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https://issues.apache.org/jira/browse/PHOENIX-4964?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16646861#comment-16646861
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Lars Hofhansl commented on PHOENIX-4964:
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Brief update... The current code assume that if all columns are covered by the
index the index is the best options and in any other case the index is not a
good option. Both assumptions are not generally correct. At the very least we
should allow to override by a hint.
> ORDER BY does not use an index if the query is not fully covered
> ----------------------------------------------------------------
>
> Key: PHOENIX-4964
> URL: https://issues.apache.org/jira/browse/PHOENIX-4964
> Project: Phoenix
> Issue Type: Improvement
> Reporter: Lars Hofhansl
> Priority: Minor
>
> I just noticed that a query like
> {{SELECT <column1> FROM <table> ORDER BY <column2> LIMIT <n>}}
> Does not use an index on <column2> if it does not also include <column1>.
> That seems too limited.
> I can see the code in QueryOptimizer.addPlan that rewrites the plan only when
> there's a WHERE clause, and then only for the WHERE clause.
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