I have an issue with running a slow left Join query, on mixed backends. The Exist table is on a SQL 2014 server, and the New table is on a Access 2010 backend. Both tables contains around 250.000 records. Querying them each goes fine, but doing a left join, just seems to hang Access. Theres indexes on all the fields involved in the join.
FROM tbl_SALES_NEW LEFT JOIN tbl_SALES_EXIST ON (tbl_SALES_NEW.CustomerID = tbl_SALES_EXIST.CustomerID) AND (tbl_SALES_NEW.ArticleID = tbl_SALES_EXIST.ArticleID)
WHERE (((tbl_SALES_EXIST.CustomerID) Is Null) AND ((tbl_SALES_EXIST.ArticleID) Is Null));