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https://issues.apache.org/jira/browse/PHOENIX-6888?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Kadir Ozdemir reassigned PHOENIX-6888:
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    Assignee: Kadir Ozdemir

> Fixing TTL and Max Lookback Issues for Phoenix Tables
> -----------------------------------------------------
>
>                 Key: PHOENIX-6888
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-6888
>             Project: Phoenix
>          Issue Type: Bug
>    Affects Versions: 5.1.3
>            Reporter: Kadir Ozdemir
>            Assignee: Kadir Ozdemir
>            Priority: Major
>
> In HBase, the unit of data is a cell and data retention rules are executed at 
> the cell level. These rules are defined at the column family level. Phoenix 
> leverages the data retention features of HBase and exposes them to its users 
> to provide its TTL feature at the table level. However, these rules (since 
> they are defined at the cell level instead of the row level) results in 
> partial row retention that in turn creates data integrity issues at the 
> Phoenix level. 
> Similarly, Phoenix’s max lookback feature leverages HBase deleted data 
> retention capabilities to preserve deleted cells within a configurable max 
> lookback. This requires two data retention windows, max lookback and TTL. One 
> end of these windows is the current time and the end is a moment in the past 
> (i.e., current time minus the window size). Typically, the max lookback 
> window is shorter than the TTL window. In the max lookback window, we would 
> like to preserve the complete history of mutations regardless of how many 
> cell versions these mutations generated. In the remaining TTL window outside 
> the max lookback, we would like to apply the data retention rules defined 
> above. However, HBase provides only one data retention window. Thus, the max 
> lookback window had to be extended to become TTL window and the max lookback 
> feature results in unwantedly retaining deleted data for the maximum of max 
> lookback and TTL periods. 
> This Jira is to fix both of these issues.



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