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dbca创建数据库不同模板之间的区别

原创 作者:尛样儿 时间:2015-07-27 23:56:40 0 删除 编辑
<br /> &nbsp;<span style="font-size:16px;font-family:'Courier New';"> &nbsp; 这篇文章讨论通过dbca创建数据库,默认模板之间的区别,下面是11.2.0.3 dbca建库选择模板的截图:<br /> </span><br /> <img src="/attachment/201507/27/23135684_14380107739T3P.jpg" width="700" height="500.656167979" alt="" /><span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';">&nbsp; &nbsp;&nbsp;从截图可以看出,系统自带3个模板,分别是:“一般用途和事务处理</span><span style="font-size:16px;font-family:'Courier New';">”,“定制数据库</span><span style="font-size:16px;font-family:'Courier New';">”,“数据仓库</span><span style="font-size:16px;font-family:'Courier New';">”,之前的Oracle Database版本好像是4个模板,一般用途和事务处理是不同的两个模板。</span><br /> <br /> <span style="font-size:16px;font-family:'Courier New';"></span><span style="font-size:16px;font-family:'Courier New';">下面我们看看Oracle是怎么解释系统自带模板的:</span><br /> <span style="font-size:16px;font-family:'Courier New';"></span> <p style="font-family:Tahoma, sans-serif;font-size:small;line-height:normal;white-space:normal;widows:auto;background-color:#FFFFFF;"> <span style="font-size:16px;font-family:'Courier New';">Templates are divided into the following types:</span> </p> <ul style="font-family:Tahoma, sans-serif;font-size:small;line-height:normal;white-space:normal;widows:auto;background-color:#FFFFFF;"> <li> <p> <span style="font-size:16px;font-family:'Courier New';">Seed templates</span> </p> </li> <li> <p> <span style="font-size:16px;font-family:'Courier New';">Nonseed templates</span> </p> </li> </ul> <p style="font-family:Tahoma, sans-serif;font-size:small;line-height:normal;white-space:normal;widows:auto;background-color:#FFFFFF;"> <span style="font-size:16px;font-family:'Courier New';">The characteristics of each are shown in&nbsp;</span><a href="http://docs.oracle.com/cd/E25054_01/server.1111/e10897/install.htm#BABJJIIG" style="color:#72007C;background-image:inherit;background-size:inherit;background-attachment:inherit;background-origin:inherit;background-clip:inherit;background-color:inherit;background-position:inherit inherit;background-repeat:inherit inherit;"><span style="font-size:16px;font-family:'Courier New';">Table 2-1</span></a><span style="font-size:16px;font-family:'Courier New';">.</span> </p> <div class="tblruleformalwide" style="font-family:Tahoma, sans-serif;font-size:small;line-height:normal;white-space:normal;widows:auto;background-color:#FFFFFF;"> <br /> <p class="titleintable" style="font-weight:bold;font-style:italic;"> <span style="font-size:16px;font-family:'Courier New';">Table 2-1 DBCA Template Types</span> </p> <table class="RuleFormalWide" title="DBCA Template Types" summary="This table describes the DBCA template types." dir="ltr" border="1" width="100%" frame="border" rules="all" cellpadding="3" cellspacing="0" style="font-size:small;"> <colgroup><col width="12%" /><col width="12%" /><col width="12%" /><col width="*" /></colgroup> <thead> <tr align="left" valign="top"> <th align="left" valign="bottom" id="r1c1-t13" style="vertical-align:bottom;"> <span style="font-size:16px;font-family:'Courier New';">Type</span> </th> <th align="left" valign="bottom" id="r1c2-t13" style="vertical-align:bottom;"> <span style="font-size:16px;font-family:'Courier New';">File Extension</span> </th> <th align="left" valign="bottom" id="r1c3-t13" style="vertical-align:bottom;"> <span style="font-size:16px;font-family:'Courier New';">Includes Data Files</span> </th> <th align="left" valign="bottom" id="r1c4-t13" style="vertical-align:bottom;"> <span style="font-size:16px;font-family:'Courier New';">Database Structure</span> </th> </tr> </thead> <tbody> <tr align="left" valign="top"> <td align="left" id="r2c1-t13" headers="r1c1-t13" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Seed</span> </p> </td> <td align="left" headers="r2c1-t13 r1c2-t13" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <code><span style="font-size:16px;font-family:'Courier New';">.dbc</span></code> </p> </td> <td align="left" headers="r2c1-t13 r1c3-t13" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Yes</span> </p> </td> <td align="left" headers="r2c1-t13 