[ 
https://issues.apache.org/jira/browse/LUCENE-10574?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17538746#comment-17538746
 ] 

Adrien Grand commented on LUCENE-10574:
---------------------------------------

I used BaseMergePolicyTestCase's simulation logic to run some tests with 10k 
docs, flushed 3 by 3 where each doc uses 10 bytes on disk:

|| || TieredMergePolicy's default || TieredMergePolicy with floo segment size = 
Double.MIN_VALUE || TieredMergePolicy constrained to never produce merges where 
the overal size of the merge is not at least 50% larger than the biggest input 
segment ||
|Write amplification| 94.0 | 3.6 | 7.7 |
|Average number of segments in the index| 6.0 | 24.4 | 6.7 |

> Remove O(n^2) from TieredMergePolicy or change defaults to one that doesn't 
> do this
> -----------------------------------------------------------------------------------
>
>                 Key: LUCENE-10574
>                 URL: https://issues.apache.org/jira/browse/LUCENE-10574
>             Project: Lucene - Core
>          Issue Type: Bug
>            Reporter: Robert Muir
>            Priority: Major
>
> Remove {{floorSegmentBytes}} parameter, or change lucene's default to a merge 
> policy that doesn't merge in an O(n^2) way.
> I have the feeling it might have to be the latter, as folks seem really wed 
> to this crazy O(n^2) behavior.



--
This message was sent by Atlassian Jira
(v8.20.7#820007)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org
For additional commands, e-mail: issues-h...@lucene.apache.org

Reply via email to