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https://issues.apache.org/jira/browse/IGNITE-23307?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17886901#comment-17886901
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Roman Puchkovskiy commented on IGNITE-23307:
--------------------------------------------

The patch looks good to me

> Deal with getting timestamp for compacted revision
> --------------------------------------------------
>
>                 Key: IGNITE-23307
>                 URL: https://issues.apache.org/jira/browse/IGNITE-23307
>             Project: Ignite
>          Issue Type: Improvement
>            Reporter: Kirill Tkalenko
>            Assignee: Kirill Tkalenko
>            Priority: Major
>              Labels: ignite-3
>
> We need to figure out what to do with methods 
> *org.apache.ignite.internal.metastorage.server.KeyValueStorage#timestampByRevision*
>  and 
> *org.apache.ignite.internal.metastorage.server.KeyValueStorage#revisionByTimestamp*
>  after compaction.
> Let's look at an example, let's say we have keys with the following revisions:
> # "foo" [1, 3, 5]
> # "bar" [1]
> # "one" [2]
> Let's say there was a compaction on revision 6, and now the key has the 
> following revisions:
> # "foo" [5]
> # "bar" [1]
> # "one" [2]
> Options like the above methods should work:
> * Ignoring key revisions:
> # *KeyValueStorage#timestampByRevision* - will throw *CompactedException* 
> when requesting a revision less than or equal to 6.
> # *KeyValueStorage#revisionByTimestamp* - will return *-1* if the time is 
> less than the time of the 7th storage revision.
> * Taking into account key revisions:
> # *KeyValueStorage#timestampByRevision* - will throw *CompactedException* 
> only when there are no keys with a compacted revision. From the example above 
> it will throw an exception for revisions 3, 4 and return a value for the rest.
> # *KeyValueStorage#revisionByTimestamp* - will return the timestamp it finds.
> I am for option "Ignoring key revisions", it looks simple and clear.
> {color:#DE350B}Update:{color}
> After thinking and discussing with colleagues, we decided to add a timestamp 
> to *org.apache.ignite.internal.metastorage.Entry* (IGNITE-23348) and it will 
> throw *CompactedException* when invoking methods 
> *KeyValueStorage#timestampByRevision* and 
> *KeyValueStorage#revisionByTimestamp* if we will find out that the revision 
> has already been compacted.



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