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https://issues.apache.org/jira/browse/FLINK-1005?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Robert Metzger updated FLINK-1005:
----------------------------------
    Fix Version/s:     (was: 0.7.0-incubating)
                   0.8-incubating

> Add different mutable-object modes to runtime
> ---------------------------------------------
>
>                 Key: FLINK-1005
>                 URL: https://issues.apache.org/jira/browse/FLINK-1005
>             Project: Flink
>          Issue Type: Improvement
>          Components: Local Runtime
>    Affects Versions: 0.6-incubating
>            Reporter: Stephan Ewen
>            Assignee: Stephan Ewen
>             Fix For: 0.8-incubating
>
>
> Currently, the runtime works strictly with mutable objects. That means that 
> as few objects as possible (typically one or two) are reused for the data 
> records all the time. Objects are cloned/restored, though, at various places 
> to ensure that the contents is fresh at every call.
> The rational behind this was to reduce pressure on the garbage collector. In 
> fact, you can run programs where no garbage collection happens (if the UDFs 
> are written to reuse objects as well).
> It can, however, lead to bugs in not-carefully written user code.
> I propose to add two modes to the runtime:
>   - No-object-reuse (default) mode. New objects for every record. Safe but 
> potentially slower.
>   - Object-reusing mode - All objects are reused, without backup copies.. The 
> UDFs must be careful to not keep any objects as state or not to modify the 
> objects,



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