TheR1sing3un commented on issue #11715:
URL: https://github.com/apache/hudi/issues/11715#issuecomment-2264428887

   > @TheR1sing3un hi, this is a great capability, but before starting, it is 
necessary to confirm in which scenarios it can bring benefits. Could you 
provide a few scenarios?
   
   > Assume the following scenario
   
   - some high-frequency keys are updated frequently
   - the first appearance of these keys in log files came relatively late
   - MaxMemoryForCompaction relatively small
   
   When a Compaction/Log-Compaction happens and these keys were not initially 
loaded into the memory map,  the subsequent frequent 'get' in compaction logic 
results in a large number of random reads on the disk (both `bitcask` and 
`rocksdb` are log-structure-append-only-file data structure, high performance 
for reading but low performance  for writing), which will cause great 
performance degradation. If the map in the memory has a certain elimination and 
update mechanism, such as lru or lfu, the memory hit ratio will be improved in 
some scenarios for better compaction performance.


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