如题：

SELECT tc_pdg_file.tc_pdg10,ima_file.ima02,ima_file.ima021 
FROM tc_pdg_file,ima_file
WHERE ima_file.ima01 IN(
                           SELECT DISTINCT tc_pdj_file.tc_pdj01  
                           FROM (SELECT ima01,'3' tc_pdj02 FROM ima_file WHERE imaacti ='Y'
                           UNION
                           SELECT tc_pdi01 ima01,'1' tc_pdj02 FROM tc_pdi_file WHERE tc_pdiacti ='Y'
                           UNION
                           SELECT bmq01 ima01,'2' tc_pdj02 FROM bmq_file WHERE bmqacti ='Y') ima_file
                           LEFT OUTER JOIN tc_pdj_file 
                          ON tc_pdj_file.tc_pdj01 = ima_file.ima01 AND tc_pdj_file.tc_pdj02 = ima_file.tc_pdj02
                          WHERE ima01 IN (SELECT tc_pdj01 FROM tc_pdj_file 
                                WHERE tc_pdj_file.tc_pdj02 = ima_file.tc_pdj02 AND tc_pdj18 like '%${tc_pdj18}%'))
             AND
             tc_pdg_file.tc_pdg01 IN(
                             SELECT DISTINCT tc_pdj03 
                             FROM (SELECT ima01,'3' tc_pdj02 FROM ima_file WHERE imaacti  ='Y' 
                             UNION 
                             SELECT tc_pdi01 ima01,'1' tc_pdj02 FROM tc_pdi_file WHERE tc_pdiacti ='Y' 
                             UNION  
                             SELECT bmq01 ima01,'2' tc_pdj02 FROM bmq_file WHERE bmqacti  ='Y') ima_file
                             LEFT OUTER JOIN tc_pdj_file 
                             ON tc_pdj_file.tc_pdj01 = ima_file.ima01 
                             AND tc_pdj_file.tc_pdj02 = ima_file.tc_pdj02  
                             WHERE ima01 IN (SELECT tc_pdj01 FROM tc_pdj_file
                                WHERE tc_pdj_file.tc_pdj02 = ima_file.tc_pdj02 AND tc_pdj18 like '%${tc_pdj18}%' ) )

此sql有点长，该如何优化？

求教，感谢