Julian Hyde created DRILL-57:
--------------------------------
Summary: 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
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.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