r1c4-t13" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">This type of template contains both the structure and the physical data files of an existing database, referred to as the&nbsp;</span><span class="italic" style="font-style:italic;font-size:16px;font-family:'Courier New';">seed database</span><span style="font-size:16px;font-family:'Courier New';">. Your new database starts as a copy of the seed database, and requires only the following changes:</span> </p> <ul> <li> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Name of the database</span> </p> </li> <li> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Destination of the data files</span> </p> </li> <li> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Number of control files</span> </p> </li> <li> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Number of online redo log groups</span> </p> </li> <li> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Initialization parameters</span> </p> </li> </ul> <p> <span style="font-size:16px;font-family:'Courier New';">Other changes can be made after database creation using custom scripts that can be invoked by DBCA, command-line SQL statements, or Oracle Enterprise Manager Database Control.</span> </p> <p> <span style="font-size:16px;font-family:'Courier New';">The data files for the seed database are stored in compressed RMAN backup format in a file with a .dfb extension. The seed database control file is stored in a file with .ctl extension. (This file is needed only when storing data files in Oracle Automatic Storage Management (Oracle ASM) disk groups or as Oracle Managed Files.) The .dbc file contains the location of the seed database data files and contains the source database name used to mount the control file.</span> </p> </td> </tr> <tr align="left" valign="top"> <td align="left" id="r3c1-t13" headers="r1c1-t13" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Nonseed</span> </p> </td> <td align="left" headers="r3c1-t13 r1c2-t13" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <code><span style="font-size:16px;font-family:'Courier New';">.dbt</span></code> </p> </td> <td align="left" headers="r3c1-t13 r1c3-t13" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">No</span> </p> </td> <td align="left" headers="r3c1-t13 r1c4-t13" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">This type of template is used to create a new database. It contains the characteristics of the database to be created. Nonseed templates are more flexible than their seed counterparts because all data files and online redo log files are created to your specification, and names, sizes, and other attributes can be changed as required.</span> </p> <div> <br /> </div> </td> </tr> </tbody> </table> </div> <span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';"></span><span style="font-size:16px;font-family:'Courier New';"></span><span style="font-size:16px;font-family:'Courier New';">&nbsp; &nbsp; Oracle将模板类型分为seed和Nonseed模板,上图中的“包含数据文件</span><span style="font-size:16px;font-family:'Courier New';">”为“是</span><span style="font-size:16px;font-family:'Courier New';">”的就是seed模板类型,它的特点是包含数据文件,简单的说就是从一个RMAN备份中恢复数据库,由于是恢复数据库不能设定数据文件大小,不能设定选件等,最大特点是创建速度特别快,</span><span style="white-space:normal;font-size:16px;font-family:'Courier New';">“一般用途和事务处理</span><span style="white-space:normal;"><span style="font-size:16px;font-family:'Courier New';">”和“数据仓库</span><span style="font-size:16px;font-family:'Courier New';">”就属于这种模板类型;“定制</span><span style="font-size:16px;font-family:'Courier New';">数据库</span><span style="font-size:16px;font-family:'Courier New';">”属于Nonseed模板,</span></span><span style="font-size:16px;font-family:'Courier New';">该模板不包含数据文件,需要使用create database命令创建数据库,创建周期较长,但能根据需要选择组件,控制数据文件大小等,更加的灵活,但对于大部分系统业务来说,“一般用途和事务处理</span><span style="font-size:16px;font-family:'Courier New';">”模板类型是最常用的选择。