oracle10g系统管理之表空间（三）

<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">1.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style="font-size: small;"><span style="">当建立表空间时，表空间及其所有数据文件都处于</span><span lang="EN-US"><span style="font-family: Times New Roman;">ONLINE</span></span><span style="">状态，此时该表空间及其数据文件是可以访问的；当表空间和数据文件处于</span><span lang="EN-US"><span style="font-family: Times New Roman;">OFFLINE</span></span><span style="">状态，表空间或其数据文件是不可访问的。维护表空间时，经常需要改变表空间的可用性。一把情况下，改变表空间可用性是由特权用户或</span><span lang="EN-US"><span style="font-family: Times New Roman;">DBA</span></span><span style="">完成的。如果其他用户想改变表空间的可用性，要求用户必须具有</span><span lang="EN-US"><span style="font-family: Times New Roman;">MANAGE TABLESPACE</span></span><span style="">系统权限</span><span lang="EN-US"><span style="font-family: Times New Roman;">.</span></span></span></p>
<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">2.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style="font-size: small;"><span style="">使表空间脱机</span><span lang="EN-US"><span style="font-family: Times New Roman;"> ALTER TABLESPACE tbs_8k OFFLINE;</span></span></span></p>
<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">3.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style="font-size: small;"><span style="">使用空间联机</span><span style="font-family: Times New Roman;"> <span lang="EN-US">ALTER TABLESPACE tbs_8k ONLINE;</span></span></span></p>
<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">4.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style="font-size: small;"><span style="">使数据文件脱机</span><span lang="EN-US"><span style="font-family: Times New Roman;"> ALTER DATABASE DATAFILE 3 OFFLINE</span></span><span style="">；</span></span></p>
<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">5.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style="font-size: small;"><span style="">使数据文件联机</span><span lang="EN-US"><span style="font-family: Times New Roman;"> ALTER DATABASE DATAFILE 3 ONLINE</span></span><span style="">；</span></span></p>
<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">6.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style=""><span style="font-size: small;">数据文件脱机，联机的场景是：当磁盘损坏导致数据文件丢失时，如果要打开数据库，控制文件将无法定位需要打开的数据文件。此时，需要使数据文件脱机，以快速打开数据库。当数据文件恢复后，可以使数据文件联机。</span></span></p>
<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">7.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style=""><span style="font-size: small;">改变表空间的读写状态：普通的表空间是允许读写的。但是如果某一个表空间里所有数据都是静态数据，为了便于管理和备份，可以讲表空间转变为只读状态。另外如果要把表空间搬移到其他数据库，在搬移之前必须将表空间变为只读状态。</span></span></p>
<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">8.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style="font-size: small;"><span style="">使表空间只读</span><span lang="EN-US"><span style="font-family: Times New Roman;"><span style=""> </span>ALTER TABLESAPCE tbs_8k READ ONLY;</span></span><span style="">表空间变为只读之后，数据库用户只能在该表空间上执行查询操作，不能进行</span><span lang="EN-US"><span style="font-family: Times New Roman;">DML</span></span><span style="">和</span><span lang="EN-US"><span style="font-family: Times New Roman;">DDL</span></span><span style="">操作。但是可以执行</span><span lang="EN-US"><span style="font-family: Times New Roman;">DROP</span></span><span style="">操作。</span></span></p>
<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">9.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style="font-size: small;"><span style="">使表空间可写</span><span lang="EN-US"><span style="font-family: Times New Roman;"> ALTER TABLESPACE tbs_8k READ WRITE;</span></span></span></p>
<p class="MsoNormal" style=""><span style="" lang="EN-US"><span style=""><span style="font-family: Times New Roman;"><span style="font-size: small;">10.</span><span style='font: 7pt "Times New Roman";'> </span></span></span></span><span style="font-size: small;"><span style="">改变表空间名称</span><span style="font-family: Times New Roman;"> <span lang="EN-US">ALTER TABLESPACE tbs_8k RENAME TO tb_8k;</span></span></span></p>