/**
 * Database Import — pg-backed data access for the copy executor.
 *
 * Thin wrappers around `pg` implementing the SourceReader / TargetWriter
 * interfaces from copy-data.ts. `pg` is imported lazily and SSL is enabled by
 * default (Supabase requires it). Integration-level: covered by manual/E2E
 * runs, while the copy logic itself is unit-tested with fakes.
 */
import { SourceReader, TargetWriter } from "./copy-data";
/** Reads rows from the source database (read-only). */
export declare class PgSourceReader implements SourceReader {
    private readonly client;
    private readonly schema;
    private constructor();
    static connect(connectionString: string, schema: string): Promise<PgSourceReader>;
    totalRows(table: string): Promise<number>;
    readBatch(table: string, columns: string[], orderBy: string | null, offset: number, limit: number): Promise<unknown[][]>;
    close(): Promise<void>;
}
/** Writes rows into the target database within a single transaction. */
export declare class PgTargetWriter implements TargetWriter {
    private readonly client;
    private readonly schema;
    private constructor();
    static connect(connectionString: string, schema: string): Promise<PgTargetWriter>;
    rowCount(table: string): Promise<number>;
    insertBatch(table: string, columns: string[], rows: unknown[][]): Promise<void>;
    resetSequence(table: string, column: string): Promise<void>;
    begin(): Promise<void>;
    commit(): Promise<void>;
    rollback(): Promise<void>;
    close(): Promise<void>;
}