ACCUMULO-4629 add exact deletes

[keith-turner]

No description provided.

[ctubbsii]

Is there a write-up of what an "exact delete" is and what the overall design of this implementation is?

[keith-turner]

Is there a write-up of what an "exact delete" is and what the overall design of this implementation is?

There is now : apache/accumulo-website#102

There is also what was on the JIRA issue.

[mikewalch]

I really like exact deletes. I think it would be a great feature to add. It just seems more useful if it was done on a per-mutation basis instead of changing the behavior of the table. It would be nice if users could choose between range and exact deletes.

If you are looking to improve performance by minimizing seeks for deletes, what about adding the option to turn off deletes for a table at creation time?

[ctubbsii]

I have similar thoughts as @mikewalch .

I think it would be sufficient to provide a per-table configuration to disable delete marker processing (can be enabled or disabled, by admin): FAIL or PROCESS.

The specific behavior when PROCESSing deletes could be directed by information stored in the value of a delete marker, and set with new putDelete APIs on mutation. (A future/follow-on change.)

We can mark this feature as experimental, because I'm not sure it is the best way to achieve the performance desired for applications which aren't expected to have delete markers. (A suggestion was made to possibly switch the order of the delete and timestamp dimensions of the key to achieve that performance.)

[keith-turner]

@mikewalch and @ctubbsii I agree with your assessments. I opened #598 based on your comments.