import { DataType } from './expression.js';
export declare enum UnionType {
    All = "all",
    Distinct = "distinct"
}
export type VirtualSource = Array<VirtualSourceEntry>;
export interface VirtualSourceEntry {
    sourceId: string;
    unionType: UnionType;
    mappings: Array<VirtualSourceMapping>;
}
export interface VirtualSourceMapping {
    name: string;
    alias: string;
    dataType?: DataType;
}
export interface VirtualSources {
    [virtualSourceId: string]: VirtualSource;
}