tag:blogger.com,1999:blog-35188173612767846562024-02-08T12:05:26.311-08:00Normalización de Base de DatosBryanhttp://www.blogger.com/profile/05472394431987534865noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-3518817361276784656.post-50427099655721362112009-08-24T14:48:00.001-07:002009-08-24T14:52:46.117-07:00Definición<p style="text-align: justify;">El proceso de <b>normalización de <a href="http://es.wikipedia.org/wiki/Base_de_datos" title="Base de datos">bases de datos</a></b> consiste en aplicar una serie de reglas a las relaciones obtenidas tras el paso del <a href="http://es.wikipedia.org/wiki/Modelo_E-R" title="Modelo E-R" class="mw-redirect">modelo entidad-relación</a> al <a href="http://es.wikipedia.org/wiki/Modelo_relacional" title="Modelo relacional">modelo relacional</a>.</p><div style="text-align: justify;"> </div><p style="text-align: justify;">Las bases de datos relacionales se normalizan para:</p><div style="text-align: justify;"> </div><ul style="text-align: justify;"><li>Evitar la <a href="http://es.wikipedia.org/wiki/Redundancia" title="Redundancia">redundancia</a> de los datos.</li><li>Evitar problemas de actualización de los datos en las tablas.</li><li>Proteger la <a href="http://es.wikipedia.org/wiki/Integridad" title="Integridad">integridad</a> de los datos.</li></ul><div style="text-align: justify;"> </div><p style="text-align: justify;">En el modelo relacional es frecuente llamar <i><a href="http://es.wikipedia.org/wiki/Tabla_%28base_de_datos%29" title="Tabla (base de datos)">tabla</a></i> a una relación, aunque para que una tabla sea considerada como una relación tiene que cumplir con algunas restricciones:</p><div style="text-align: justify;"> </div><ul style="text-align: justify;"><li>Cada columna debe tener su nombre único.</li><li>No puede haber dos <a href="http://es.wikipedia.org/wiki/Fila_%28base_de_datos%29" title="Fila (base de datos)" class="mw-redirect">filas</a> iguales. No se permiten los duplicados.</li><li>Todos los datos en una <a href="http://es.wikipedia.org/wiki/Columna_%28base_de_datos%29" title="Columna (base de datos)">columna</a> deben ser del mismo tipo.</li></ul>Bryanhttp://www.blogger.com/profile/05472394431987534865noreply@blogger.com0tag:blogger.com,1999:blog-3518817361276784656.post-56678019477404133772009-08-24T14:47:00.001-07:002009-08-24T14:47:46.488-07:00Formas Normales<p style="text-align: justify;">Las formas normales son aplicadas a las tablas de una base de datos. Decir que una base de datos está en la forma normal <b>N</b> es decir que todas sus tablas están en la forma normal <b>N</b>.</p><div style="text-align: justify;"> En general, las primeras tres formas normales son suficientes para cubrir las necesidades de la mayoría de las bases de datos. El creador de estas 3 primeras formas normales (o reglas) fue <a href="http://es.wikipedia.org/wiki/Edgar_F._Codd" title="Edgar F. Codd" class="mw-redirect">Edgar F. Codd</a>.</div>Bryanhttp://www.blogger.com/profile/05472394431987534865noreply@blogger.com0tag:blogger.com,1999:blog-3518817361276784656.post-11572936965206835002009-08-24T14:45:00.000-07:002009-08-24T14:46:55.547-07:00Primera Forma Normal (1FN)<p style="text-align: justify;">Una tabla está en Primera Forma Normal sólo si</p><div style="text-align: justify;"> </div><ul style="text-align: justify;"><li>Todos los atributos son atómicos. Un atributo es atómico si los elementos del dominio son indivisibles, mínimos.</li><li>La tabla contiene una clave primaria.</li><li>La tabla no contiene atributos nulos.</li><li>Si no posee ciclos repetitivos.</li></ul><div style="text-align: justify;"> </div><p style="text-align: justify;">Una columna no puede tener múltiples valores. Los datos son atómicos. (Si a cada valor de X le pertenece un valor de Y, entonces a cada valor de Y le pertenece un valor de X)</p><div style="text-align: justify;"> </div><p style="text-align: justify;">Esta forma normal elimina los valores repetidos dentro de una BD</p>Bryanhttp://www.blogger.com/profile/05472394431987534865noreply@blogger.com0tag:blogger.com,1999:blog-3518817361276784656.post-38854681706804622202009-08-24T14:44:00.000-07:002009-08-24T14:45:34.873-07:00Ejemplo Primera Forma Normal (1FN)<p style="margin-bottom: 0.0001pt;"><span style="font-size: 12pt; font-family: "Times New Roman";">A través del siguiente ejercicio se intenta afirmar los conocimientos de normalización con un ejemplo simplificado de una base de datos para una pequeña biblioteca.<o:p></o:p></span></p> <p style="margin-bottom: 0.0001pt;"><o:p> </o:p></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 435.75pt; margin-left: 3.75pt;" border="1" cellpadding="0" cellspacing="0" width="581"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.8pt;" valign="top" width="61"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLibro</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 90.2pt;" valign="top" width="120"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Titulo</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 84.65pt;" valign="top" width="113"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Autor</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.6pt;" valign="top" width="98"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Editorial</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 85.45pt;" valign="top" width="114"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">NombreLector</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 56.05pt;" valign="top" width="75"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">FechaDev</span></b></span><b><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.8pt;" width="61"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1001</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 90.2pt;" width="120"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Variable compleja</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 84.65pt;" width="113"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Murray</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Spiegel</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.6pt;" width="98"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 85.45pt;" width="114"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Pérez Gómez, Juan</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 56.05pt;" width="75"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">15/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.8pt;" width="61"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1004</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 90.2pt;" width="120"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Visual Basic 5</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 84.65pt;" width="113"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">E. <span