</span><br /> <span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';"> &nbsp; &nbsp;刚刚我们已经提到,</span><span style="white-space:normal;font-size:16px;font-family:'Courier New';">“一般用途和事务处理</span><span style="white-space:normal;"><span style="font-size:16px;font-family:'Courier New';">”和“数据仓库”都是从同一个模板(备份)类型的文件中恢复而来,Oracle的模板存放位置为$ORACLE_HOME</span><span style="font-size:16px;font-family:'Courier New';">\assistants\dbca\templates,下面是模板位置下的文件截图:</span><br /> <span style="font-size:16px;font-family:'Courier New';"></span><img src="/attachment/201507/27/23135684_1438011290Hp9V.jpg" width="589" height="167" alt="" /><span style="font-size:16px;font-family:'Courier New';"></span></span><span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';">&nbsp; &nbsp; example.dmp和example01.dfb是“示例表空间”的内容,可以猜想是通过可传输表空间的形式附加到创建的数据库中。</span><br /> <span style="font-size:16px;font-family:'Courier New';"> &nbsp; &nbsp;Data_Warehouse.dbc是</span><span style="white-space:normal;font-size:16px;font-family:'Courier New';">“数据仓库</span><span style="white-space:normal;"><span style="font-size:16px;font-family:'Courier New';">”模板文件,General_purpose.dbc是“</span><span style="white-space:normal;font-size:16px;font-family:'Courier New';">一般用途和事务处理</span><span style="font-size:16px;font-family:'Courier New';"></span><span style="font-size:16px;font-family:'Courier New';">”模板文件</span></span><span style="font-size:16px;font-family:'Courier New';">,它们都属于Seed模板类型,对应同一个模板文件Seed_Database.dfb,Seed_Database.ctl是seed数据库的控制文件(从这点再次印证控制文件对于RMAN恢复的重要性)</span><span style="font-size:16px;font-family:'Courier New';">。</span><br /> <span style="font-size:16px;font-family:'Courier New';"> &nbsp; &nbsp;New_Database.dbt是Nonseed模板文件,属于不包含数据文件的模板,*.dbc和*.dbt都是以XML文件的形式进行存储</span><span style="font-size:16px;font-family:'Courier New';">。</span><br /> <span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';">&nbsp; &nbsp; 既然</span><span style="font-size:16px;font-family:'Courier New';"></span><span style="white-space:normal;font-size:16px;font-family:'Courier New';">“一般用途和事务处理</span><span style="white-space:normal;"><span style="font-size:16px;font-family:'Courier New';">”和“数据仓库”都属于seed模板类型,那么它们之间又有什么区别呢?下面首先来看看Oracle对它们的解释:</span><br /> <h4 class="sect3" id="autoId29" style="font-size:16px;font-family:Tahoma, sans-serif;line-height:normal;white-space:normal;widows:auto;background-color:#FFFFFF;"> <span style="font-size:16px;font-family:'Courier New';">DBCA Templates Provided by Oracle</span> </h4> <p style="font-family:Tahoma, sans-serif;font-size:small;line-height:normal;white-space:normal;widows:auto;background-color:#FFFFFF;"> <span style="font-size:16px;font-family:'Courier New';">Oracle provides the templates shown in&nbsp;</span><a href="http://docs.oracle.com/cd/E25054_01/server.1111/e10897/install.htm#BABHDEDA" style="color:#72007C;background-image:inherit;background-size:inherit;background-attachment:inherit;background-origin:inherit;background-clip:inherit;background-color:inherit;background-position:inherit inherit;background-repeat:inherit inherit;"><span style="font-size:16px;font-family:'Courier New';">Table 2-2</span></a><span style="font-size:16px;font-family:'Courier New';">.</span> </p> <div class="tblruleformal" style="font-family:Tahoma, sans-serif;font-size:small;line-height:normal;white-space:normal;widows:auto;background-color:#FFFFFF;"> <br /> <p class="titleintable" style="font-weight:bold;font-style:italic;"> <span style="font-size:16px;font-family:'Courier New';">Table 2-2 Oracle-Provided DBCA Templates and Their Corresponding Workloads</span> </p> <table class="RuleFormal" title="Oracle-Provided DBCA Templates and Their Corresponding Workloads" summary="This table describes the DBCA template environments." dir="ltr" border="1" width="100%" frame="border" rules="all" cellpadding="3" cellspacing="0" style="font-size:small;"> <colgroup><col width="27%" /><col width="*" /></colgroup> <thead> <tr align="left" valign="top"> <th align="left" valign="bottom" id="r1c1-t14" style="vertical-align:bottom;"> <span style="font-size:16px;font-family:'Courier New';">Template</span> </th> <th align="left" valign="bottom" id="r1c2-t14" style="vertical-align:bottom;"> <span style="font-size:16px;font-family:'Courier New';">Workload</span> </th> </tr> </thead> <tbody> <tr align="left" valign="top"> <td align="left" id="r2c1-t14" headers="r1c1-t14" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Data warehouse</span> </p> </td> <td align="left" headers="r2c1-t14 r1c2-t14" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Users perform numerous, complex queries that process large volumes of data. Response time, accuracy, and availability are key issues.