Method union

datafusion/expr/src/logical_plan/builder.rs:868–870

Apply a union, preserving duplicate rows

(self, plan: LogicalPlan)

    /// Apply a union, preserving duplicate rows
    pub fn union(self, plan: LogicalPlan) -> Result<Self> {
        union(Arc::unwrap_or_clone(self.plan), plan).map(Self::new)
    }

    /// Apply a union by name, preserving duplicate rows
    pub fn union_by_name(self, plan: LogicalPlan) -> Result<Self> {