Search CTRL + K

Read Amplification

#IT/System

读放大 是指实际读取操作次数大于逻辑上需要读的次数。

和 写放大 对比

写放大 关注写入 数据量（write bytes），读放大 关注读取 操作数（read、seek）。

读放大 对点查询和范围查询有不同的定义，对于范围查询来说，读取行数的增加更重要。


Read amplification is the number of disk reads per query.

Note that the units of write amplification and read amplification are different. Write amplification measures how much more data is written than the application thought it was writing, whereas read amplification counts the number of disk reads to perform a query.

SLSM - A Scalable Log Structured Merge Tree with Bloom Filters for Low Latency Analytics

Read amplification is the number of I/O’s required to satisfy a particular query. There are two important cases for read amplification: cold cache, and warm cache.[2]

  1. https://tikv.org/deep-dive/key-value-engine/b-tree-vs-lsm/#read-amplification ↩︎

  2. P.A. Riyaz and Surekha Mariam Varghese, “SLSM - A Scalable Log Structured Merge Tree with Bloom Filters for Low Latency Analytics,” Procedia Technology 24 (2016): 1491–98, https://doi.org/10.1016/j.protcy.2016.05.075. ↩︎