class="SpellE">Petroustsos</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.6pt;" width="98"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Anaya</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 85.45pt;" width="114"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Ríos Terán, Ana</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 56.05pt;" width="75"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">17/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.8pt;" width="61"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1005</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 90.2pt;" width="120"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Estadística</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 84.65pt;" width="113"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Murray</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Spiegel</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.6pt;" width="98"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 85.45pt;" width="114"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Roca, René</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 56.05pt;" width="75"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">16/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.8pt;" width="61"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 90.2pt;" width="120"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">University</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 84.65pt;" width="113"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";" lang="EN-GB">Nancy Greenberg y Priya Nathan</span><span style="" lang="EN-GB"><o:p></o:p></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.6pt;" width="98"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Corp</span>.</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 85.45pt;" width="114"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">García Roque, Luis</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 56.05pt;" width="75"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">20/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.8pt;" width="61"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1007</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 90.2pt;" width="120"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Clipper</span></span><span style="font-family: "Times New Roman";"> 5.01</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 84.65pt;" width="113"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Ramalho</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.6pt;" width="98"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 85.45pt;" width="114"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Pérez Gómez, Juan</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 56.05pt;" width="75"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">18/04/2005</span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt;"><span style="font-size: 12pt; font-family: "Times New Roman";">Esta tabla no cumple el requisito de la Primera Forma Normal (1NF) de sólo tener campos atómicos, pues el nombre del lector es un campo que puede (y conviene) descomponerse en apellido paterno, apellido materno y nombres. Tal como se muestra en la siguiente tabla.</span></p> <p style="margin-bottom: 0.0001pt;"><b><span style="font-size: 12pt; font-family: "Times New Roman";">1NF</span></b></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 458.25pt;" border="1" cellpadding="0" cellspacing="0" width="611"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 49.4pt;" valign="top" width="66"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLibro</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 80.35pt;" valign="top" width="107"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Titulo</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78.1pt;" valign="top" width="104"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Autor</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.9pt;" valign="top" width="80"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Editorial</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.35pt;" valign="top" width="56"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Paterno</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.3pt;" valign="top" width="60"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Materno</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 47.05pt;" valign="top" width="63"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Nombres</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 55.8pt;" valign="top" width="74"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">FechaDev</span></b></span><b><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 49.4pt;" width="66"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1001</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 80.35pt;" width="107"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Variable compleja</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78.1pt;" width="104"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Murray</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Spiegel</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.9pt;" width="80"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.35pt;" width="56"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Pérez</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.3pt;" width="60"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Gómez</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 47.05pt;" width="63"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Juan</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 55.8pt;" width="74"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">15/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 49.4pt;" width="66"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1004</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 80.35pt;" width="107"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Visual Basic 5</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78.1pt;" width="104"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">E. <span class="SpellE">Petroustsos</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.9pt;" width="80"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Anaya</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.35pt;" width="56"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Ríos</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.3pt;" width="60"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Terán</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 47.05pt;" width="63"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Ana</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 55.8pt;" width="74"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">17/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 