BroadaxProof

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Dispatcher Pattern (the resolving for Expression problem of Visitor pattern by Java).

Introduction Some software engineers considers that Visitor Pattern is the most difficult in design pattern. I got understood Visitor Pattern on beginning of May 2018. The understanding is as follow: Visitor Pattern is used when we want to…

Fertile Forest Model (6/n) To Find Nodes (Kinships)

To Find Nodes (Kinships) I am going to express query finding kinship nodes by the following tree structure data. [A], [B], ... indicated in figure means nodes. DEPTH| 0 | [A]--+-----------+ | | | 1 | [B]--+---+ [C]--+---+ | | | | | 2 | [D]…

Fertile Forest Model (5/n) To Find Nodes (Descendants)

To Find Nodes (Descendants) I am going to express query finding subtree nodes by the following tree structure data. [A], [B], … indicated in figure means nodes. DEPTH| 0 | [A]--+-----------+ | | | 1 | [B]--+---+ [C]--+---+ | | | | | 2 | [D…

Fertile Forest Model (4/n) To Find Nodes (Ancestors)

To Find Nodes (Ancestors) I am going to express query finding ancestor nodes by the following tree structure data. [A], [B], ... indicated in figure means nodes. DEPTH| 0 | [A]--+-----------+ | | | 1 | [B]--+---+ [C]--+---+ | | | | | 2 | […

Fertile Forest Model (3/n) Model Design

I am going to write core design of Fertile Forest Model. This content is was reprinted with permission from the official site of the Fertile Forest Model. Model Design FF model is designed by new idea. Matrix Of Hierarchical Structure I am…

Fertile Forest Model (2/n) Hierarchical Data in a RDB [2]

Additional Columns Conventional database engineers had studied four models for solving the problem to store hierarchical data in a database. They are: Adjacency List Model Path Enumeration Model Nested Set Model Nested Intervals Model Clos…

Fertile Forest Model (1/n) Hierarchical Data in a RDB [1]

Roles Of Model The role of the model to store hierarchical data in RDB are summarized in two paragraphs as: To store the hierarchical data in RDB table. To write the query to find the relevant nodes efficiently for any nodes. (1) To Store …

Fertile Forest Model (The 5th Model for Storing Hierarchical Data in a RDB)

Hierarchical Data in a Relational Database DB engineers around the world had been studying the four models for clearing the problem. These are: Adjacency List Model Path Enumeration Model Nested Set Model Neested Intervals Model Closure Ta…