{"id":115,"date":"2014-09-25T00:03:47","date_gmt":"2014-09-25T00:03:47","guid":{"rendered":"https:\/\/www.uniessa.hiperlogic.com.br\/?p=115"},"modified":"2014-09-25T00:22:56","modified_gmt":"2014-09-25T00:22:56","slug":"algoritmos-de-projeto-de-bd","status":"publish","type":"post","link":"https:\/\/www.uniessa.hiperlogic.com.br\/?p=115","title":{"rendered":"Algoritmos de projeto de BD"},"content":{"rendered":"<ul>\n<li>deduzir depend\u00eancias funcionais a partir de um conjunto dado;<\/li>\n<li>jun\u00e7\u00e3o sem perda e preserva\u00e7\u00e3o de depend\u00eancias funcionais;<\/li>\n<li>projeto relacional por s\u00edntese;<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><strong>Fecho de DF &#8211; F+<\/strong><br \/>\nSeja F o conjunto de depend\u00eancias funcionais que s\u00e3o especificadas no esquema de rela\u00e7\u00e3o R, o conjunto de todas as depend\u00eancias que incluem F e todas as depend\u00eancias que podem ser deduzidas de F, \u00e9 chamado de fechamento de F, ou fecho de F, sendo denotado por F+.<br \/>\nObs.: uma DF X \u2192 Y \u00e9 deduzida de um conjunto de depend\u00eancias F especificado em R, SE:<br \/>\nSempre que r satisfizer todas as depend\u00eancias em F, \u00a0ENT\u00c3O X \u2192 Y tamb\u00e9m se mant\u00e9m em r.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Fecho de DF \u2013 F+ &#8211; Exemplo<\/strong><br \/>\nF = {(Dep_nr \u2192 Cpf_gerente), (Cpf_gerente \u2192 Telefone_ger)}<br \/>\nF |= (Dep_ nr \u2192 Telefone_ger); % L\u00ea-se: de F deduzimos&#8230;<br \/>\nComo n\u00e3o h\u00e1 mais DF a deduzir de F, temos que:<br \/>\nF+ = F \u222a {(Dep_ nr \u2192 Telefone_ger)}<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Regras de infer\u00eancia em DF<\/strong><\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.50.22.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-116\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.50.22-300x184.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 20.50.22\" width=\"300\" height=\"184\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.50.22-300x184.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.50.22.png 835w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Fecho de X sob F &#8211; X+<\/strong><\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.52.40.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-117\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.52.40-285x300.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 20.52.40\" width=\"285\" height=\"300\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.52.40-285x300.png 285w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.52.40.png 462w\" sizes=\"auto, (max-width: 285px) 100vw, 285px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>X+\u00a0sob F &#8211; Exemplo<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.53.40.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-118\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.53.40-300x293.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 20.53.40\" width=\"300\" height=\"293\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.53.40-300x293.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.53.40.png 494w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p><strong>Equival\u00eancia de conjuntos de DF<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.54.28.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-119\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.54.28-300x273.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 20.54.28\" width=\"300\" height=\"273\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.54.28-300x273.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.54.28.png 525w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Equival\u00eancia de conjuntos de DF \u2013 <\/strong><br \/>\n<strong>Exemplo\/Exerc\u00edcio calcule F+ e G+<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.55.38.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-120\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.55.38-300x222.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 20.55.38\" width=\"300\" height=\"222\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.55.38-300x222.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.55.38.png 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Conjunto m\u00ednimo de DF<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.56.02.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-121\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.56.02-300x250.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 20.56.02\" width=\"300\" height=\"250\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.56.02-300x250.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.56.02.png 435w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Cobertura m\u00ednima de F<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.57.11.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-123\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.57.11-300x174.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 20.57.11\" width=\"300\" height=\"174\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.57.11-300x174.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-20.57.11.png 558w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Alg. 16.2 &#8211; Cobertura m\u00ednima de F<\/strong><br \/>\n<strong>Alg. 16.2a \u2013 Chave<\/strong><\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.05.08.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-125\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.05.08-300x176.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.05.08\" width=\"300\" height=\"176\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.05.08-300x176.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.05.08.png 859w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Decomposi\u00e7\u00e3o de R<\/strong><\/p>\n<p>O conjunto F de depend\u00eancias funcionais que devem ser mantidas nos atributos de R \u00e9 especificado pelos projetistas de banco de dados e se torna dispon\u00edvel aos algoritmos de projeto.<br \/>\nAo utilizar as depend\u00eancias funcionais, os algoritmos decomp\u00f5em o esquema de rela\u00e7\u00e3o universal R em um conjunto de esquemas de rela\u00e7\u00e3o D = {R1, R2, &#8230;, Rm}, que se tornar\u00e1 o esquema do banco de dados relacional; D \u00e9 chamado de decomposi\u00e7\u00e3o de R.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Preserva\u00e7\u00e3o de atributo<\/strong><\/p>\n<p>D = {R1, R2, &#8230;, Rm}, temos de garantir que cada atributo em R aparecer\u00e1 em pelo menos um esquema de rela\u00e7\u00e3o Ri na decomposi\u00e7\u00e3o, de modo que nenhum atributo seja perdido. Formalmente, temos<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.09.52.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-126\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.09.52.