Liunx MySQL database using three paradigms, relational model design considerations, installation directory structure

Three Paradigms of database
First Paradigm
===> the attributes of each row of records, are atomic, and are not detachable until they are disassembled.
===> For example: A person's native place, can be split into, province, city, County, township, village

Second Paradigm
===> a non-primary property (non-primary key attribute) for each row of records is completely dependent on the primary property (primary key).
===> each row of data can be uniquely differentiated.
===> For example: A school teacher, his name, age, gender, birthplace. are dependent on its teacher number
===> and it teaches the subject, does not rely on his number, then need to build another table, as a relational model, to store

Third Paradigm
===> in an Entity relationship, if no non-critical fields are dependent on the function passing on either of the candidate key fields. is in accordance with the third paradigm.
===> Once you have attributes, you can rely on the primary key, and you can rely on another field. It's going to be split into two tables.
===> School number, name, gender, department, attribution College
===> department can rely on the school number, can also rely on the school of attribution. You can split the two tables into one. (School number, name, gender) (department, School of Attribution)


Some basic requirements of relational database in relational schema design
Data redundancy in---> database is as small as possible.
---> Data does not appear to be inserted when the database performs insert work
---> Data in the database cannot be inconsistent due to updates when the database is performing the update work
---> The database cannot have deletion exceptions when the database performs the delete work
Each component in the---> tuple is a data item that can not be re-divided, the database design should consider reasonable query and other related problems, in the data organization should be reasonable.

Liunx MySQL Database binary compression package The structure of the installation directory after decompression
"Bin"
==> client program and Mysqlid server
"Data"
==> log files, database
"Docs"
==> Documentation
"Include"
==> contains (header) files
"Lib"
==> Library
"Scripts"
==>mysql_install_db Script
"Share/mysql"
==> error Message File
"Sql-bench"
==> Benchmark Program

Liunx MySQL database using three paradigms, relational model design considerations, installation directory structure