Kadir Ozdemir created PHOENIX-6888:
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             Summary: 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


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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