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.09.52\" width=\"126\" height=\"93\" \/><\/a><\/p>\n<p>Esta \u00e9 chamada de condi\u00e7\u00e3o de preserva\u00e7\u00e3o de atributo de uma decomposi\u00e7\u00e3o.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Preserva\u00e7\u00e3o de depend\u00eancia &#8211; Intui\u00e7\u00e3o<\/strong><\/p>\n<p>Seria \u00fatil se cada depend\u00eancia funcional X\u2192Y especificada em F aparecesse diretamente em um dos esquemas de rela\u00e7\u00e3o Ri na decomposi\u00e7\u00e3o D ou\u00a0pudesse ser deduzida das depend\u00eancias que aparecem em alguma Ri.<br \/>\nInformalmente, essa \u00e9 a condi\u00e7\u00e3o de preserva\u00e7\u00e3o de depend\u00eancia<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Preserva\u00e7\u00e3o de depend\u00eancia &#8211; Defini\u00e7\u00e3o<\/strong><\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.11.17.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-127\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.11.17-300x238.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.11.17\" width=\"300\" height=\"238\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.11.17-300x238.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.11.17.png 528w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Preserva\u00e7\u00e3o de depend\u00eancia e 3FN<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.13.09.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-128\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.13.09-300x249.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.13.09\" width=\"300\" height=\"249\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.13.09-300x249.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.13.09.png 562w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Jun\u00e7\u00e3o sem perda (n\u00e3o aditiva)<\/strong><\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.14.23.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-129\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.14.23-300x137.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.14.23\" width=\"300\" height=\"137\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.14.23-300x137.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.14.23.png 612w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p><strong>Alg. 16.3 \u2013 Testa jun\u00e7\u00e3o n\u00e3o aditiva\u00a0<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.16.31.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-130\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.16.31-300x187.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.16.31\" width=\"300\" height=\"187\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.16.31-300x187.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.16.31.png 774w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.17.17.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-131\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.17.17-300x228.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.17.17\" width=\"300\" height=\"228\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.17.17-300x228.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.17.17.png 842w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Teste de jun\u00e7\u00e3o n\u00e3o aditiva para <\/strong><br \/>\n<strong>decomposi\u00e7\u00f5es bin\u00e1rias<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.18.12.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-132\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.18.12-300x134.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.18.12\" width=\"300\" height=\"134\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.18.12-300x134.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.18.12.png 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Decomposi\u00e7\u00f5es sucessivas<\/strong><\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.18.51.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-133\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.18.51-300x189.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.18.51\" width=\"300\" height=\"189\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.18.51-300x189.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.18.51.png 632w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Preserva\u00e7\u00e3o de depend\u00eancia e 3FN<\/strong><\/p>\n<p>O Algoritmo 16.4, a seguir, cria uma decomposi\u00e7\u00e3o de preserva\u00e7\u00e3o de depend\u00eancia D = {R1, R2, &#8230;, Rm} de uma rela\u00e7\u00e3o universal R com base em um conjunto de depend\u00eancias funcionais F, tal que cada Ri em D est\u00e1 na 3FN.<br \/>\n<strong><em>Isso garante apenas a propriedade de preserva\u00e7\u00e3o de depend\u00eancia; mas n\u00e3o garante a propriedade de jun\u00e7\u00e3o n\u00e3o aditiva.<\/em><\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Alg. 16.4 \u2013 S\u00edntese para 3FN com preserva\u00e7\u00e3o de depend\u00eancia<\/strong><\/p>\n<p><a href=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.20.32.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-134\" src=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.20.32-300x219.png\" alt=\"Captura de Tela 2014-09-24 \u00e0s 21.20.32\" width=\"300\" height=\"219\" srcset=\"https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.20.32-300x219.png 300w, https:\/\/www.uniessa.hiperlogic.com.br\/wp-content\/uploads\/2014\/09\/Captura-de-Tela-2014-09-24-\u00e0s-21.20.32.png 604w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>deduzir depend\u00eancias funcionais a partir de um conjunto dado; jun\u00e7\u00e3o sem perda e preserva\u00e7\u00e3o de depend\u00eancias funcionais; projeto relacional por s\u00edntese; &nbsp; Fecho de DF &#8211; F+ Seja F o conjunto de depend\u00eancias funcionais que s\u00e3o especificadas no esquema de rela\u00e7\u00e3o R, o conjunto de todas as depend\u00eancias que incluem F e todas as depend\u00eancias [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-115","post","type-post","status-publish","format-standard","hentry","category-bd"],"_links":{"self":[{"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=\/wp\/v2\/posts\/115","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=115"}],"version-history":[{"count":3,"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=\/wp\/v2\/posts\/115\/revisions"}],"predecessor-version":[{"id":135,"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=\/wp\/v2\/posts\/115\/revisions\/135"}],"wp:attachment":[{"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=115"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=115"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.uniessa.hiperlogic.com.br\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=115"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}