Book Image

DynamoDB Applied Design Patterns

By : Uchit Hamendra Vyas
Book Image

DynamoDB Applied Design Patterns

By: Uchit Hamendra Vyas

Overview of this book

Table of Contents (17 chapters)
DynamoDB Applied Design Patterns
About the Authors
About the Reviewers

Parallel scanning

As we discussed in DynamoDB sharding, the table data is partitioned based on the hash key value. Even though this sharding will smoothen the read and write operations, it doesn't help us to scan the partitions in parallel. For example, if the table data is available in five partitions (each partition has a throughput capacity of five units), then even if the table could provision more than five capacity units, it cannot do so. The maximum throughput capacity of the table cannot exceed the fastest (having high throughput) partition. So based on these facts, what we infer is:

  • A scan operation will return maximum 1 MB of data at a time

  • Scan operations can read data from only one partition at a time

  • For a larger table, no matter how large the throughput is, a sequential scan will always take too much time

  • The scanning speed can never be faster than the fastest partition (having high throughput)

To put it simply, even if our television has one hundred channels, we will be able to...