mysql - How to manage entity duplication in database table -


i working on simple database design of application. have book illustrator , editor table.

modelling 1 relation between enter image description here

with model, think here duplication of column name in each author editor , illustrator table.

what if book author, illustrator , editor person same, in case, data duplicated across 3 tables.

but in case of searching faster, guess no of items per table less.

modelling 2

enter image description here modeling, author, illustrator , editor info saved in single table , confused should name of table.

with approach. data won't' duplicated searching double compared model 1.

can suggest me model should choose. feel modeling 2 better.

it purely taste model should use. second 1 has advantage wont duplicates. both models can results 1 query

select * books left join names auth on (auth.id = author_id)  left join names ill on (ill.id = illustrator_id)  left join names ed on (ed.id = editor_id)  books.id = 1;

sqlfiddle gives example of model 2. if want obtain data model one, change 3 joins right table.

if want display list of authors, not recommend adding new field in names table, use joint query.

select auth.* books left join names auth on (auth.id = author_id)

as long set indexes on id, author_id, illustrator_id , editor_id, fine.

edit: preference go model 2. think might bit faster:

  1. the database needs open 1 file (not 3)
  2. there less records in table (compared combined of 3 tables) because don't have duplicates.
  3. the database need search through 1 index set (not 3) , might optimised stuff in because looking 3 keys in same set (instead of 3 key in 3 index sets) - it's gut feeling, not sure if correct...

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