dwm_dws_cbsjbz 小表，dwm_sap_zsdt066大表 SELECT ZYEAR,ZMONTH,ZZCPXLT,SUM(VVD02) VVD02 FROM( select a.ZYEAR, a.ZMONTH, a.KAUFN, a.KDPOS, a.MATNR, a.AUART, a.VVD02, c.ZZCPXLT from dwm_dws_cbsjbz a inner join dwm_sap_zsdt066 c on a.KAUFN = c.VBELN and a.KDPOS = c.POSNR where a.AUART = 'OR1' AND a.ZYEAR = '2023' and a.ZMONTH = '04' ) AS SFDF GROUP BY ZYEAR,ZMONTH,ZZCPXLT 优化这个语句

这个语句的优化可以从以下几个方面入手：

1. 添加索引：在dwm_dws_cbsjbz表的KAUFN和KDPOS列上添加联合索引，以及在dwm_sap_zsdt066表的VBELN和POSNR列上添加联合索引，可以提高连接查询的效率。

2. 使用子查询：将连接查询的结果作为子查询，避免了大表和小表的直接连接，减少了计算量。

优化后的SQL语句如下：

SELECT ZYEAR, ZMONTH, ZZCPXLT, SUM(VVD02) VVD02
FROM(
    SELECT a.ZYEAR, a.ZMONTH, a.VVD02, c.ZZCPXLT
    FROM dwm_dws_cbsjbz a
    INNER JOIN (
        SELECT VBELN, POSNR, ZZCPXLT
        FROM dwm_sap_zsdt066
        WHERE VBELN IN (
            SELECT KAUFN
            FROM dwm_dws_cbsjbz
            WHERE AUART = 'OR1' AND ZYEAR = '2023' AND ZMONTH = '04'
        )
    ) c ON a.KAUFN = c.VBELN AND a.KDPOS = c.POSNR
    WHERE a.AUART = 'OR1' AND a.ZYEAR = '2023' AND a.ZMONTH = '04'
) AS SFDF
GROUP BY ZYEAR, ZMONTH, ZZCPXLT;

以上是一种可能的优化方式，具体实现还需要根据你的实际情况进行调整。