1 00:00:01,440 --> 00:00:07,280 In the last lecture we created our first table using the AWOS gone. 2 00:00:07,290 --> 00:00:11,550 So let's look at some item level operations in this video. 3 00:00:15,040 --> 00:00:25,150 If you work with relational databases before you may have noticed that we did not specify the names 4 00:00:25,150 --> 00:00:29,910 of all the columns are all the item attributes. 5 00:00:30,010 --> 00:00:38,730 This is because unlike relational databases dynamo DBI does not enforce strict schema. 6 00:00:41,040 --> 00:00:50,370 Only the primary key attributes are mandatory and all other attributes including the ones that are used 7 00:00:50,430 --> 00:00:53,830 in the secondary access are optional. 8 00:00:53,980 --> 00:01:01,680 So one item in Dynamo table could have two attributes right and another atom in the same table could 9 00:01:01,680 --> 00:01:09,810 have 10 attributes for example and both would still be valid items as long as they have the primary 10 00:01:09,810 --> 00:01:17,280 key attributes included if any item does not have a value for a secondary index key. 11 00:01:17,310 --> 00:01:23,570 It will simply be excluded from that particular index and will see this in action. 12 00:01:23,580 --> 00:01:24,290 In this video 13 00:01:27,360 --> 00:01:31,060 let's add some data to our lives table. 14 00:01:32,280 --> 00:01:34,850 Click on the items tab. 15 00:01:35,790 --> 00:01:38,910 Click on the Create item button to add data. 16 00:01:43,720 --> 00:01:52,640 We can simply free let the keys and values here and we can use the plus sign on the left to insert apin 17 00:01:52,700 --> 00:02:02,300 or remove an atom insert as an attribute about the current attribute Aben as set after the current attribute 18 00:02:02,570 --> 00:02:07,910 and the Remove will simply remove IDE tribute from the. 19 00:02:08,160 --> 00:02:17,910 If you prefer the Chaisson format you can switch from tree to text and you can edit or pasting some 20 00:02:17,910 --> 00:02:18,980 Jason here. 21 00:02:20,570 --> 00:02:29,690 If you use dynamo DBI Jason checkbox you'll see that Dynamo the beacon works these days and into its 22 00:02:29,780 --> 00:02:41,450 own internal format which includes the data type as the search string is denoted by an uppercase s number 23 00:02:41,450 --> 00:02:49,270 by an upper case n binary by uppercase B and so on set. 24 00:02:49,400 --> 00:02:51,750 Let's add some dummy data. 25 00:02:59,060 --> 00:03:00,330 For a user ID. 26 00:03:00,330 --> 00:03:07,120 I'm just rolling some keys on my keyboard to get some random value. 27 00:03:07,140 --> 00:03:09,060 Same for no tidy 28 00:03:18,520 --> 00:03:19,730 four times. 29 00:03:19,770 --> 00:03:29,760 Dan let's grab the current epoch times down around Unix time stamp dot com and it 30 00:03:59,510 --> 00:04:07,550 and then we also want to add a content attribute to hold the main text of our no 31 00:04:16,330 --> 00:04:28,510 click on Save to save the item and we have one item you can edit the non-key it to be is in line using 32 00:04:28,510 --> 00:04:29,610 the pencil. 33 00:04:29,650 --> 00:04:40,980 I can hear or simply click on the blue hyperlink to edit it in the editor action Stabb has options like 34 00:04:40,980 --> 00:04:46,270 duplicate item added deleted exported to CSB. 35 00:04:46,290 --> 00:04:53,690 And these are pretty much exactly do what they say manage. 36 00:04:53,690 --> 00:05:00,710 TTL is something will cower in the later part of the course. 37 00:05:00,890 --> 00:05:09,150 So I'm going to use the duplicate option to add some more dummy data here. 38 00:05:09,950 --> 00:05:17,360 And we just have to provide a new primary key values and maybe change some other attributes if we like 39 00:05:33,850 --> 00:05:36,450 and we should have a couple of items. 40 00:05:39,180 --> 00:05:47,180 Now I'm going to duplicate an item and this time I'm going to drop the note ID attribute 41 00:05:58,100 --> 00:06:07,550 and one item where I'll drop the category attribute. 42 00:06:08,220 --> 00:06:15,280 Now if you notice these attributes are part of the global and local. 43 00:06:15,300 --> 00:06:16,910 Second the next keywords. 44 00:06:16,930 --> 00:06:26,780 So if we don't get them from any item that particular item will be omitted from the corresponding index. 45 00:06:26,830 --> 00:06:30,800 Let me show you what I am from the dropdown. 46 00:06:30,910 --> 00:06:34,540 Let's select the note Id index. 47 00:06:34,540 --> 00:06:38,520 This is our global secondary index right. 48 00:06:38,600 --> 00:06:49,690 Note ID has the partition key take Star Search and you'll notice that the item with the note id attribute 49 00:06:49,810 --> 00:06:51,750 is not showing up here. 50 00:06:52,030 --> 00:07:00,100 Similarly if we select our local secondary next that has category as the sarky. 51 00:07:00,140 --> 00:07:06,120 You'll notice that the item with no category is not part of this index. 52 00:07:07,640 --> 00:07:15,730 Now let's get back to the primary index are the table index and hit search. 53 00:07:15,960 --> 00:07:19,660 And here we see old items in our table 54 00:07:25,200 --> 00:07:31,590 if we add more columns are more attributes to the items. 55 00:07:31,590 --> 00:07:41,490 The display sometimes gets slightly cluttered so we get hide or show the design columns using the gear 56 00:07:41,570 --> 00:07:44,250 icon on the top right here. 57 00:07:52,850 --> 00:07:57,290 Now let's look at how to blow from reeds. 