есть запрос

SELECT DISTINCT MAIN1.code AS Codm1, MAIN.code AS CODP, vers.code AS codever, vers.vers, MAIN.MARKA, MAIN.fold, MAIN.COMMENT, 
vers.mat1, MAIN1.prod, MAIN1.lev, MAIN1.own, MAIN1.qt, 
IIf(Exists (select tprcs.code from tprcs where tprcs.codever=vers.code),True,False) AS tp, 
IIf(Exists (select spztmp.code from spztmp where spztmp.codm1=main1.code),True,False) AS pn  
FROM tprcs RIGHT JOIN ((MAIN INNER JOIN vers 
ON MAIN.CODE = vers.codem) INNER JOIN MAIN1 
ON vers.code = MAIN1.codever) 
ON tprcs.codever = vers.code  WHERE (((MAIN1.sernn) = " & Me!serc & ")) 
ORDER BY MAIN1.lev, MAIN.MARKA, MAIN1.code;

Выполняется секунд 15-20
Можно ли его оптимизировать?

https://www.sql.ru/forum/1317450/optimizaciya-zaprosa