1 00:00:00,000 --> 00:00:04,000 At the end of Unit 4, we built a search index that could respond to queries 2 00:00:04,000 --> 00:00:07,000 and would do this by going through each entry one at a time, 3 00:00:07,000 --> 00:00:10,000 checking if the keyword matched the word we were looking for, 4 00:00:10,000 --> 00:00:13,000 and then responding with a result for that. 5 00:00:13,000 --> 00:00:17,000 I wanted to ask Gabriel Weinberg, the creator of DuckDuckGo, how well that approach will work 6 00:00:17,000 --> 00:00:20,000 if we have a large index with lots of queries. 7 00:00:20,000 --> 00:00:24,000 You'll find that with a large index with lots of queries, it will be too slow. 8 00:00:24,000 --> 00:00:28,000 A typical search engine should respond in under a second and often times much faster. 9 00:00:28,000 --> 00:00:33,000 But with that algorithm, having to go through each link like that one after the other, 10 00:00:33,000 --> 00:00:36,000 you could be on the order of seconds or even longer. 11 00:00:36,000 --> 00:00:39,000 So what we're going to learn this unit is how to make this much faster.