[jira] [Updated] (HBASE-10247) Client promises about timestamps

["Lars Hofhansl (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-10247?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Lars Hofhansl updated HBASE-10247:
----------------------------------

    Attachment: 10247.txt

*Partial* patch. Completely untested, and not even 1/3 finished. Just want to park it here. Will probably finish it tomorrow or the day after.

So far has:
* the new table attribute
* old tables are "grandfathered in" as MIXED
* new tables default to SERVER_TS
* can be set/viewed via shell

Missing:
* nothing is enforced, yet.
* transitions are not yet restricted
* no tests, yet.


> Client promises about timestamps
> --------------------------------
>
>                 Key: HBASE-10247
>                 URL: https://issues.apache.org/jira/browse/HBASE-10247
>             Project: HBase
>          Issue Type: Brainstorming
>            Reporter: Lars Hofhansl
>            Priority: Minor
>         Attachments: 10247.txt
>
>
> This is to start a discussion about timestamp promises declared per table of CF.
> For example if a client promises only monotonically increasing timestamps (or no custom set timestamps) and VERSIONS=1, we can aggressively and easily remove old versions of the same row/fam/col from the memstore before we flush, just by supplying a comparator that ignores the timestamp (i.e. two KV just differing by TS would be considered equal).
> That would increase the performance of counters significantly.



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