[ 
https://issues.apache.org/jira/browse/LUCENE-8198?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16394667#comment-16394667
 ] 

Robert Muir commented on LUCENE-8198:
-------------------------------------

Well the overhead should be... 1 bit per document unless something is wrong? So 
a user would add something like a "soft live" field and then just update it to 
a 0. I think its easy to filter on such fields in searches already.

 

There are some advantages of doing it this way far as performance goes I think. 
For example, take the extreme case where a user never "hard"-deletes at all. 
They'd still always get bulk merge optimizations from the stored fields writer, 
etc.

> Add ability to persist deletes across merges
> --------------------------------------------
>
>                 Key: LUCENE-8198
>                 URL: https://issues.apache.org/jira/browse/LUCENE-8198
>             Project: Lucene - Core
>          Issue Type: Improvement
>    Affects Versions: 7.3, master (8.0)
>            Reporter: Simon Willnauer
>            Assignee: Simon Willnauer
>            Priority: Major
>         Attachments: LUCENE-8198.patch
>
>
> This allows conditionally persist deletes on a per document basis to prevent 
> them from being merged away. This expert feature is useful to maintain 
> history of documents in the index where otherwise a duplicate storage 
> mechanism would be needed. For instance features like CouchDBs changes API 
> can be build on top of persistent deletes. While using persistent deletes has 
> a considerably small overhead at merge time or when deletes applied to fully 
> deleted segments, there is no impact if persistent deletes are unused.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

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

Reply via email to