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From "ramkrishna.s.vasudevan (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (PHOENIX-1296) Scan entire region when tenant-specific table is analyzed
Date Fri, 26 Sep 2014 12:18:34 GMT

    [ https://issues.apache.org/jira/browse/PHOENIX-1296?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14149084#comment-14149084
] 

ramkrishna.s.vasudevan commented on PHOENIX-1296:
-------------------------------------------------

[~giacomotaylor]
I don't think this we have to do. Consider there are two tenants that has the Tenant ID as
AZ and SZ (for example).
Assume in the tenantID1 there is an entry row1.
Now when the guideposts are formed for tenantID1 then the start row will anyway have AZ to
AZ1.
The guideposts will select [*][AZ], [AZ][AZrow1],[AZrow1][*].
This seems like we are scanning the entire region but as the start row is anyway AZ to AZ1
our scan would anyway get restricted within that range.  Do you feel we still need this?

> Scan entire region when tenant-specific table is analyzed
> ---------------------------------------------------------
>
>                 Key: PHOENIX-1296
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-1296
>             Project: Phoenix
>          Issue Type: Sub-task
>            Reporter: James Taylor
>            Assignee: ramkrishna.s.vasudevan
>
> Based on the issue you've uncovered (that stats must be updated completely for a region),
there's a bit of follow on work needed if an ANALYZE is done on a tenant-specific table. This
case will be optimized to only scan and analyze the current tenant's data, however we have
to make sure that the entire region(s) containing that tenant's data is scanned (or we'll
end up replacing the stats for that region with just the one we calculated for that tenant).
> We should be able to do that based on ScanUtil.isAnalyzeTable(scan) being true in DefaultParallelIteratorRegionSplitter
and/or ParallelIterators.



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