如何加快ACCESS多表查询的速度

由于工作需要，我要在几个表来联合查询，得出结果，但是我写出来的语句查询速度非常慢，汗。不知道哪位可以指点一下？其中一个SQL语句如下：
SELECT CELTCHFP.EXCHID,CELTCHFP.DATE,CELTCHFP.PERIOD,SUM(CELTCHFP.TFCONGPGSM)/(SUM(RANDOMACC.CNROCNT+RANDOMACC.RAACCFA)+0.0000001)*SUM(CLTCH.TCASSALL)/(SUM(CLTCH.TASSALL)+0.0000001) as Wireless_Accessibility FROM CELTCHFP,RANDOMACC,CLTCH WHERE CELTCHFP.EXCHID = RANDOMACC.EXCHID AND CELTCHFP.DATE = RANDOMACC.DATE AND CELTCHFP.PERIOD = RANDOMACC.PERIOD AND CELTCHFP.EXCHID = CLTCH.EXCHID AND CELTCHFP.DATE = CLTCH.DATE AND CELTCHFP.PERIOD = CLTCH.PERIOD GROUP BY CELTCHFP.EXCHID,CELTCHFP.DATE,CELTCHFP.PERIOD

附件是ACCESS数据库。顺便问一下，这个速度跟数据库格式相关吗？

通常都是创建索引