Question

What search technology does Q2A use ?

Answer 1

Q2A uses its own search method. Basically, every word from every post is indexed (in qa_words and qa_contentwords), so that when you search for a word, it finds the ID from qa_words, then grabs all the posts in qa_contentwords that have the word in it.

I don't know exactly how questions are ordered and prioritized though, gidgreen can probably answer that.

Answer 2

I cheched its search SQL,use keyword as "all questions".You can see below:

SELECT qa_posts.postid, qa_posts.categoryid, qa_posts.type, LEFT(qa_posts.type, 1) AS basetype, INSTR(qa_posts.type, '_HIDDEN')>0 AS hidden, qa_posts.acount, qa_posts.selchildid, qa_posts.closedbyid, qa_posts.upvotes, qa_posts.downvotes, qa_posts.netvotes, qa_posts.views, qa_posts.hotness, qa_posts.flagcount, qa_posts.title, qa_posts.tags, UNIX_TIMESTAMP(qa_posts.created) AS created, qa_categories.title AS categoryname, qa_categories.backpath AS categorybackpath, qa_posts.userid, qa_posts.cookieid, INET_NTOA(qa_posts.createip) AS createip, qa_userpoints.points, qa_users.flags, qa_users.level, qa_users.email AS email, qa_users.handle AS handle, qa_users.avatarblobid, qa_users.avatarwidth, qa_users.avatarheight, score, matchparts FROM qa_posts LEFT JOIN qa_categories ON qa_categories.categoryid=qa_posts.categoryid LEFT JOIN qa_users ON qa_posts.userid=qa_users.userid LEFT JOIN qa_userpoints ON qa_posts.userid=qa_userpoints.userid JOIN (SELECT questionid, SUM(score)+2*(LOG(10000)*(qa_posts.hotness-(SELECT MIN(hotness) FROM qa_posts WHERE type='Q'))/((SELECT MAX(hotness) FROM qa_posts WHERE type='Q')-(SELECT MIN(hotness) FROM qa_posts WHERE type='Q')))+LOG(questionid)/1000000 AS score, GROUP_CONCAT(CONCAT_WS(':', matchposttype, matchpostid, ROUND(score,3))) AS matchparts FROM ((SELECT postid AS questionid, LOG(10000/titlecount) AS score, 'Q' AS matchposttype, postid AS matchpostid FROM qa_titlewords JOIN qa_words ON qa_titlewords.wordid=qa_words.wordid WHERE word IN ('all','questions') AND titlecount<10000) UNION ALL (SELECT questionid, (1-1/(1+count))*LOG(10000/contentcount)*(CASE qa_contentwords.type WHEN 'Q' THEN 1.0 WHEN 'A' THEN 0.5 ELSE 0.25 END) AS score, qa_contentwords.type AS matchposttype, qa_contentwords.postid AS matchpostid FROM qa_contentwords JOIN qa_words ON qa_contentwords.wordid=qa_words.wordid WHERE word IN ('all','questions') AND contentcount<10000) UNION ALL (SELECT postid AS questionid, 2*LOG(10000/tagwordcount) AS score, 'Q' AS matchposttype, postid AS matchpostid FROM qa_tagwords JOIN qa_words ON qa_tagwords.wordid=qa_words.wordid WHERE word IN ('all','questions') AND tagwordcount<10000) UNION ALL (SELECT postid AS questionid, LOG(10000/qposts) AS score, 'Q' AS matchposttype, postid AS matchpostid FROM qa_posts JOIN qa_users ON qa_posts.userid=qa_users.userid JOIN qa_userpoints ON qa_userpoints.userid=qa_users.userid WHERE handle IN ('all','questions') AND type='Q') UNION ALL (SELECT postid AS questionid, LOG(10000/qposts) AS score, 'Q' AS matchposttype, postid AS matchpostid FROM qa_posts JOIN qa_users ON qa_posts.userid=qa_users.userid JOIN qa_userpoints ON qa_userpoints.userid=qa_users.userid WHERE handle='all questions' AND type='Q')) x LEFT JOIN qa_posts ON qa_posts.postid=questionid GROUP BY questionid ORDER BY score DESC LIMIT 0,21) y ON qa_posts.postid=y.questionid

Answer 3

platform is based on PHP, Apache, MySQL

theme uses Jquery and you can add other things like Flash,Silverlight, ... with advanced theme.

just search your site with woorank.com and it will show you technolegy and snippets used in your site.