Easy understanding of the physical structure of Oracle databases

(1) data files

Each Oracle database has one or more physical data files ). A database data file contains all the database data. Data in logical database structures (such as tables and indexes) is physically stored in database data files. Data Files have the following features:

A data file is only associated with one database.

Once created, the data file size cannot be changed

A tablespace (logical unit of database storage) is composed of one or more data files.

The data in the data file can be read and stored in the Oracle storage zone as needed. For example, if you want to access some data in a table in the database, if the request information is not in the memory storage area of the database, it is read from the corresponding data file and stored in the memory. When you modify and insert new data, you do not need to write the data file immediately. To reduce the total number of disk outputs and improve performance, data is stored in the memory. Then, the Oracle background process DBWR decides how to write data to the corresponding data file.

1 2 3 Next Page

[Content navigation]
Page 1: Data Files	Page 1: Log Files
Page 1: Control File