database design options- better one

Question

User-1202579601 posted

StuFacultySubjId

Stu_id	Faculty_id	Subj_id

The three fields store fixed char type of data. So storing as a single field or as separate fields is better. I know to merge them while storing and separating them while

extracting from the database based on their fixed size and position.

Answer 1

User409696431 posted

Storing them separately is better.  Why incur the overhead of merging them and splitting them every time you store or read them?  And I assume you will want to use those individual values to query other tables in the database, at some point.

Answer 2

User-1202579601 posted

Stu_id char(10), FacultyId char(10), subjId char(10). Nearly 5000*200*6*10 in order records are being stored. So mergerid char(30). For this particular table, which is the beter way

in terms or performance.

Answer 3

User475983607 posted

Stu_id char(10), FacultyId char(10), subjId char(10). Nearly 5000*200*6*10 in order records are being stored. So mergerid char(30). For this particular table, which is the beter way

in terms or performance.

The approach decreases performance.  The fields should be separate not concatenated.

Answer 4

User379720387 posted

Why would you want to store foreign keys in char format?

Those should be INT.

You are building in unnecessary complexity, and 10 extra processing steps for the processor to convert char to binary.

Answer 5

User-893317190 posted

Hi pmdrait,

It seems your Stu_id, Faculty_id and Subj_id are all foreign key fields, which means every fields refers to a id column of another table separately.

How do you make them refer to another table when you combine them into a single field?

For example , if you want to find the subjects of a student , you should join the table with student table and subject table, if you combine them together , it will be hard to join tables.

If I misunderstand what you mean, please provide more information of what the fields means in you case and tables have relationship with the three fields .

Best regards,

Ackerly Xu