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https://issues.apache.org/jira/browse/PHOENIX-4999?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16670841#comment-16670841
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Karan Mehta commented on PHOENIX-4999:
--------------------------------------
[~Bin Shi]
{quote}Before any tenant user start to use stats like "EXPLAN SELECT COUNT(*)
...", the user should have updated statistics with tenant specific connection
at least once, and most likely our system has already run "UPDATE STATISTICS"
on table level either by sql command or by MR jobs.
{quote}
May not be the case all the time (or atleast till the time we add logic to
automatically run "UPDATE STATISTICS" at table level using a global connection,
think from some generic open source use case POV). However, its fine for now.
We will document it to that way and not try to fix things that probably don't
matter.
> Update statistics should not be allowed on tenant specific connection
> ---------------------------------------------------------------------
>
> Key: PHOENIX-4999
> URL: https://issues.apache.org/jira/browse/PHOENIX-4999
> Project: Phoenix
> Issue Type: Bug
> Reporter: Karan Mehta
> Assignee: Karan Mehta
> Priority: Major
>
> Update statistics sql would can trigger partial stats collection when ran
> using a tenant specific connection. Originally, update statistics internally
> runs scans on all the regions of table. TenantId field bounds the scans on
> startKey and endKey in tenant specific connection, which can cause stats to
> run only on specific regions and result in partial stats collection.
> Since the view data and table data reside in the same physical HBase table,
> it doesn't make sense to allow users to run stats for specific tenants as
> tenants may span across regions. The issue was first identified in
> PHOENIX-4333.
> The patch however doesn't fully stop the SQL from running. Multiple
> approaches can be taken here.
> # Unset the tenantId on the connection before update statistics is run and
> reset it back later. This can be tricky and bad to implement since tenantId
> is essentially a final field on PhoenixConnection.
> # As [~tdsilva] pointed out, we can throw an UnsupportedOperationException()
> whenever user tries to update statistics on tenant specific connection.
> The second option seems straightforward to implement and can prevent
> accidental usage of this sql.
> [~Bin Shi] [~sukumaddineni] Any thoughts here?
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