DELETE falta_histo_mat.* FROM falta_histo_mat, periodo  p 
				WHERE cod_mat=10 AND tip_fal='t' AND id_alu in(1004711174,1004711174,1004711174) AND (p.id_peri=3 AND fec_fal>=  p.fec_ini and fec_fal<=fec_cor_tot)  