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From "Tupshin Harper (JIRA)" <j...@apache.org>
Subject [jira] [Comment Edited] (CASSANDRA-7056) Add RAMP transactions
Date Wed, 25 Jun 2014 12:26:24 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-7056?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14043367#comment-14043367
] 

Tupshin Harper edited comment on CASSANDRA-7056 at 6/25/14 12:25 PM:
---------------------------------------------------------------------

Cross table consistent reads are of fundamental importance. 

Once you allow that they are useful for consistent index reads, then you have admitted that
they are useful for for direct consumption by users, since we are constantly advising them
to build their own index solutions since 2i are horrendously weak.  That pressure will be
only slightly reduced with global indexes. 

Even separate from custom (client-side) 2i implementations, having all or nothing read visibility
of writes spanning tables captures fundamental business logic that is either painfully worked
around today, or else is glossed over as statistically unlikely (depending on the r/w patterns)
and the race conditions duly ignored. 

It would be a tragic mistake to ignore the benefits of the gains in correctness that can be
achieved.


was (Author: tupshin):
Cross table consistent reads are of fundamental importance. 

Once you allow that they are useful for consistent index reads, then you have admitted that
they are useful for for direction consumption by users, since we are constantly advising them
to build their own index solutions since 2i are horrendously weak.  That pressure will be
only slightly reduced with global indexes. 

Even separate from custom (client-side) 2i implementations, having all or nothing read visibility
of writes spanning tables captures fundamental business logic that is either painfully worked
around today, or else is glossed over as statistically unlikely (depending on the r/w patterns)
and the race conditions duly ignored. 

It would be a tragic mistake to ignore the benefits of the gains in correctness that can be
achieved.

> Add RAMP transactions
> ---------------------
>
>                 Key: CASSANDRA-7056
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-7056
>             Project: Cassandra
>          Issue Type: Wish
>          Components: Core
>            Reporter: Tupshin Harper
>            Priority: Minor
>
> We should take a look at [RAMP|http://www.bailis.org/blog/scalable-atomic-visibility-with-ramp-transactions/]
transactions, and figure out if they can be used to provide more efficient LWT (or LWT-like)
operations.



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