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From John Lilley <john.lil...@redpoint.net>
Subject RE: Questions: history of deleted records, controlling timestamps
Date Fri, 18 Dec 2015 14:56:54 GMT
Thanks Thomas!

What I'm trying to accomplish with "a set of changes at the same timestamp" is several things.
 Basically I'm trying to implement a "versioned database" in which a set of changes to tables
are grouped into a "changeset" that we can tag with additional information:
-- Associate changes across multiple tables (I know this could be done by adding an additional
index to the tables, but using timestamp for this purpose would kill two birds with one stone)
-- Have a clear "transactionlike" event on which we can hang additional meta-data
-- Make the set of changes all appear to have happened "at the same time"
-- Hopefully, be able to undo all of the changes of a changeset.

Thanks
John

-----Original Message-----
From: Thomas D'Silva [mailto:tdsilva@salesforce.com] 
Sent: Thursday, December 17, 2015 7:56 PM
To: user@phoenix.apache.org
Subject: Re: Questions: history of deleted records, controlling timestamps

John,

If you enable KEEP_DELETED_CELLS on the underlying HBase table you will be able to see deleted
data (See http://hbase.apache.org/0.94/book/cf.keep.deleted.html ) Could you describe what
you mean by making a set of changes at the same timestamp?

Thanks,
Thomas

On Thu, Dec 17, 2015 at 4:50 PM, John Lilley <john.lilley@redpoint.net> wrote:
> Greetings,
>
>
>
> I’ve been reading about Phoenix with an eye toward implementing a 
> “versioned database” on Hadoop.  It looks pretty slick, especially the 
> ability to query at past timestamp.  But I can’t figure out what 
> happens with deleted records.  Are all versions deleted, or can I 
> still go back in time and see the versions before the delete?
>
>
>
> Also I would like to be able to make a set of changes “at the same 
> timestamp” to a get a changeset-like ability similar to a VCS.  It 
> looks like the APIs allow for setting of the effective timestamp for 
> all change operations; is that true?
>
>
>
> Thanks
>
> John Lilley
>
>
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