49.4pt;" width="66"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1005</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 80.35pt;" width="107"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Estadística</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78.1pt;" width="104"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Murray</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Spiegel</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.9pt;" width="80"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.35pt;" width="56"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Roca</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.3pt;" width="60"> <p class="NormalWeb1"><o:p> </o:p></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 47.05pt;" width="63"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">René</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 55.8pt;" width="74"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">16/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 49.4pt;" width="66"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 80.35pt;" width="107"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">University</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78.1pt;" width="104"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Nancy <span class="SpellE">Greenberg</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.9pt;" width="80"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Corp</span>.</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.35pt;" width="56"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">García</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.3pt;" width="60"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Roque</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 47.05pt;" width="63"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Luis</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 55.8pt;" width="74"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">20/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 49.4pt;" width="66"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 80.35pt;" width="107"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">University</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78.1pt;" width="104"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Priya</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Nathan</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.9pt;" width="80"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Corp</span>.</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.35pt;" width="56"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">García</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.3pt;" width="60"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Roque</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 47.05pt;" width="63"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Luis</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 55.8pt;" width="74"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">20/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 49.4pt;" width="66"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1007</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 80.35pt;" width="107"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Clipper</span></span><span style="font-family: "Times New Roman";"> 5.01</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78.1pt;" width="104"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Ramalho</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.9pt;" width="80"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.35pt;" width="56"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Pérez</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.3pt;" width="60"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Gómez</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 47.05pt;" width="63"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Juan</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 55.8pt;" width="74"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">18/04/2005</span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt;"><span style="font-size: 12pt; font-family: "Times New Roman";">Como se puede ver, hay cierta redundancia característica de 1NF. </span></p>Bryanhttp://www.blogger.com/profile/05472394431987534865noreply@blogger.com0tag:blogger.com,1999:blog-3518817361276784656.post-5015908247775931612009-08-24T14:43:00.000-07:002009-08-24T14:44:23.775-07:00Segunda Forma Normal (2FN)<p style="text-align: justify;"><b>Dependencia Funcional.</b> Una relación está en 2FN si está en 1FN y si los atributos que no forman parte de ninguna clave dependen de forma completa de la clave principal. Es decir que no existen dependencias parciales.</p><div style="text-align: justify;"> </div><p style="text-align: justify;">En otras palabras podríamos decir que la segunda forma normal está basada en el concepto de dependencia completamente funcional. Una dependencia funcional <img class="tex" alt="x \rightarrow y" src="http://upload.wikimedia.org/math/0/c/3/0c351748eea04152a2d97216b2dbbff3.png" /> es completamente funcional si al eliminar los atributos A de X significa que la dependencia no es mantenida, esto es que A Є X, (X – {A}) -x-> Y. Una dependencia funcional <img class="tex" alt="x \rightarrow y" src="http://upload.wikimedia.org/math/0/c/3/0c351748eea04152a2d97216b2dbbff3.png" /> es una dependencia parcial si hay algunos atributos <img class="tex" alt="A \in X" src="http://upload.wikimedia.org/math/7/7/7/777e0da90c2254c651295454713e380a.png" /> que pueden ser removidos de X y la dependencia todavía se mantiene, esto es A Є X, (X – {A}) -> Y .</p><div style="text-align: justify;"> </div><p style="text-align: justify;">Por ejemplo {SSN, PNUMBER} <img class="tex" alt="\rightarrow" src="http://upload.wikimedia.org/math/8/3/e/83e37b7246fdfcb99b2754210ebeae27.png" /> HOURS es completamente dependiente dado que ni SSN <img class="tex" alt="\rightarrow" src="http://upload.wikimedia.org/math/8/3/e/83e37b7246fdfcb99b2754210ebeae27.png" /> HOURS ni PNUMBER <img class="tex" alt="\rightarrow" src="http://upload.wikimedia.org/math/8/3/e/83e37b7246fdfcb99b2754210ebeae27.png" /> HOURS mantienen la dependencia. Sin embargo {SSN, PNUMBER} <img class="tex" alt="\rightarrow" src="http://upload.wikimedia.org/math/8/3/e/83e37b7246fdfcb99b2754210ebeae27.png" /> ENAME es parcialmente dependiente dado que SSN <img class="tex" alt="\rightarrow" src="http://upload.wikimedia.org/math/8/3/e/83e37b7246fdfcb99b2754210ebeae27.png" /> ENAME mantiene la dependencia</p>Bryanhttp://www.blogger.com/profile/05472394431987534865noreply@blogger.com0tag:blogger.com,1999:blog-3518817361276784656.post-929667413900330642009-08-24T14:41:00.000-07:002009-08-24T14:43:37.354-07:00Ejemplo Segunda Forma Normal (2FN)<p style="margin-bottom: 0.0001pt; text-align: justify;"><span style="font-size: 12pt; font-family: "Times New Roman";">La Segunda Forma Normal (2NF) pide que no existan dependencias parciales o dicho de otra manera, todos los atributos no clave deben depender por completo de la clave primaria. Actualmente en nuestra tabla tenemos varias dependencias parciales si consideramos como atributo clave el código del libro.