+$dbh->do('TRUNCATE ratings');
+$dbh->do('COPY ratings ( id, rating, rating_stddev ) FROM STDIN');
+$dbh->pg_putcopydata(join("\n", @ratings));
+$dbh->pg_putcopyend();
+
+$dbh->do('CREATE TABLE new_covariance ( player1 smallint NOT NULL, player2 smallint NOT NULL, cov float NOT NULL )');
+$dbh->do('COPY new_covariance ( player1, player2, cov ) FROM STDIN');
+$dbh->pg_putcopydata(join("\n", @covariances));
+$dbh->pg_putcopyend();
+$dbh->do('ALTER TABLE new_covariance ADD PRIMARY KEY ( player1, player2 );');
+$dbh->do('DROP TABLE IF EXISTS covariance');
+$dbh->do('ALTER TABLE new_covariance RENAME TO covariance');
+