import { DatasourceService } from '../../datasource.service';
import { QueryResult } from '../query-result';
import { QueryRunnerInterface } from '../query-runner.interface';
import { PostgresConnectionDriver } from './postgres-connection.driver';
export declare class PostgresQueryRunner implements QueryRunnerInterface {
    driver: PostgresConnectionDriver;
    readonly connection: DatasourceService;
    isReleased: boolean;
    isTransactionActive: boolean;
    /**
     * Special callback provided by a driver used to release a created connection.
     */
    protected releaseCallback?: (err: any) => void;
    /**
     * Real database connection from a connection pool used to perform queries.
     */
    protected databaseConnection: any;
    /**
     * Promise used to obtain a database connection from a pool for a first time.
     */
    protected databaseConnectionPromise: Promise<any> | undefined;
    constructor(driver: PostgresConnectionDriver);
    connect(): Promise<any>;
    query(query: string, parameters?: Array<unknown>): Promise<QueryResult>;
    release(): Promise<void>;
    private releasePostgresConnection;
}