</span> </p> <p> <span style="font-size:16px;font-family:'Courier New';">These queries (</span><code><span style="font-size:16px;font-family:'Courier New';">SELECT</span></code><span style="font-size:16px;font-family:'Courier New';">&nbsp;statements) range from a fetch of a few records to queries that sort thousands of records from many different tables.</span> </p> </td> </tr> <tr align="left" valign="top"> <td align="left" id="r3c1-t14" headers="r1c1-t14" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">General Purpose or Transaction processing</span> </p> </td> <td align="left" headers="r3c1-t14 r1c2-t14" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Many concurrent users perform numerous transactions that require rapid access to data. Availability, speed, concurrency, and recoverability are key issues.</span> </p> <p> <span style="font-size:16px;font-family:'Courier New';">Transactions consist of reading (</span><code><span style="font-size:16px;font-family:'Courier New';">SELECT</span></code><span style="font-size:16px;font-family:'Courier New';">&nbsp;statements), writing (</span><code><span style="font-size:16px;font-family:'Courier New';">INSERT</span></code><span style="font-size:16px;font-family:'Courier New';">&nbsp;and&nbsp;</span><code><span style="font-size:16px;font-family:'Courier New';">UPDATE</span></code><span style="font-size:16px;font-family:'Courier New';">&nbsp;statements), and deleting (</span><code><span style="font-size:16px;font-family:'Courier New';">DELETE</span></code><span style="font-size:16px;font-family:'Courier New';">&nbsp;statements) data in database tables.</span> </p> </td> </tr> <tr align="left" valign="top"> <td align="left" id="r4c1-t14" headers="r1c1-t14" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">Custom database</span> </p> </td> <td align="left" headers="r4c1-t14 r1c2-t14" style="vertical-align:top;"> <p style="margin-top:0px;margin-bottom:0px;"> <span style="font-size:16px;font-family:'Courier New';">This template allows you maximum flexibility in defining a database because you can change any of the settings for the database being created.</span> </p> <div> <br /> </div> </td> </tr> </tbody> </table> </div> <span style="font-size:16px;font-family:'Courier New';"></span></span><span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';"> &nbsp; &nbsp;Oracle只在用途上对它们进行了解释,除此之外,我们来对比一下两个模板dbc文件之间的区别:</span><br /> <span style="font-size:16px;font-family:'Courier New';">用文件比较文件可以很容易的发现,Data_Warehouse.dbc比General_Purpose.dbc文件多了下面这行:</span><br /> <span style="font-size:16px;font-family:'Courier New';"></span><span style="font-size:16px;font-family:'Courier New';">&lt;initParam name="star_transformation_enabled" value="TRUE"/&gt;</span><span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';">这是一个初始化参数,下面是对它的解释:</span><br /> <h1 class="sect1" style="box-sizing:border-box;margin:1em 0px 15px;padding:0px;font-family:Arial, sans-serif;font-weight:500;color:#4F4F4F;text-rendering:optimizelegibility;line-height:1.2;font-size:36px;white-space:normal;widows:auto;background-color:#FFFFFF;"> STAR_TRANSFORMATION_ENABLED<a id="sthref696" style="box-sizing:border-box;color:#1D5AAB;line-height:inherit;"></a><a id="sthref697" style="box-sizing:border-box;color:#1D5AAB;line-height:inherit;"></a> </h1> <div class="inftblinformal" style="box-sizing:border-box;margin:0px;padding:0px;max-width:90em;color:#222222;font-family:'Helvetica Neue', 'Neue Helvetica', Arial, sans-serif;font-size:14px;line-height:21px;white-space:normal;widows:auto;background-color:#FFFFFF;"> <table class="cellalignment1658" title="STAR_TRANSFORMATION_ENABLED initialization parameter" summary="This table is described in the preceding text" style="box-sizing:border-box;margin-bottom:1.25rem;border:none;table-layout:fixed;width:1006px;border-spacing:0px;padding:3px;max-width:90em;"> <thead