WEBVTT 00:07.700 --> 00:10.130 I will call you back again tonight after the lecture in Moscow. 00:10.130 --> 00:11.450 And in this video lecture. 00:11.450 --> 00:15.320 Let's go ahead and look at index and MySQL. 00:15.320 --> 00:21.320 So index is known as a B-tree data structure. 00:21.320 --> 00:27.800 And it is used to find values within a specific column easily and fast because MySQL actually searches 00:27.800 --> 00:30.050 the data sequentially through a column. 00:30.050 --> 00:35.660 So this is going to be a quick lecture because we don't have a very large list. 00:35.660 --> 00:41.000 So this is just a few of our just like seven rows under here. 00:41.000 --> 00:42.140 So it's going to be a quick one. 00:42.140 --> 00:46.070 But it's very important if you are dealing with a very large set of data. 00:46.070 --> 00:51.740 So imagine you have like millions of these employees and we have just several right here. 00:51.770 --> 00:54.080 So that is why you're not going to take much time. 00:54.080 --> 00:58.040 So that's why I don't show the current index of our table. 00:58.040 --> 01:03.920 So to show the current index of this table we go ahead and say show index six. 01:04.580 --> 01:10.970 So should index six from then employees. 01:11.630 --> 01:13.880 So place semicolon and go ahead and run this race. 01:13.880 --> 01:14.600 Check it out. 01:14.600 --> 01:18.260 And now we can see we have this uh index curl. 01:18.260 --> 01:23.900 And now you can see it is a B3 or B3 and all new colors and is visible. 01:23.900 --> 01:25.130 And now. 01:27.230 --> 01:30.410 That is the supervisor of the index is home. 01:30.410 --> 01:32.000 And the first name is key. 01:32.270 --> 01:34.160 You can see the key name is first name. 01:34.160 --> 01:35.750 And the column name is first name. 01:35.750 --> 01:39.650 The coalition is a and the cardinality is six. 01:39.950 --> 01:43.850 Oh and now let's go ahead and create index for this first name. 01:43.850 --> 01:44.750 That is it. 01:44.780 --> 01:47.000 Right in here you can actually create index. 01:47.000 --> 01:50.780 And if you help us to actually speed up the search of our database. 01:50.780 --> 01:55.640 But one thing is that the database we have is just a smaller database. 01:55.640 --> 02:01.340 So the search might not be that visible to you because it's just seven rows. 02:01.340 --> 02:04.580 But if you have millions of it, it's going to make more sense to us. 02:04.580 --> 02:06.650 So that's why I said it's going to be a quick lecture. 02:06.680 --> 02:09.620 Now let's go ahead and create index for the first name. 02:09.620 --> 02:14.420 So go ahead and remove this and I'll go ahead and say create index. 02:15.050 --> 02:17.360 And uh for the first name. 02:17.360 --> 02:20.720 So first underscore name. 02:20.720 --> 02:23.180 So that is going to be the name of the index. 02:23.180 --> 02:27.920 So we just created the first underscore index on employee. 02:28.460 --> 02:34.520 So employees and the index want to create this for the column this column called first name. 02:34.520 --> 02:42.830 So go ahead and insert that first underscore name and go ahead and put a semicolon at the end of this. 02:42.860 --> 02:44.270 Go ahead and execute this query. 02:44.270 --> 02:47.210 And you can see that our index is created. 02:47.210 --> 02:50.720 So now let's go ahead and show this index that we just created. 02:50.720 --> 02:58.190 So I'll go ahead and say show index six show index six. 02:58.190 --> 03:05.330 So from the employees table so employees for a semicolon at end. 03:05.360 --> 03:05.990 And let's go ahead. 03:05.990 --> 03:13.250 And as a kid that so you can see we have our employees one and the index that we just created which 03:13.280 --> 03:16.160 is first underscore name underscore ADX. 03:16.160 --> 03:18.530 And I can see it sequentially. 03:18.530 --> 03:22.520 And uh that is it right here. 03:23.000 --> 03:28.280 Now if you go ahead and uh check out we want to search your table. 03:28.310 --> 03:32.630 So let's go ahead and say you want to search the employee table by the first name, which you have us 03:32.630 --> 03:40.760 to speed our search for a name under employee, maybe Peter, Mark, global, Steve, Michael or anyone. 03:40.790 --> 03:47.720 You go ahead and say select uh, all from the employee. 03:47.840 --> 03:50.540 And then we go ahead and we are close. 03:50.540 --> 03:57.380 So we are the first underscore name is equal to. 03:57.410 --> 03:59.180 Let me go ahead and say press semicolon. 03:59.180 --> 04:02.510 So you can go ahead and insert in maybe George anyone. 04:02.540 --> 04:05.510 So let me say George and go ahead and check it out. 04:05.510 --> 04:07.670 And uh, this is George. 04:08.780 --> 04:11.150 Now you might not make sense to us. 04:11.150 --> 04:16.520 That is why I said that, uh, this is a smaller table, and the search is very fast because we're not 04:16.550 --> 04:21.020 dealing with a large set of data, but we are dealing with a large set of data like millions of that. 04:21.020 --> 04:27.230 And imagine companies that have like six millions, uh, maybe students and so on. 04:27.230 --> 04:30.320 And you are trying to create the database. 04:30.320 --> 04:33.590 The index will actually help you to do it, to be fast. 04:33.620 --> 04:34.100 All right. 04:34.130 --> 04:39.380 But because you have a smaller database which you are using in this lecture, the search is always fast 04:39.380 --> 04:42.110 and you might not actually see the results. 04:42.110 --> 04:43.340 So this is about indexing. 04:43.520 --> 04:47.660 We're not going to talk much on that because I dealt with like a small data set here. 04:47.660 --> 04:50.810 But you can go deep into that and check more about it. 04:50.810 --> 04:53.330 So for now we're going to stop at index. 04:53.330 --> 04:58.760 And uh you go ahead and look more into that with large data set and see what it gives you. 04:58.790 --> 05:00.920 So at the end that is it for now. 05:00.920 --> 05:02.000 So go ahead and check it out. 05:02.180 --> 05:02.720 Done with it. 05:02.720 --> 05:05.270 And if you have any questions please use the question and answer section. 05:05.270 --> 05:07.400 And I'm going to get back to you as soon as possible. 05:07.430 --> 05:08.240 Thank you so much. 05:08.240 --> 05:11.240 And I'm going to see you in the next video lecture.