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https://issues.apache.org/jira/browse/PHOENIX-5090?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16734874#comment-16734874
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Yonatan Gottesman commented on PHOENIX-5090:
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In omid transaction are in column resolution so every column has its own shadow
cell. the client stores all *cells* that are changed not rows. Also there is a
mode in omid that you can use in order not to keep track of changed cells and
it wont do conflict resolution. Its used in phoenix whenÂ
PTable:isImmutableRows() is true.
> Discuss: Allow transactional writes without buffering the entire transaction
> on the client.
> -------------------------------------------------------------------------------------------
>
> Key: PHOENIX-5090
> URL: https://issues.apache.org/jira/browse/PHOENIX-5090
> Project: Phoenix
> Issue Type: Wish
> Reporter: Lars Hofhansl
> Priority: Major
>
> Currently it is not possible execute transactions in Phoenix that are too
> large to be buffered entirely on the client.
> Both Tephra and Omid support writing uncommitted data to HBase immediately
> and at full speed. The client still needs to keep tracks of the rows changes
> for:
> # Conflict detection
> # (for Omid) writing the shadow cells
> I'd like to do some brainstorming here.
> * It should *always* be enough to only hold on to the changed rows (and
> columns?) only for _conflict resolution_ and free the rest from the client as
> soon as the uncommitted data is written to HBase.
> * For the shadows cells we need only keep the rows changed, right?
> * There are situations where we can avoid the client site buffering entirely
> (perhaps only for Tephra) when we declare a table or upsert not to
> participate in conflict resolution.
> [~tdsilva], [~ohads], [~yonigo], [~jamestaylor], [~vincentpoon], more, better
> ideas?
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