style="box-sizing:border-box;background-color:#F5F5F5;background-position:initial initial;background-repeat:initial initial;"> <tr class="cellalignment1652" style="box-sizing:border-box;vertical-align:top;background-color:#3F3F3F !important;"> <th class="cellalignment1659" id="r1c1-t458" style="box-sizing:border-box;margin:0px;padding:0.5rem 0.625rem 0.625rem;color:#222222;font-size:0.875rem;line-height:1.125rem;vertical-align:bottom;"> Property </th> <th class="cellalignment1659" id="r1c2-t458" style="box-sizing:border-box;margin:0px;padding:0.5rem 0.625rem 0.625rem;color:#222222;font-size:0.875rem;line-height:1.125rem;vertical-align:bottom;"> Description </th> </tr> </thead> <tbody style="box-sizing:border-box;"> <tr class="cellalignment1652" style="box-sizing:border-box;vertical-align:top;padding:8px 6px;border-bottom-width:1px;border-bottom-style:solid;border-bottom-color:#3F3F3F;"> <td class="cellalignment1660" id="r2c1-t458" headers="r1c1-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> <span class="bold" style="box-sizing:border-box;">Parameter type</span> </td> <td class="cellalignment1660" headers="r2c1-t458 r1c2-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> String </td> </tr> <tr class="cellalignment1652" style="box-sizing:border-box;vertical-align:top;padding:8px 6px;border-bottom-width:1px;border-bottom-style:solid;border-bottom-color:#3F3F3F;background-color:#F9F9F9;"> <td class="cellalignment1660" id="r3c1-t458" headers="r1c1-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> <span class="bold" style="box-sizing:border-box;">Syntax</span> </td> <td class="cellalignment1660" headers="r3c1-t458 r1c2-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> <code style="box-sizing:border-box;font-family:menlo, monaco, 'Courier New', Courier, mono, serif;font-size:13px;color:#000000;line-height:1.615;padding:3px 5px;font-weight:bold;background-color:#EEEEEE;">STAR_TRANSFORMATION_ENABLED = { FALSE | TRUE | TEMP_DISABLE }</code> </td> </tr> <tr class="cellalignment1652" style="box-sizing:border-box;vertical-align:top;padding:8px 6px;border-bottom-width:1px;border-bottom-style:solid;border-bottom-color:#3F3F3F;"> <td class="cellalignment1660" id="r4c1-t458" headers="r1c1-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> <span class="bold" style="box-sizing:border-box;">Default value</span> </td> <td class="cellalignment1660" headers="r4c1-t458 r1c2-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> <code style="box-sizing:border-box;font-family:menlo, monaco, 'Courier New', Courier, mono, serif;font-size:13px;color:#000000;line-height:1.615;padding:3px 5px;font-weight:bold;background-color:#EEEEEE;">FALSE</code> </td> </tr> <tr class="cellalignment1652" style="box-sizing:border-box;vertical-align:top;padding:8px 6px;border-bottom-width:1px;border-bottom-style:solid;border-bottom-color:#3F3F3F;background-color:#F9F9F9;"> <td class="cellalignment1660" id="r5c1-t458" headers="r1c1-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> <span class="bold" style="box-sizing:border-box;">Modifiable</span> </td> <td class="cellalignment1660" headers="r5c1-t458 r1c2-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> <code style="box-sizing:border-box;font-family:menlo, monaco, 'Courier New', Courier, mono, serif;font-size:13px;color:#000000;line-height:1.615;padding:3px 5px;font-weight:bold;background-color:#EEEEEE;">ALTER SESSION</code>,&nbsp;<code style="box-sizing:border-box;font-family:menlo, monaco, 'Courier New', Courier, mono, serif;font-size:13px;color:#000000;line-height:1.615;padding:3px 5px;font-weight:bold;background-color:#EEEEEE;">ALTER SYSTEM</code> </td> </tr> <tr class="cellalignment1652" style="box-sizing:border-box;vertical-align:top;padding:8px 6px;border-bottom-width:2px !important;border-bottom-style:solid !important;border-bottom-color:#3F3F3F !important;"> <td class="cellalignment1660" id="r6c1-t458" headers="r1c1-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> <span class="bold" style="box-sizing:border-box;">Basic</span> </td> <td class="cellalignment1660" headers="r6c1-t458 r1c2-t458" style="box-sizing:border-box;margin:0px;padding:0.5625rem 