junegunn commented on PR #8485:
URL: https://github.com/apache/hbase/pull/8485#issuecomment-5140585810

   The history behind this issue is quite involved, so I don't feel confident 
making a judgment call on my own. From what I understand, this patch was first 
suggested by Lars Hofhansl in early 2013:
   
   - 
https://issues.apache.org/jira/browse/HBASE-6562?focusedCommentId=13543488&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13543488
   
   He raised a concern about the performance impact of eager seeks, but the 
question was never answered. Adding `hasFilterRowKey` was briefly discussed as 
a way to limit the cases where the lazy seek optimization is lost, but the 
community never reached a consensus.
   
   So the question still remains. Do you have a view on the performance impact?
   
   The eager seek is once per scanner open rather than per row, and scans 
without explicit columns already take that path, so it may well be fine. But it 
applies to every filtered explicit-column non-Get scan, so we should understand 
the cost before making it the default.
   
   To be clear, I am not suggesting we leave the bug unfixed. Correctness 
should take priority over performance. I would just like to understand the cost 
before we commit.
   


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