wiki:Version3

Version 5 (modified by 212016, 3 months ago) ( diff )

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Верзија 3

Определување функциски зависности и да нема нешто со исто име на атрибут

*s_id = statement_id R={ pe_id, first_name, last_name, gender, address, picture, contact, embg, date_of_birth,country, nationality, o_badge_no, o_password, o_date_of_employment, p_id, p_address, s_id, city, p_date_of_employment, badge_no, rank, p_password, statement_id, statement_date, description, incident_timestamp, incident_place, e_id, e_name, e_type, is_found, e_picture, c_id, c_name, opening_date, c_status, date_of_closing, sc_description, final_document, t_id, t_name }

pe_id -> first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality o_badge_no -> s_id, pe_id, o_password, o_date_of_employment p_id -> p_address, o_badge_no, s_id s_id -> city badge_no -> pe_id, p_date_of_employment, rank, p_password statement_id -> c_id, statement_date, description, incident_timestamp, incident_place, badge_no e_id -> e_name, e_type, is_found, e_picture c_id -> c_name, opening_date, c_status, e_id, p_id, date_of_closing final_document-> sc_description, date_of_closing t_id -> t_name

### Лево

  • statement_id
  • final_document
  • t_id

### Десно

  • first_name
  • last_name
  • gender
  • address
  • picture
  • contact
  • embg
  • date_of_birth
  • country
  • nationality
  • o_password
  • o_date_of_employment
  • p_address
  • city
  • p_date_of_employment
  • rank
  • p_password
  • statement_date
  • description
  • incident_timestamp
  • incident_place
  • e_name
  • e_type
  • is_found
  • e_picture
  • c_name
  • opening_date
  • c_status
  • sc_description
  • t_name
  • date_of_closing

### Двете

  • pe_id
  • o_badge_no
  • p_id
  • s_id
  • badge_no
  • e_id
  • c_id

statement_id+={statement_id ,c_id, statement_date, description, incident_timestamp, incident_place, badge_no,c_name, opening_date, c_status, e_id, p_id, date_of_closing, pe_id, p_date_of_employment, rank, p_password, first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality, p_address, o_badge_no, s_id, city, e_name, e_type, is_found, e_picture}

не ги содржи сите атрибути

final_document+={final_document, sc_description, date_of_closing} не ги содржи сите атрибути

t_id+={t_id, t_name} не ги содржи сите атрибути

statement_id, final_document+={statement_id, final_document, c_id, statement_date, description, incident_timestamp, incident_place, badge_no, sc_description, date_of_closing, c_name, opening_date, c_status, e_id, p_id, pe_id, p_date_of_employment, rank, p_password, first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality, p_address, o_badge_no, s_id, city e_name, e_type, is_found, e_picture} не ги содржи сите атрибути

statement_id, t_id+={statement_id, t_id, c_id, statement_date, description, incident_timestamp, incident_place, badge_no, t_name, c_name, opening_date, c_status, e_id, p_id, date_of_closing, e_name, e_type, is_found, e_picture, p_address, o_badge_no, s_id, city, pe_id, p_date_of_employment, rank, p_password, first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality, o_password, o_date_of_employment} не ги содржи сите атрибути

final_document, t_id+={final_document, t_id, sc_description, date_of_closing, t_name} не ги содржи сите атрибути

final_document, t_id, statement_id+={final_document, t_id, statement_id, sc_description, date_of_closing, t_name, c_id, statement_date, description, incident_timestamp, incident_place, badge_no, c_name, opening_date, c_status, e_id, p_id, pe_id, p_date_of_employment, rank, p_password, e_name, e_type, is_found, e_picture, p_address, o_badge_no, s_id, o_password, o_date_of_employment, city, first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality} Следува дека е единствен кандидат клуч и го прогласуваме за примарен клуч. `

в) Во ваква дефинирана релација нема повеќекратни зависности, па со тоа следува дека задоволува 1НФ.

Парцијална зависност постои, и со тоа заклучуваме дека не е задоволена 2НФ.

Декомпозиција:

R1{s_id, city} е во BCNF

R2{c_id, final_document, t_id, statement_id, sc_description, date_of_closing, t_name, c_id, statement_date, description, incident_timestamp, incident_place, badge_no, c_name, opening_date, c_status, e_id, p_id, pe_id, p_date_of_employment, rank, p_password, e_name, e_type, is_found, e_picture, p_address, o_badge_no, s_id, o_password, o_date_of_employment, first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality}

---

R2 не е во 3НФ поради e_id -> e_name, e_type, is_found, e_picture

R21{e_id, e_name, e_type, is_found, e_picture} е во BCNF

R22{ final_document, t_id, statement_id, sc_description, date_of_closing, t_name, c_id, statement_date, description, incident_timestamp, incident_place, badge_no, c_name, opening_date, c_status, e_id, p_id, pe_id, p_date_of_employment, rank, p_password, p_address, o_badge_no, s_id, o_password, o_date_of_employment, first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality}

