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Accumulo, mail # dev - Re: [jira] [Updated] (ACCUMULO-227) Improve in memory map counts to provide cell level uniqueness for repeated columns in  mutation


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Re: [jira] [Updated] (ACCUMULO-227) Improve in memory map counts to provide cell level uniqueness for repeated columns in  mutation
Aaron Cordova 2011-12-23, 22:36
Adam,

I agree with all your answers in the worksheet. I don't have strong opinions about whether the values shown should be deterministic or not.

The thing I have an issue with is the following code:

Mutation m = new Mutation(row)
m.put("cf", "cq", 5L, "1")
bw.addMutation(m)

Mutation m2 = new Mutation(row)
m.put("cf", "cq", 5L, "2")
bw.addMutation
The scanner should then only return one of "1" or "2", even when the table is configured to return all versions. This is because the user has only provided one version of one key. One can consider one as overwriting the other .. internally the server should return one and ignore the rest. I don't care if this is deterministic or not.

Aaron

On Dec 23, 2011, at 1:40 PM, Adam Fuchs (Updated) (JIRA) wrote:

>
>     [ https://issues.apache.org/jira/browse/ACCUMULO-227?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
>
> Adam Fuchs updated ACCUMULO-227:
> --------------------------------
>
>    Attachment: worksheet.tex
>                worksheet.pdf
>
> Here's a draft of a worksheet to try to solidify the discussion of fine-grained semantics related to cell-level uniqueness.
>
>> Improve in memory map counts to provide cell level uniqueness for repeated columns in  mutation
>> -----------------------------------------------------------------------------------------------
>>
>>                Key: ACCUMULO-227
>>                URL: https://issues.apache.org/jira/browse/ACCUMULO-227
>>            Project: Accumulo
>>         Issue Type: Improvement
>>         Components: tserver
>>           Reporter: John Vines
>>           Assignee: John Vines
>>            Fix For: 1.5.0
>>
>>        Attachments: worksheet.pdf, worksheet.tex
>>
>>
>> Currently for isolation we only isolate mutations. This doesn't allow mutations with identical cells within it. We should increase the mutation counts to account for each individual cell instead of each mutation.
>
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