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https://issues.apache.org/jira/browse/HBASE-23678?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Nick Dimiduk updated HBASE-23678:
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    Fix Version/s:     (was: 2.4.0)

> Literate builder API for version management in schema
> -----------------------------------------------------
>
>                 Key: HBASE-23678
>                 URL: https://issues.apache.org/jira/browse/HBASE-23678
>             Project: HBase
>          Issue Type: Improvement
>            Reporter: Andrew Kyle Purtell
>            Assignee: Viraj Jasani
>            Priority: Major
>             Fix For: 3.0.0-alpha-1, 2.3.0, 1.7.0
>
>
> Lars designed the combination of VERSIONS, TTL, MIN_VERSIONS, and 
> KEEP_DELETED_CELLS with a maximum of flexibility. There is a lot of nuance 
> regarding their usage. Almost all combinations of these four settings make 
> sense for some use cases (exceptions are MIN_VERSIONS > 0 without TTL, and 
> KEEP_DELETED_CELLS=TTL without TTL). There should be a way to make the 
> behavior with TTL easier to conceive when creating the schema. This could 
> take the form of a literate builder API for ColumnDescriptor or an extension 
> to an existing one. 
> Let me give you a motivating example: We may want to retain all versions for 
> a given TTL, and then only a specific number of versions after that interval 
> elapses. This can be achieved with VERSIONS=INT_MAX, 
> TTL=_retention_interval_, KEEP_DELETED_CELLS=TTL, MIN_VERSIONS=_num_versions_ 
> . This is not intuitive though because VERSIONS has been used to specify the 
> number of versions to retain (_num_versions_ in this example) since HBase 
> version 0.1, so this is going to be a source of confusion - I've seen it in 
> practice. 
> A literate builder API, by way of the way we design its method names, could 
> let a user describe more or less in speaking language how they want version 
> retention to work, and internally the builder API could set the low level 
> schema attributes. 



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