[
https://issues.apache.org/jira/browse/HBASE-2376?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13501669#comment-13501669
]
Pritam Damania commented on HBASE-2376:
---------------------------------------
I don't think those two JIRAs give us that flexibility. For example if TTL is 5
days and max versions is 3. If we want to support a query that gives us a view
upto 7 days in the past, then we need to retain versions upto 7 + 5 days
(effective TTL for compactions and flushes is 12 days and not 5) and we need to
retain a maximum of 3 versions before 7 days so that if we do a query for data
on 7 days in the past, we have 3 versions to surface for that query if present.
The basic idea is if we support queries in the past upto 'x' days, the
compactions and flushes should be behaving as if they were happening 'x days'
in the past.
Simply retaining deletes or retaining just one version is not sufficient.
> Add special SnapshotScanner which presents view of all data at some time in
> the past
> ------------------------------------------------------------------------------------
>
> Key: HBASE-2376
> URL: https://issues.apache.org/jira/browse/HBASE-2376
> Project: HBase
> Issue Type: New Feature
> Components: Client, regionserver
> Affects Versions: 0.20.3
> Reporter: Jonathan Gray
> Assignee: Pritam Damania
>
> In order to support a particular kind of database "snapshot" feature which
> doesn't require copying data, we came up with the idea for a special
> SnapshotScanner that would present a view of your data at some point in the
> past. The primary use case for this would be to be able to recover
> particular data/rows (but not all data, like a global rollback) should they
> have somehow been messed up (application fault, application bug, user error,
> etc.).
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
