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https://issues.apache.org/jira/browse/PHOENIX-2909?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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James Taylor updated PHOENIX-2909:
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Summary: Surface checkAndPut through UPDATE statement (was: Surface
checkAndPut through UPDATE support)
> Surface checkAndPut through UPDATE statement
> --------------------------------------------
>
> Key: PHOENIX-2909
> URL: https://issues.apache.org/jira/browse/PHOENIX-2909
> Project: Phoenix
> Issue Type: Bug
> Reporter: James Taylor
>
> We can surface atomic checkAndPut like functionality through support of the
> SQL UPSERT statement.
> For example, the following could use do a get under row lock to perform the
> row update atomically
> {code}
> UPDATE my_table SET counter=coalesce(counter,0) + 1 FROM my_table;
> {code}
> To force prior MVCC transactions to complete (making it serializable as an
> Increment is), we'd have code like this:
> {code}
> mvcc = region.getMVCC();
> mvcc.completeMemstoreInsert(mvcc.beginMemstoreInsert());
> {code}
> By users setting auto commit to true and issuing an UPDATE statement over a
> non transactional table, they'd get a way for row updates to be atomic. This
> would work especially well to support counters.
> Note that the coalesce call above handles the case where counter is null.
> This could be made prettier with support for the DEFAULT clause at CREATE
> TABLE time (PHOENIX-476).
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