SHA256
20 lines
601 B
Markdown
20 lines
601 B
Markdown
# Read / Write Capacity Units
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This is for [[_DynamoDB|DynamoDB]].
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The general formula for $CU$s is
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$$
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\begin{aligned}
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rHz =& \frac{kCU / m}{ceil(nKB/bKB)} \\\ \\
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kCU =& ceil(nKB / bKB) \times rHz \times m \\\ \\
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\text{where:} \\
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nKB =& \text{ input size in KB} \\
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bKB =& \text{ operation block size: 1KB for Writes and 4KB for Reads} \\
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rHz =& \text{ request rate} \\
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m =& \text{ modifier: } \\
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&0.5\text{ for eventually consistent operations, } \\
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&1\text{ for normal operations, } \\
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&2\text{ for transactional operations}
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\end{aligned}
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$$
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See [[Read and Write Units - Set 3]] for some examples.
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