</span></p><div> </div><p style="margin-bottom: 0.0001pt; text-align: justify;"><span style="font-size: 12pt; font-family: "Times New Roman";">Por ejemplo, el título es completamente identificado por el código del libro, pero el nombre del lector en realidad no tiene dependencia de este código, por tanto estos datos deben ser trasladados a otra tabla.</span></p> <p style="margin-bottom: 0.0001pt;"><span style="font-size: 12pt; font-family: "Times New Roman";">2NF</span></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 284.25pt;" border="1" cellpadding="0" cellspacing="1" width="379"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" valign="top" width="58"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLibro</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 91.5pt;" valign="top" width="122"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Titulo</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 68.25pt;" valign="top" width="91"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Autor</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 52.5pt;" valign="top" width="70"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Editorial</span><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" width="58"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1001</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 91.5pt;" width="122"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Variable compleja</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 68.25pt;" width="91"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Murray</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Spiegel</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 52.5pt;" width="70"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" width="58"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1004</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 91.5pt;" width="122"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Visual Basic 5</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 68.25pt;" width="91"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">E. <span class="SpellE">Petroustsos</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 52.5pt;" width="70"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Anaya</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" width="58"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1005</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 91.5pt;" width="122"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Estadística</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 68.25pt;" width="91"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Murray</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Spiegel</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 52.5pt;" width="70"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" width="58"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 91.5pt;" width="122"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">University</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 68.25pt;" width="91"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Nancy <span class="SpellE">Greenberg</span> </span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 52.5pt;" width="70"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Corp</span>.</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" width="58"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 91.5pt;" width="122"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">University</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 68.25pt;" width="91"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Priya</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Nathan</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 52.5pt;" width="70"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Corp</span>.</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" width="58"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">1007</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 91.5pt;" width="122"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Clipper</span></span><span style="font-family: "Times New Roman";"> 5.01</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 68.25pt;" width="91"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Ramalho</span></span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 52.5pt;" width="70"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt;"><o:p> </o:p></p> <p style="margin-bottom: 0.0001pt;"><span style="font-size: 12pt; font-family: "Times New Roman";">La nueva tabla sólo contendrá datos del lector.<o:p></o:p></span></p> <p style="margin-bottom: 0.0001pt;"><o:p> </o:p></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 186.75pt;" border="1" cellpadding="0" cellspacing="1" width="249"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="top" width="61"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLector</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" valign="top" width="48"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Paterno</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" valign="top" width="49"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Materno</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="top" width="53"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Nombres</span><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" width="61"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">501</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" width="48"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Pérez</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" width="49"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Gómez</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" width="53"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Juan</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" width="61"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">502</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" width="48"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Ríos </span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" width="49"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Terán</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" width="53"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Ana</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" width="61"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">503</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" width="48"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Roca</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" width="49"> <p