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https://issues.apache.org/jira/browse/CALCITE-771?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16871020#comment-16871020
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Danny Chan commented on CALCITE-771:
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Thanks, [~donnyzone], i have left some review comments.
> Use materialization for scan-project-sort query
> -----------------------------------------------
>
> Key: CALCITE-771
> URL: https://issues.apache.org/jira/browse/CALCITE-771
> Project: Calcite
> Issue Type: Bug
> Reporter: Julian Hyde
> Priority: Major
> Labels: pull-request-available
> Time Spent: 0.5h
> Remaining Estimate: 0h
>
> If a materialization is defined for scan-project-sort over another table,
> then scan-project and scan-project-sort queries should be able to use it.
> For example, given the following schema (in pseudo-DDL):
> {code}
> CREATE TABLE Emp (empid, deptno, gender);
> CREATE MATERIALIZATION I_Emp_Deptno AS
> SELECT deptno, empid FROM Emp ORDER BY deptno;
> {code}
> Calcite should rewrite the query
> {code}SELECT deptno FROM Emp ORDER BY deptno{code}
> to
> {code}
> Project(deptno)
> TableScan(table=[I_Emp_Deptno])
> {code}
> Note that no sort is necessary.
> This rewrite is important for using secondary indexes.
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