---

R22 не е во 3НФ поради pe_id -> first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality

R221{pe_id, first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality}е во BCNF

R222{ final_document, t_id, statement_id, sc_description, date_of_closing, t_name, c_id, statement_date, description, incident_timestamp, incident_place, badge_no, c_name, opening_date, c_status, e_id, p_id, pe_id, p_date_of_employment, rank, p_password, p_address, o_badge_no, s_id, o_password, o_date_of_employment

---

R222 не е во 3НФ поради bange_no → pe_id, p_date_of_employment, rank, p_password

R2221{badge_no, pe_id, p_date_of_employment, rank, p_password} е во BCNF R2222{final_document, t_id, statement_id, sc_description, date_of_closing, t_name, c_id, statement_date, description, incident_timestamp, incident_place, badge_no, c_name, opening_date, c_status, e_id, p_id, p_address, o_badge_no, s_id, o_password, o_date_of_employment}

---

R2222 не е во 3НФ поради o_badge_no -> s_id, pe_id, o_password, o_date_of_employment

R22221{o_badge_no, s_id, pe_id, o_password, o_date_of_employment} е во BCNF R22222{final_document, t_id, statement_id, sc_description, date_of_closing, t_name, c_id, statement_date, description, incident_timestamp, incident_place, badge_no, c_name, opening_date, c_status, e_id, p_id, p_address, o_badge_no}

---

R22222 не е во 3НФ поради p_id -> p_address, o_badge_no, s_id

R222221{p_id, p_address, o_badge_no, s_id}е во BCNF R222222{final_document, t_id, statement_id, sc_description, date_of_closing, t_name, c_id, statement_date, description, incident_timestamp, incident_place, badge_no, c_name, opening_date, c_status, e_id, p_id}

---

R222222 не е во 3НФ поради c _id -> c_name, opening_date, c_status, e_id, p_id, date_of_closing

R2222221{c_id, c_name, opening_date, c_status, e_id, p_id, date_of_closing}е во BCNF R2222222{final_document, t_id, statement_id, sc_description, t_name, c_id, statement_date, description, incident_timestamp, incident_place, badge_no}

---

R2222222 не е во 3НФ поради t_id -> t_name

R222222221{t_id, t_name} е во BCNF R222222222{final_document, t_id, statement_id, sc_description, c_id, statement_date, description, incident_timestamp, incident_place, badge_no}

---

R222222222 не е во 3НФ поради final_document-> sc_description, date_of_closing

R222222221{final_document, sc_description, date_of_closing}е во BCNF R222222222{final_document, t_id, statement_id, c_id, statement_date, description, incident_timestamp, incident_place, badge_no}

---

R222222222 не е во 3НФ поради statement_id -> c_id, statement_date, description, incident_timestamp, incident_place, badge_no

R2222222221{statement_id , c_id, statement_date, description, incident_timestamp, incident_place, badge_no}е во BCNF

R2222222222{final_document, t_id, statement_id} е во BCNF

Релации

Sector_of_interal_affairs{s_id, city} е во BCNF

Evidence{e_id, e_name, e_type, is_found, e_picture} е во BCNF

People{pe_id, first_name, last_name, gender, address, picture, contact, embg, date_of_birth, country, nationality}е во BCNF

Policeman{badge_no, pe_id, p_date_of_employment, rank, p_password} е во BCNF

Officer{o_badge_no, s_id, pe_id, o_password, o_date_of_employment} е во BCNF

Police_station{p_id, p_address, o_badge_no, s_id}е во BCNF

Crime_case{c_id, c_name, opening_date, c_status, e_id, p_id, date_of_closing}е во BCNF

Type_of_crime{t_id, t_name} е во BCNF

Solved_case{final_document, sc_description, date_of_closing}е во BCNF

Statement{statement_id , c_id, statement_date, description, incident_timestamp, incident_place, badge_no}е во BCNF

Statement_and_case{final_document, t_id, statement_id} е во BCNF

*резултатот е различен од оригиналниот модел.

Дискусија на разликите:

Табелите каде што се чуваат acused, witness и victims се испуштаат. За да се реши ова би можело да има индиректна врска преку Statements со атрибут statement_of каде што можеме да имаме три вредности соодветно acused, witness и victims.

Редундантно повторување на слични атрибути, тоа се забележува кај Officer и Policeman. Едно решение за ова би било табела вработени каде што би се чувал атрибут is_officer. Со тоа би се изменила целосната структура на базата и не би ги имале officer и policeman.

Имаме исто така директна врска од Crime_case за Evidence, каде што во првичниот модел се индиректно поврзани преку Mentions_evidence и Statements.

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