class="NormalWeb1"><o:p> </o:p></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" width="53"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">René</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" width="61"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">504</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" width="48"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">García</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" width="49"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Roque</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" width="53"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Luis</span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt; text-align: justify;"><span style="font-size: 12pt; font-family: "Times New Roman";">Hemos creado una tabla para contener los datos del lector y también tuvimos que crear la columna <span class="SpellE">CodLector</span> para identificar unívocamente a cada uno. Sin embargo, esta nueva disposición de la base de datos necesita que exista otra tabla para mantener la información de qué libros están prestados a qué lectores. Esta tabla se muestra a continuación:</span></p> <p style="margin-bottom: 0.0001pt;"><o:p> </o:p></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 152.25pt; margin-left: 36pt;" border="1" cellpadding="0" cellspacing="1" width="203"><thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="top" width="56"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLibro</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="top" width="61"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLector</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="top" width="56"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">FechaDev</span></b></span><b><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1001</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="bottom" width="61"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">501</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">15/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1004</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="bottom" width="61"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">502</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">17/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1005</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="bottom" width="61"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">503</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">16/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="bottom" width="61"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">504</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">20/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1007</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="bottom" width="61"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">501</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42pt;" valign="bottom" width="56"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">18/04/2005</span></p></td></tr></tbody></table>Bryanhttp://www.blogger.com/profile/05472394431987534865noreply@blogger.com0tag:blogger.com,1999:blog-3518817361276784656.post-65951338968793031652009-08-24T14:40:00.000-07:002009-08-24T14:41:45.290-07:00Tercera Forma Normal (3FN)<p style="text-align: justify;">La tabla se encuentra en 3FN si es 2FN y cada atributo que no forma parte de ninguna clave, depende directamente y no transitivamente, de la clave primaria.</p><div style="text-align: justify;"> </div><p style="text-align: justify;">Un ejemplo de este concepto sería que, una dependencia funcional X->Y en un esquema de relación R es una dependencia transitiva si hay un conjunto de atributos Z que no es un subconjunto de alguna clave de R, donde se mantiene X->Z y Z->Y.</p><div style="text-align: justify;"> </div><p style="text-align: justify;">Por ejemplo, la dependencia SSN->DMGRSSN es una dependencia transitiva en EMP_DEPT de la siguiente figura. Decimos +son mantenidas, y DNUMBER no es un subconjunto de la clave de EMP_DEPT. Intuitivamente, podemos ver que la dependencia de DMGRSSN sobre DNUMBER es indeseable en EMP_DEPT dado que DNUMBER no es una clave de EMP_DEPT.</p>Bryanhttp://www.blogger.com/profile/05472394431987534865noreply@blogger.com1tag:blogger.com,1999:blog-3518817361276784656.post-72600385638416861112009-08-24T14:38:00.000-07:002009-08-24T14:40:25.693-07:00Ejemplo Tercera Forma Normal (3FN)<p style="margin-bottom: 0.0001pt; text-align: justify;"><span style="font-size: 12pt; font-family: "Times New Roman";">Para la Tercera Forma Normal (3NF) la relación debe estar en 2NF y además los atributos no clave deben ser mutuamente independientes y dependientes por completo de la clave primaria. También recordemos que dijimos que esto significa que las columnas en la tabla deben contener solamente información sobre la entidad definida por la clave primaria y, por tanto, las columnas en la tabla deben contener datos acerca de una sola cosa.</span></p><div style="text-align: justify;"> </div><p style="margin-bottom: 0.0001pt; text-align: justify;"><span style="font-size: 12pt; font-family: "Times New Roman";">En nuestro ejemplo en 2NF, la primera tabla conserva información acerca del libro, los autores y editoriales, por lo que debemos crear nuevas tablas para satisfacer los requisitos de 3NF.<o:p></o:p></span></p> <p style="margin-bottom: 0.0001pt;"><b><span style="font-size: 12pt; font-family: "Times New Roman";">3NF</span></b></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 142.5pt;" border="1" cellpadding="0" cellspacing="1" width="190"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="top" width="65"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLibro</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78pt;" valign="top" width="104"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Titulo</span><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1001</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78pt;" valign="top" width="104"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Variable compleja</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1004</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78pt;" valign="top" width="104"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Visual Basic 5</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1005</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78pt;" valign="top" width="104"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Estadística</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78pt;" valign="top" width="104"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">University</span></span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";"><span