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In this video, we are going to learn query and scan operations on dynamic DB table.

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You remember that when we are working with the management console, we have to option scan and query.

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When we click the query, we have to provide the primary key.

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In this table there is only one primary key, which is the partition key is ID.

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So if you look at the documentation, there is a Dynamo DB API reference documentation.

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You can see that query and second operation is a Dynamo DB API that we can call from the any resources

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like a SLI management console or SDK.

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So in these videos we will query and scan operation from the HTK libraries.

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So what is the query?

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Query is basically points item in the table with looking the primary key attributes.

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So if the primary key has only part sync, it is required part sync.

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If it is two items with partition and sort k, it is requiring both two items with partition and the

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sort.

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K So we have to provide a partition, key name and volume for which search will be performed.

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And we can also provide a third key name and value and use the comparison operators to define results

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of the search.

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So scanning finds the items by checking every item in the specified table.

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So there is a big difference with the query and scan.

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If you click the scan operation, you can see that.

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Before that I would like to show the query operation.

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If you scroll down, you can see the request syntax that we can provide these attributes.

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One Running to query operation.

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By using the SSC, we will provide this kind of input, these kind of attributes.

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So, for example, key conditions, fit exhibitions and so on.

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So if we go to scan operations and compare, this can be to create operations.

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Basically this scan operation returns one or more items and item attributes by accessing every item

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in the table.

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And this is very important because scan operation is very costly service that we cannot use, that we

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should not use every operation.

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And if we use the scan operation, it is basically scanning all items in the table and return back to

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us, the whole results.

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So as you can see that this is the scan operation.

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If you scroll on, you can see the request syntax of the scan operation.

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We can use these attribute values when sending this scan dynamic DB API.

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So in the next video we will send query and scan command from our Node.js application.

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We use the SDK libraries.