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https://issues.apache.org/jira/browse/DRILL-57?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13676079#comment-13676079
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Jason Altekruse commented on DRILL-57:
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I have created an implementation of this operator using the code from the
JsonRecordReader to convert the records passed in the content field into
unbacked records. It looks like type inferencing is working well with that, but
we will need to develop a format for specifying types if we would like the
option to type them explicitly.
> Add a logical operator that returns a constant result, similar to VALUES
> operator in SQL
> ----------------------------------------------------------------------------------------
>
> Key: DRILL-57
> URL: https://issues.apache.org/jira/browse/DRILL-57
> Project: Apache Drill
> Issue Type: Bug
> Reporter: Julian Hyde
> Assignee: Michael Hausenblas
>
> Add a logical operator that returns a constant result. This is necessary to
> be able to create values out of thin air, if you don't know what tables exist.
> This operator is analogous to the VALUES operator in SQL. For example,
> VALUES (1, 'a'), (2, 'b'), (3, 'c')
> returns 2 rows with 3 columns and
> VALUES (1, 'a'), (2, 'b'), (3, 'c') AS t(c1, c2)
> allows you to name those columns "c1" and "c2". VALUES is useful for
> evaluating expressions that don't belong in a table, for example
> VALUES 10 + 3
> (Some databases would express this "SELECT 10 + 3". Same idea, and same
> underlying relational operator.)
> The JSON for this new operator might look like this:
> {
> op: "constant",
> content: { [
> {c1: 1, c2: "a"},
> {c1: 2, c3: ["x", "y", "z"]}
> ] }
> }
> This operator is necessary in order to implement the SQL VALUES clause.
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