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AWS-SAA-C02-Study-Guide
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Small rephrasing

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Luca-Dorin Anton 2022-09-24 15:09:56 +01:00
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@ -946,7 +946,7 @@ Amazon DynamoDB is a key-value and document database that delivers single-digit
- DynamoDB is stored via SSD which is why it is so fast.
- It is spread across 3 geographically distinct data centers.
- The default consistency model is Eventually Consistent Reads, but there are also Strongly Consistent Reads.
- The difference between the two consistency models is the one second rule. With Eventual Consistent Reads, all copies of data are usually reached within one second. A repeated read after a short period of time should return the updated data. However, if you need to read updated data within or less than a second and this needs to be a guarantee, then strongly consistent reads are your best bet.
- The difference between the two consistency models is the one second rule. With Eventual Consistent Reads, all copies of data are usually identical within one second after a write operation. A repeated read after a short period of time should return the updated data. However, if you need to read updated data within or less than a second and this needs to be a guarantee, then strongly consistent reads are your best bet.
- If you face a scenario that requires the schema, or the structure of your data, to change frequently, then you have to pick a database which provides a non-rigid and flexible way of adding or removing new types of data. This is a classic example of choosing between a relational database and non-relational (NoSQL) database. In this scenario, pick DynamoDB.
- A relational database system does not scale well for the following reasons:
- It normalizes data and stores it on multiple tables that require multiple queries to write to disk.