Table
Related Doc:
package algebra
Return all of the child nodes of this operator
Get the names of the columns produced by this operator.
Return all expression objects that appear in this node
Return a new instance of the same object, but with the children replaced with the provided list.
Replace all of the expressions in this operator.
Perform a recursive rewrite.
Perform a recursive rewrite. The following pattern is pretty common throughout Mimir: def replaceFooWithBar(e:Expression): Expression = e match { case Foo(a, b, c, ...) => Bar(a, b, c, ...) case _ => e.recur(replaceFooWithBar(_)) } Note how specific rewrites are applied to specific patterns in the tree, and recur is used to ignore/descend through every other class of object
Apply a method to recursively rewrite all of the Expressions in this object.
Apply a method to recursively rewrite all of the Expressions in this object.
Return Self.
Return Self.
This mainly exists in support of OperatorConstructors
Convert the operator into a string.
The starting point for stringification is to have no indentation
The starting point for stringification is to have no indentation
A base relation (Table).
Note that schema information is required to make Typechecking self-contained and database-independent
Metadata columns are special implicit attributes used by many database backends. They are specified as follows: (output, input, type) Where: output: The name that the implicit attribute will be referenced by in the output relation input: An expression to extract the implicit attribute type: The type of the implicit attribute. For example: ("MIMIR_ROWID", Var("ROWID"), Type.TRowId()) will extract SQL's implicit ROWID attribute into the new column "MIMIR_ROWID" with the rowid type.