= Нормализација на базата =

== Нормални форми по релации ==

||= Релација =||= Клуч(еви) =||= Функциски зависности (ФЗ) =||= Нормална форма =||
||'''Track(track_id, name, album_id, media_type_id, genre_id, composer, milliseconds, bytes)'''||track_id||track_id → {name, album_id, media_type_id, genre_id, composer, milliseconds, bytes}||BCNF||
||'''Album(album_id, title, artist_id)'''||album_id||album_id → {title, artist_id}||BCNF||
||'''Artist(artist_id, name)'''||artist_id||artist_id → name||BCNF||
||'''Genre(genre_id, name)'''||genre_id||genre_id → name||BCNF||
||'''MediaType(media_type_id, name)'''||media_type_id||media_type_id → name||BCNF||
||'''Price(price_id, value, date, track_id)'''||price_id||price_id → {value, date, track_id}||BCNF (ако price_id е surrogate); 3NF ако клуч е (track_id, date)||
||'''InvoiceLine(invoice_line_id, invoice_id, track_id, quantity)'''||invoice_line_id (и можен (invoice_id, track_id))||invoice_line_id → {invoice_id, track_id, quantity}; (invoice_id, track_id) → quantity||BCNF (со surrogate); 3NF (ако композитен клуч)||
||'''Invoice(invoice_id, customer_id, invoice_date, billing_address, billing_city, billing_state, billing_country, billing_postal_code, total)'''||invoice_id||invoice_id → {customer_id, invoice_date, billing_address, billing_city, billing_state, billing_country, billing_postal_code, total}||BCNF||
||'''Customer(customer_id, first_name, last_name, company, support_rep_id, address, city, state, country, postal_code, phone, fax, email)'''||customer_id||customer_id → {first_name, last_name, company, support_rep_id, address, city, state, country, postal_code, phone, fax, email}||BCNF||
||'''Employee(employee_id, first_name, last_name, title, reports_to, birth_date, hire_date, address, city, state, country, postal_code, phone, fax, email)'''||employee_id||employee_id → {first_name, last_name, title, reports_to, birth_date, hire_date, address, city, state, country, postal_code, phone, fax, email}||BCNF||
||'''Playlist(playlist_id, name)'''||playlist_id||playlist_id → name||BCNF||
||'''PlaylistTrack(playlist_track_id, playlist_id, track_id)'''||playlist_track_id (и можен (playlist_id, track_id))||playlist_track_id → {playlist_id, track_id}; (playlist_id, track_id) → playlist_track_id||BCNF||

== Заклучок ==
  * Сите релации се барем во **3-та нормална форма (3NF)**.