: you compute the max using a set difference
  680. [00:56:43] <nadrimajstor> I am actually clueless what relational design theory is :(
  681. [00:56:49] <garrett_schlesin> you have the set of everything
  682. [00:56:57] <Vivekananda> Benedict_: I was thoroughly confused :) sorry about that
  683. [00:57:01] <Paco_> How can I get the trasncription of this sesion ?
  684. [00:57:20] <tent405> right, that's just the serves relation itself
  685. [00:57:23] <-- Guest41116 (d0b91272@gateway/web/freenode/ip.208.185.18.114) has quit (Quit: Page closed)
  686. [00:57:23] <cpw> Hi, will there be 'Office Hours' via IRC regularly on Thursdays, 2:30 to 4:00PM?
  687. [00:57:24] <flosakura> does anyone have a log of the whole office hour? i came in late. :)
  688. [00:57:24] <Vivekananda> Paco_: One way is to log the session in your irc client
  689. [00:57:25] <Benedict_> viviekanada_ no problem
  690. [00:57:29] <garrett_schlesin> and you can compute the set of things that are less than something else by doing a cross product of the set with itself and filtering
  691. [00:57:45] <garrett_schlesin> then, you can compute the max using a difference between these two sets
  692. [00:57:51] <tent405> ahhhhh that's where cross product is important i was wondering when i'd have to use it
  693. [00:57:52] <Paco_> Thanks Vivekanada
  694. [00:57:57] <-- piksu (a689bf21@gateway/web/freenode/ip.166.137.191.33) has quit (Ping timeout: 245 seconds)
  695. [00:58:11] <tent405> i think that was briefly discussed in the video i'll have to go back and look
  696. [00:58:23] <garrett_schlesin> i.e. the max is just something that is not less than anything else
  697. [00:58:29] <nadrimajstor> garrett_schlesin: Spoilers :p
  698. [00:58:32] --> NoBasis (6303ac46@gateway/web/freenode/ip.99.3.172.70) has joined #stanford-databases
  699. [00:58:44] <Mastermnd> tent405: it's also important when you want to present two unrelated values horizontally, for example
  700. [00:58:50] --> danielhegarty (~danielheg@cpe-76-170-95-174.socal.res.rr.com) has joined #stanford-databases
  701. [00:58:52] <garrett_schlesin> cpw: I will have office hours every Thursday from 2:30-4pm
  702. [00:59:01] <garrett_schlesin> they won't always be on IRC, though
  703. [00:59:07] <drostie> Mastermnd: which is important in the last two challenges. ^_^
  704. [00:59:08] <Vivekananda> the Professor's lectures are getting more and interesting to me coz I find that if I miss a line or a word I might end up missing a problem
  705. [00:59:23] <garrett_schlesin> I'm going to experiment with different ways of holding office hours and see what works best
  706. [00:59:45] <-> moko1 is now known as mokocha
  707. [00:59:52] <drostie> Vivekananda: you may find it helpful to watch lectures multiple times because usually the brain works by reinforcing associations rather than absorbing information.
  708. [00:59:59] <flosakura> garrett_schlesin: what other formats are you thinking?
  709. [01:00:02] <Vivekananda> garrett_schlesin: I have already solved the question with the hints you gave to tent405 above I am just wondering how I am supposed to come up with it by myself :(
  710. [01:00:03] <nadrimajstor> I'm going to experiment with few thousends studnes :D
  711. [01:00:07] <-- stater (d852f354@gateway/web/freenode/ip.216.82.243.84) has quit (Quit: Page closed)
  712. [01:00:16] <Mark_> garrett_schlesin: is a crossproduct an O(n^2) operation for time and space?  it seems a bit impractical if the db is large?
  713. [01:00:19] <Benedict_> vivekanada_can u help me with the materials u got, my internet is slow here
  714. [01:00:22] <garrett_schlesin> I'm glad I could do this session!
  715. [01:00:29] <garrett_schlesin> I need to go to class now
  716. [01:00:30] <drostie> Vivekananda: you're supposed to be creative and it's supposed to be challenging.
  717. [01:00:31] <Vivekananda> sure what do you need
  718. [01:00:37] <garrett_schlesin> good luck to all, and I'll see you next week
  719. [01:00:37] <tommy1975> cross product renaming attributes then selection attrib1 < attrib2 eliminating the duplicate then (list of attrib1) /diff (list of attrib2) u got the max
  720. [01:00:38] <Vivekananda> where are you
  721. [01:00:40] <flosakura> thanks garrett_schlesin
  722. [01:00:43] --> yam_ (62cf92fa@gateway/web/freenode/ip.98.207.146.250) has joined #stanford-databases
  723. [01:00:44] <Vivekananda> drostie: yeah I guess :) :)
  724. [01:00:51] <AndyKay> Thank you for visiting us, garrett_schlesin
  725. [01:00:52] <Mastermnd> Mark_ n*m but close  to n^2 so yeah, it's expensive
  726. [01:00:57] <-- NoBasis (6303ac46@gateway/web/freenode/ip.99.3.172.70) has quit (Client Quit)
  727. [01:00:58] <Vivekananda> drostie: are you a TA too ?
  728. [01:01:00] <-- fullondan (~danielheg@cpe-76-170-95-174.socal.res.rr.com) has quit (Ping timeout: 252 seconds)
  729. [01:01:02] <LightKnight> thanks garrett_schlesin, until next time :)
  730. [01:01:04] <garrett_schlesin> (I might try an AMA on Reddit, for the curious… I'll send out an official announcement with details later this week)
  731. [01:01:06] <nadrimajstor> garrett_schlesin: bye
  732. [01:01:16] <Vivekananda> Benedict_: what do you need ?
  733. [01:01:16] <drostie> I am not a TA for this course but I've been helping people in this chat whenever possible. ^_^
  734. [01:01:16] <Mastermnd> thanks garrett
  735. [01:01:18] <brian_> thanks garrett
  736. [01:01:19] <AndyKay> Oh, AMA would be cool!
  737. [01:01:28] <drostie> yeah, thanks garrett, enjoy class.
  738. [01:01:35] <AndyKay> The 2nd A means anything, garrett_schlesin, hope you know it :)
  739. [01:01:37] <BethMonk> Thanks Garrett
  740. [01:01:39] <flosakura> garrett_schlesin: we had a google+ hangout studysession... worked really well since we can hav eplugins to show each other screens and type out the database on excel
  741. [01:01:44] <Vivekananda> thanks garrett_schlesin
  742. [01:01:44] --> NaN123 (~Thunderbi@186.31.108.218) has joined #stanford-databases
  743. [01:01:51] <-- NaN123 (~Thunderbi@186.31.108.218) has quit (Client Quit)
  744. [01:02:01] <Adriana> Thank you Garrett
  745. [01:02:01] <-- nadrimajstor (b2955987@gateway/web/freenode/ip.178.149.89.135) has quit (Quit: Page closed)
  746. [01:02:03] <-- brian_ (~quassel@72.252.195.130) has quit (Quit: http://quassel-irc.org - Chat comfortably. Anywhere.)
  747. [01:02:14] <-- Adriana (be0a3892@gateway/web/freenode/ip.190.10.56.146) has left #stanford-databases
  748. [01:02:16] <Benedict_> vivekanada video of the lecture and some clue on issue resolution
  749. [01:02:45] <Jaak1946> Thank you, Garrett
  750. [01:02:46] <Mark_> Thanks Garrett
  751. [01:02:47] <-- garrett_schlesin (~Adium@171.66.46.183) has quit (Quit: Leaving.)