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Data structure only studies the logical structure and physical structure of data. Is this correct?

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2019-11-19 09:13:069399browse

Data structure only studies the logical structure and physical structure of data. Is this correct?

This view is not entirely correct. I feel that data structure mainly studies the logical relationship between data and the operation of the database in non-numeric application problems. It also studies how to Data with logical relationships are stored in the computer in a certain storage method. Analyze the logical relationship between data and determine the storage structure of data in the computer (Recommended learning: web front-end video tutorial)

Data structure is the way that computers store and organize data . A data structure refers to a collection of data elements that have one or more specific relationships with each other. Often, carefully selected data structures can lead to higher operating or storage efficiency. Data structures are often related to efficient retrieval algorithms and indexing techniques.

Research object

Logical structure of data

refers to the data structure that reflects the logical relationship between data elements, where The logical relationship refers to the context relationship between data elements, regardless of their storage location in the computer. The logical structure includes:

1. Set: There is no other relationship between elements in the data structure except that they "belong to the same set";

2. Linear structure: Data structure There is a one-to-one relationship between the elements in the data structure;

3. Tree structure: There is a one-to-many relationship between the elements in the data structure;

4. Graphic structure: In the data structure There is a many-to-many relationship between the elements.

The physical structure of data

refers to the storage form of the logical structure of data in the computer storage space.

The physical structure of data is the representation of the data structure in the computer (also known as the image), which includes the in-machine representation of data elements and the in-machine representation of relationships. Since the specific implementation methods include sequence, linking, indexing, hashing, etc., a data structure can be expressed as one or more storage structures.

In-machine representation of data elements (mapping method): Data elements are represented by bit strings of binary bits (bits). This bit string is usually called a node. When a data element consists of several data items, the sub-bit string corresponding to each data item in the bit string is called the data field. Therefore, a node is an in-machine representation (or in-machine image) of a data element.

In-machine representation of relationships (mapping method): The in-machine representation of relationships between data elements can be divided into sequential images and non-sequential images. There are two commonly used storage structures: sequential storage structures and chain storage structures. .

Sequential mapping uses the relative position of elements in memory to represent the logical relationship between data elements. Non-sequential images represent logical relationships between data elements with the help of pointers that indicate the storage locations of elements.

Data storage structure

The storage form of the logical structure of data in the computer storage space is called the physical structure of the data (also called the storage structure). Generally speaking, the logical structure of a data structure can be expressed as a variety of storage structures as needed. Commonly used storage structures include sequential storage, chain storage, index storage, hash storage, etc.

The characteristics of the data storage structure are: the relative position of the elements in the memory is used to represent the logical relationship between data elements; the characteristics of non-sequential storage are: the use of pointers indicating the storage addresses of the elements to represent the relationship between data elements. logical relationship between them.

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