style=""> </span>1007</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 78pt;" valign="top" width="104"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Clipper</span></span><span style="font-family: "Times New Roman";"> 5.01</span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt; page-break-before: always;"><o:p> </o:p></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 138pt;" border="1" cellpadding="0" cellspacing="1" width="184"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="top" width="65"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodAutor</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.5pt;" valign="top" width="98"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Autor</span><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">801</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.5pt;" valign="top" width="98"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Murray</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Spiegel</span></span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">802</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.5pt;" valign="top" width="98"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">E. <span class="SpellE">Petroustsos</span></span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">803</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.5pt;" valign="top" width="98"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Nancy <span class="SpellE">Greenberg</span> </span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">804</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.5pt;" valign="top" width="98"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Priya</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Nathan</span></span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 48.75pt;" valign="bottom" width="65"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">806</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 73.5pt;" valign="top" width="98"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Ramalho</span></span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt;"><o:p> </o:p></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 134.25pt;" border="1" cellpadding="0" cellspacing="1" width="179"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 59.25pt;" valign="top" width="79"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodEditorial</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.25pt;" valign="top" width="79"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Editorial</span><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 59.25pt;" valign="bottom" width="79"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">901</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.25pt;" valign="top" width="79"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">McGraw</span></span><span style="font-family: "Times New Roman";"> Hill</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 59.25pt;" valign="bottom" width="79"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">902</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.25pt;" valign="top" width="79"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Anaya</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 59.25pt;" valign="bottom" width="79"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">903</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 59.25pt;" valign="top" width="79"> <p class="NormalWeb1"><span class="SpellE"><span style="font-family: "Times New Roman";">Oracle</span></span><span style="font-family: "Times New Roman";"> <span class="SpellE">Corp</span>.</span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt; text-align: justify;"><span style="font-size: 12pt; font-family: "Times New Roman";">Aunque hemos creado nuevas tablas para que cada una tenga sólo información acerca de una entidad, también hemos perdido la información acerca de qué autor ha escrito qué libro y las editoriales correspondientes, por lo que debemos crear otras tablas que relacionen cada libro con sus autores y editoriales.</span></p> <p style="margin-bottom: 0.0001pt;"><o:p> </o:p></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 112.5pt;" border="1" cellpadding="0" cellspacing="1" width="150"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54pt;" valign="top" width="72"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLibro</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.75pt;" valign="top" width="57"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">codAutor</span></b></span><b><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54pt;" valign="bottom" width="72"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1001</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.75pt;" valign="bottom" width="57"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">801</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54pt;" valign="bottom" width="72"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1004</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.75pt;" valign="bottom" width="57"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">802</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54pt;" valign="bottom" width="72"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1005</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.75pt;" valign="bottom" width="57"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">801</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54pt;" valign="bottom" width="72"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.75pt;" valign="bottom" width="57"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">803</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54pt;" valign="bottom" width="72"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.75pt;" valign="bottom" width="57"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">804</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54pt;" valign="bottom" width="72"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1007</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 42.75pt;" valign="bottom" width="57"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">806</span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt;"><o:p> </o:p></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 125.25pt;" border="1" cellpadding="0" cellspacing="1" width="167"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="top" width="73"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLibro</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="top" width="73"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">codEditorial</span></b></span><b><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1001</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">901</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1004</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">902</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1005</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">901</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">903</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1007</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 54.75pt;" valign="bottom" width="73"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">901</span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt;"><span style="font-size: 12pt; font-family: "Times New Roman";">Y el resto de las tablas no necesitan modificación.