New Join Reorder

[EmmyMiao87]

background

The current JoinReorder algorithm mainly sorts according to the star model, and only considers the query association relationship between the table and the table.

His problem is:

1. Only applicable to user data whose data model is a star model, data of other models cannot be sorted.

2. Regardless of the cost consumption of the table, it is impossible to determine the size of the join table relationship, and the real query optimization ability is weak.

3. It is not possible to avoid possible time-consuming joins such as cross joins by sorting.