58 00:07:57,290 --> 00:07:58,770 There are two ways. 59 00:07:59,000 --> 00:08:10,000 Query and can let's select query first we have to specify the index to be used. 60 00:08:10,070 --> 00:08:20,340 We can query using that table index are the primary key or any of the secondary indexes that we created. 61 00:08:20,690 --> 00:08:31,390 Let's use the table index with the operations you must specify the partition key value. 62 00:08:31,390 --> 00:08:38,450 We have to specify the entire partition key and sarky is optional. 63 00:08:38,890 --> 00:08:49,290 In other words what this also means is query operation performs a search within a single partition. 64 00:08:50,170 --> 00:08:55,030 If I say user ID equals this and search 65 00:08:59,210 --> 00:09:01,580 Rishabh see all the matching items. 66 00:09:01,580 --> 00:09:10,090 And since they all have the same partition key they will be stored in the same partition. 67 00:09:10,460 --> 00:09:20,540 By default These will be sorted by the sarky of the selected index and we can switch the sort order 68 00:09:20,630 --> 00:09:22,050 using the sort. 69 00:09:22,060 --> 00:09:23,210 The radio button here 70 00:09:30,610 --> 00:09:36,020 we can also specify as sarky to narrow down our search. 71 00:09:36,310 --> 00:09:40,500 We can't specify sarky in different ways. 72 00:09:40,630 --> 00:09:48,280 For example we can use combatives and operators equal to greater than between and so on. 73 00:09:48,280 --> 00:09:56,210 Similarly if our key is strong for example let's select the category index. 74 00:09:56,220 --> 00:10:03,140 So with string based sarky we have one more option begins with. 75 00:10:03,380 --> 00:10:12,400 So these are different ways we can narrow down our search and mission or we could also specify a filter 76 00:10:12,400 --> 00:10:18,550 or criteria filter criteria as typically is to filter our data. 77 00:10:18,570 --> 00:10:25,220 What conditions are conditions on non-key attributes. 78 00:10:25,860 --> 00:10:36,270 An important thing to remember here is filters are always filters are always applied after performing 79 00:10:36,270 --> 00:10:37,770 the query. 80 00:10:38,070 --> 00:10:47,610 Dynamo divi performs the raid using the specified index criteria and once it has retrieved the data 81 00:10:47,700 --> 00:10:56,410 it filters set according to the filter criteria provided before returning the data to us. 82 00:10:56,460 --> 00:11:06,540 What this means is specifying one or more filters will not affect they are consumed by the particular 83 00:11:06,540 --> 00:11:07,890 read operation. 84 00:11:08,040 --> 00:11:15,250 You still can zoom the same number of hours to use whether you use a filter or you don't. 85 00:11:15,260 --> 00:11:19,170 So filter is just a convenience feature. 86 00:11:19,170 --> 00:11:22,920 So to say let's look at this. 87 00:11:22,920 --> 00:11:29,600 Can operation select scan from the drop down and hit search. 88 00:11:29,650 --> 00:11:33,250 So we select an index and hit search. 89 00:11:33,490 --> 00:11:36,960 And we should see the corresponding data 90 00:11:39,980 --> 00:11:47,560 and since we selected the table index we'll see all the items in the table up to 100 added time 91 00:11:50,480 --> 00:11:58,280 unlike Curti which provides us data from the partitions specified by the partition key scan operation 92 00:11:58,280 --> 00:12:05,970 can provide us data across partitions and just like operations. 93 00:12:05,990 --> 00:12:11,700 We can also specify filters in the same way for our scanner operations as well. 94 00:12:14,790 --> 00:12:23,600 And again the filters get applied only after performing these can serve dynamo IDB performs the read 95 00:12:23,610 --> 00:12:32,100 first and once it has retrieved the data it filters said according to the filter criteria that is specified 96 00:12:32,460 --> 00:12:42,480 before it returns the data to us and since scanner operations perform so chairs across the table partitions 97 00:12:42,510 --> 00:12:47,250 they can use the read capacity and it's very very fast. 98 00:12:47,280 --> 00:12:54,160 And that is the reason we should avoid using scan operations as far as possible. 99 00:12:54,300 --> 00:12:57,970 And Bradford the cruddy operations for our purposes 100 00:13:01,130 --> 00:13:02,690 this is the reason why. 101 00:13:02,730 --> 00:13:13,760 Well our data modeling is very crucial when working with Dynamo D-B we should choose table keys and 102 00:13:13,790 --> 00:13:24,380 indexes ready carefully considering all the different possibilities of the operations that our application 103 00:13:24,380 --> 00:13:29,150 might need to perform now as well as in future. 104 00:13:29,390 --> 00:13:39,020 So we must think ahead of time and also consider any possible future use cases. 105 00:13:39,020 --> 00:13:46,760 So we are not forced to recreate the whole table if any is case arises in future. 106 00:13:50,200 --> 00:13:56,670 That's more or less all about the item level operations in Dannemora maybe in the next lecture. 107 00:13:56,710 --> 00:14:07,150 I'll walk you through the different options we have on these tabs on the dynamo or the console so. 108 00:14:07,330 --> 00:14:13,510 Thank you for your time and I'll see you in the next Vidia in just a few moments.