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


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Re: [jira] [Commented] (ACCUMULO-227) Improve in memory map counts to provide cell level uniqueness for repeated columns in mutation
Aaron Cordova 2011-12-22, 22:17
The reason for 'all but one' is to adhere to the concept of a map, and by 'arbitrarily' I mean, whatever way incurs the least processing cost.

On Dec 22, 2011, at 5:09 PM, Keith Turner wrote:

> This still does not address the issue of separate mutations inserting
> the exact same key.  Also timestamps are only set on the keys in a
> mutation if the user does not set them.
>
> So if a table comes to have multiple keys that are exactly the same,
> what do you propose?  That we drop them?  Which one will you drop?
> One nice thing about Accumulo is that if you wish to have this
> behavior, you can very easily write an iterator to do it.  I think you
> are proposing that we configure an iterator to do this by default?
>
> I think if the user is inserting things with exact same key and
> expecting it to behave like a treemap (honor order of arrival), then
> it never will.  Even if we drop duplicate keys, we will not achieve
> the map behavior you described.