1)确保正确设置了索引(在要连接它们的列上).
2)您也可以尝试使用临时表.

此处 [ ^ ].
如果您在互联网上搜索，则应该能够找到其他技巧/文章，以帮助您优化查询.

1) Make sure you have your indexes setup properly (on the columns you are joining them on).
2) You could also try using a temporary table.

Some more tips here[^].
If you search on the internet, you should be able to find other tips / articles which can help you optimize your query.