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https://issues.apache.org/jira/browse/CALCITE-724?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14542533#comment-14542533
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Andy Grove commented on CALCITE-724:
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Good point. The first use case I am implementing is a join to the primary key
of the table so I am thinking too specifically about that rather than the
general case.
`SELECT * FROM orders, customer WHERE orders.customer_id = customer.id`
> With a hash join the "key" you get from the left would have to be a single
> value
Presumably it could be multiple values in the case of a composite key e.g.
`WHERE left.a = right.a AND left.b = right.b`
Maybe this specific type of join, with correlation between simple column
expressions, is a hash join but is a specialization of a more general case?
> Add support for hash join using an index
> ----------------------------------------
>
> Key: CALCITE-724
> URL: https://issues.apache.org/jira/browse/CALCITE-724
> Project: Calcite
> Issue Type: Improvement
> Affects Versions: 1.3.0-incubating
> Reporter: Andy Grove
> Assignee: Julian Hyde
>
> I would like to implement a hash join where the left input is a stream or a
> table scan and for each incoming tuple I would like Calcite to perform an
> index-based lookup against a table to find matching tuples.
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