0.625rem;font-size:0.875rem;color:#222222;line-height:1.125rem;"> Yes </td> </tr> </tbody> </table> <br style="box-sizing:border-box;" /> </div> <p style="box-sizing:border-box;margin-top:0px;margin-bottom:1.25rem;font-family:'Helvetica Neue', 'Neue Helvetica', Arial, sans-serif;font-size:14px;line-height:1.4;text-rendering:optimizelegibility;max-width:90em;color:#222222;white-space:normal;widows:auto;background-color:#FFFFFF;"> <code style="box-sizing:border-box;font-family:menlo, monaco, 'Courier New', Courier, mono, serif;font-size:13px;color:#000000;line-height:1.615;padding:3px 5px;font-weight:bold;background-color:#EEEEEE;">STAR_TRANSFORMATION_ENABLED</code>&nbsp;determines whether a cost-based query transformation will be applied to star queries. </p> <p style="box-sizing:border-box;margin-top:0px;margin-bottom:1.25rem;font-family:'Helvetica Neue', 'Neue Helvetica', Arial, sans-serif;font-size:14px;line-height:1.4;text-rendering:optimizelegibility;max-width:90em;color:#222222;white-space:normal;widows:auto;background-color:#FFFFFF;"> <span class="bold" style="box-sizing:border-box;">Values:</span> </p> <ul style="box-sizing:border-box;margin:0px 0px 1.25rem 35px;padding:10px 0px 10px 10px;font-size:14px;line-height:1.6;list-style-position:outside;font-family:'Helvetica Neue', 'Neue Helvetica', Arial, sans-serif;color:#222222;white-space:normal;widows:auto;background-color:#FFFFFF;"> <li style="box-sizing:border-box;margin:10px 0px 20px;padding:0px;"> <p style="box-sizing:border-box;margin-top:0px;margin-bottom:1.25rem;font-family:inherit;line-height:1.4;text-rendering:optimizelegibility;max-width:90em;"> <code style="box-sizing:border-box;font-family:menlo, monaco, 'Courier New', Courier, mono, serif;font-size:13px;color:#000000;line-height:1.615;padding:3px 5px;font-weight:bold;background-color:#EEEEEE;">FALSE</code> </p> <p style="box-sizing:border-box;margin-top:0px;margin-bottom:1.25rem;font-family:inherit;line-height:1.4;text-rendering:optimizelegibility;max-width:90em;"> The transformation will not be applied. </p> </li> <li style="box-sizing:border-box;margin:10px 0px 20px;padding:0px;"> <p style="box-sizing:border-box;margin-top:0px;margin-bottom:1.25rem;font-family:inherit;line-height:1.4;text-rendering:optimizelegibility;max-width:90em;"> <code style="box-sizing:border-box;font-family:menlo, monaco, 'Courier New', Courier, mono, serif;font-size:13px;color:#000000;line-height:1.615;padding:3px 5px;font-weight:bold;background-color:#EEEEEE;">TRUE</code> </p> <p style="box-sizing:border-box;margin-top:0px;margin-bottom:1.25rem;font-family:inherit;line-height:1.4;text-rendering:optimizelegibility;max-width:90em;"> The optimizer will consider performing a cost-based query transformation on the star query. </p> </li> <li style="box-sizing:border-box;margin:10px 0px 20px;padding:0px;"> <p style="box-sizing:border-box;margin-top:0px;margin-bottom:1.25rem;font-family:inherit;line-height:1.4;text-rendering:optimizelegibility;max-width:90em;"> <code style="box-sizing:border-box;font-family:menlo, monaco, 'Courier New', Courier, mono, serif;font-size:13px;color:#000000;line-height:1.615;padding:3px 5px;font-weight:bold;background-color:#EEEEEE;">TEMP_DISABLE</code> </p> <p style="box-sizing:border-box;margin-top:0px;margin-bottom:1.25rem;font-family:inherit;line-height:1.4;text-rendering:optimizelegibility;max-width:90em;"> The optimizer will consider performing a cost-based query transformation on the star query but will not use temporary tables in the star transformation. </p> </li> </ul> <span style="font-size:16px;font-family:'Courier New';">这是启用数据仓库中的星形模式,相关的知识可以搜索一下,</span><span style="font-size:16px;font-family:'Courier New';">其他区别还未发现,等待我们去发现。</span><span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';"></span><br /> <span style="font-size:16px;font-family:'Courier New';">--end--</span><br /> <span style="font-size:16px;font-family:'Courier New';"></span>
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Oracle数据库管理员,Oracle数据库系统构架员;2012年7月出版《构建最高可用Oracle数据库系统:Oracle 11gR2 RAC管理、维护与性能优化》一书;Oracle 10g OCM。

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