</span></p> <p style="margin-bottom: 0.0001pt;"><o:p> </o:p></p> <p style="margin-bottom: 0.0001pt; page-break-before: always;"><o:p> </o:p></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 186.75pt;" border="1" cellpadding="0" cellspacing="1" width="249"> <thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="top" width="61"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLector</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" valign="top" width="48"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Paterno</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" valign="top" width="49"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Materno</span><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="top" width="53"> <p class="NormalWeb2" style="text-align: center;" align="center"><b><span style="font-family: "Times New Roman";">Nombres</span><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="bottom" width="61"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">501</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" valign="top" width="48"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Pérez</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" valign="top" width="49"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Gómez</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="top" width="53"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Juan</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="bottom" width="61"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">502</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" valign="top" width="48"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Ríos </span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" valign="top" width="49"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Terán</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="top" width="53"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Ana</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="bottom" width="61"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">503</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" valign="top" width="48"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Roca</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" valign="top" width="49"> <p class="NormalWeb1"><o:p> </o:p></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="top" width="53"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">René</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 45.75pt;" valign="bottom" width="61"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">504</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36pt;" valign="top" width="48"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">García</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 36.75pt;" valign="top" width="49"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Roque</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="top" width="53"> <p class="NormalWeb1"><span style="font-family: "Times New Roman";">Luis</span></p> </td> </tr> </tbody></table> <p style="margin-bottom: 0.0001pt;"><o:p> </o:p></p> <table class="MsoNormalTable" style="border: 1pt outset black; width: 149.25pt; margin-left: 36pt;" border="1" cellpadding="0" cellspacing="1" width="199"><thead> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="top" width="53"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLibro</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 44.25pt;" valign="top" width="59"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">CodLector</span></b></span><b><o:p></o:p></b></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" valign="top" width="58"> <p class="NormalWeb2" style="text-align: center;" align="center"><span class="SpellE"><b><span style="font-family: "Times New Roman";">FechaDev</span></b></span><b><o:p></o:p></b></p> </td> </tr> </thead> <tbody><tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="bottom" width="53"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1001</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 44.25pt;" valign="bottom" width="59"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">501</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" valign="bottom" width="58"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">15/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="bottom" width="53"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1004</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 44.25pt;" valign="bottom" width="59"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">502</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" valign="bottom" width="58"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">17/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="bottom" width="53"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1005</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 44.25pt;" valign="bottom" width="59"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">503</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" valign="bottom" width="58"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">16/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="bottom" width="53"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1006</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 44.25pt;" valign="bottom" width="59"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">504</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" valign="bottom" width="58"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">20/04/2005</span></p> </td> </tr> <tr style=""> <td style="border: 1pt inset black; padding: 3pt; width: 39.75pt;" valign="bottom" width="53"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">1007</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 44.25pt;" valign="bottom" width="59"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">501</span></p> </td> <td style="border: 1pt inset black; padding: 3pt; width: 43.5pt;" valign="bottom" width="58"> <p class="NormalWeb1" style="text-align: right;" align="right"><span style="font-family: "Times New Roman";">18/04/2005</span></p></td></tr></tbody></table>Bryanhttp://www.blogger.com/profile/05472394431987534865noreply@blogger.com0