ci session database table for postgresql

CREATE TABLE  ci_sessions (
    session_id varchar(40) DEFAULT '0' NOT NULL,
    ip_address varchar(45) DEFAULT '0' NOT NULL,
    user_agent varchar(120) NOT NULL,
    last_activity bigint DEFAULT 0 NOT NULL,
    user_data text NOT NULL,
    PRIMARY KEY (session_id)
);

CREATE INDEX last_activity_idx ON ci_sessions(last_activity);