File system stage

Database system stage

Manual management stage-Features: (1) Data is not saved; (2) application management data; (3) The data is not * * *; (4) the data is not independent

File system stage-Features: (1) Data can be saved for a long time; (2) Data is managed by the file system; (3) The data is poor and redundant; (4) poor data independence

Database system stage-features: (1) data structure; (2) The data * * * is interesting, low in redundancy and easy to expand; (3) High data independence; (4) The data is managed and controlled by the database management system.