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Published inSep 2014
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ISBN-139781783551897
Edition1st Edition
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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...

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DynamoDB Applied Design Patterns
Published in: Sep 2014Publisher: ISBN-13: 9781783551897