What is the relational database storage mode?

Relational database storage mode is a database storage mode based on relational model, which manages data through relational database management system (RDBMS). Relational model is the most popular data model in the field of commercial database at present, and its basic idea is to represent entities and their relationships with two-dimensional tables. Each column in the two-dimensional table corresponds to the attribute of an entity, and the corresponding attribute value is given. Each row forms a tuple, or triple, composed of multiple attributes, corresponding to a specific entity.

Using relational database storage mode, its main features are:

(1) relation structure is flexible, which can meet all the query requirements formed by Boolean logic operation and mathematical operation rules.

(2) Relational data can also search, combine and compare different types of data, and it is also convenient to add and delete data.

(3) Its disadvantage is that many operations require to find data that meet specific relational conditions in the file in order. If the database is large, this search process will take a lot of time.

In the early construction of land information system, relational database is generally used to store management attribute data, while the management of spatial data is mostly organized and managed by files. One of the main reasons is that the relational database has insufficient expressive ability for geospatial data; Second, some data models and data files in GIS software are closely combined.

With the development of database technology and the wide application of geographic information system technology, the spatial data management technology based on relational object database is becoming more and more mature, and a commercial software system with unified storage of spatial data and attribute data has emerged. For example, Oracle Spatial, an Oracle database system product, supports the storage and management of spatial data, and uses Esri's Arc SDE to manage spatial data.