通过多个线程从数据库加载数据的最佳方法是什么

Question

I have some data in database in parent child relation, where my table is actually representing a forest of tree data structure.

And the table structure is like:

row1  parent: null
row2  parent:row1
row3  parent:row2
row4  parent:row1

Now when I am loading this data from DB to my data structure by JDBC, then what I am doing now is:

1. load all row where parent is null [load all the root of trees]
2. Then for each child of each root load the child in a recursive manner.
3. But here all the trees are loaded one by one.

What I want to do, spawn a thread for each tree, thus all the trees can be loaded concurrently. Any framework I can use with JDBC for the same, or any suggestion, help please.

Answer 1

您可以使用休眠框架在任何数据库中操作（创建，删除，插入，更新..）数据，这对于数据操作非常灵活

Answer 2

Whilst this does not directly answer your exact question, I would encourage you to review your data structure. You have used the Adjacency List Model which, whist simple to implement initially, opens a whole ugly can of worms when it comes to querying.

There are other models to consider, such as Nested Set Model , for which querying of trees and sub-trees is much easier.

Both are explained well in this article: Managing Hierarchical Data in MySQL

Although the article is RDBMS vendor specific, if could easily be adjusted to suit your system.