[
https://issues.apache.org/jira/browse/HBASE-10247?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14001637#comment-14001637
]
Andrew Purtell commented on HBASE-10247:
----------------------------------------
bq. * can you switch states? From SERVER_ONLY to CLIENT_OK, or CLIENT_MONOTONIC
is OK. From CLIENT_MONOTONIC to CLIENT_OK is also OK.
I like the idea of adding a table attribute that switches on assumptions about
semantic guarantees. I also like the idea of well defined states and helpful
rejection of invalid transitions.
bq. Mixed mode, or something like that to support existing tables.
What does mixed mode mean in terms of allowing the server side to make
assumptions about timestamps? Intuitively the answer is none. So this would be
captured by the absence of a table attribute?
The notion of 'states' here and 'modes' at
https://issues.apache.org/jira/browse/HBASE-9905?focusedCommentId=13815414&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13815414
seem really close.
> 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
>
> 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.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
