关于oracle的全文检索问题

请教给问题：做oracle的全文检索，将一个clob字段创建索引，数据量大概是40万条，初次创建索引的时候比较慢还可以忍受，但是同步和优化的时候也比较慢，请问有没有什么办法可以提高同步和优化的速度？

还没有做过用CLOB来作检索的例子，帮你顶一下。

示例


表结构：
create table products（
　　　　　　　　　 productid number（10） not null ，
　　　　　　　　　 name varchar2（255） ，
　　　　　　　　　 description CLOB） ；
　　方法：
SELECT productid， name FROM products
　　　　　　　 WHERE dbms_lob.instr（products.description，′some text′，1，1） > 0；

　　下面列出了DBMS_LOB包中的过程函数：

　 APPEND procedure Appends the contents of the source LOB to the destination LOB.
　　CLOSE procedure Closes a previously opened internal or external LOB.
　　COMPARE function Compares two entire LOBs or parts of two LOBs.
　　COPY procedure Copies all， or part， of the source LOB to the destination LOB.
　　CREATETEMPORARY procedure Creates a temporary BLOB or CLOB and its corresponding index in the user′s default temporary tablespace.
　　ERASE procedure Erases all or part of a LOB.
　　FILECLOSE procedure Closes the file.
　　FILECLOSEALL procedure Closes all previously opened files.
　　FILEEXISTS function Checks if the file exists on the server.
　　FILEGETNAME procedure Gets the directory alias and file name.
　　FILEISOPEN function Checks if the file was opened using the input BFILE locators.
　　FILEOPEN procedure Opens a file.
　　FREETEMPORARY procedure Frees the temporary BLOB or CLOB in the user′s default temporary tablespace.
　　GETCHUNKSIZE function Returns the amount of space used in the LOB chunk to store the LOB value.
　　GETLENGTH function Gets the length of the LOB value.
　　INSTR function Returns the matching position of the nth occurrence of the pattern in the LOB.
　　ISOPEN function Checks to see if the LOB was already opened using the input locator.
　　ISTEMPORARY function Checks if the locator is pointing to a temporary LOB.
　　LOADFROMFILE procedure Loads BFILE data into an internal LOB.
　　OPEN procedure Opens a LOB （internal， external， or temporary） in the indicated mode.
　　READ procedure Reads data from the LOB starting at the specified offset.
　　SUBSTR function Returns part of the LOB value starting at the specified offset.
　　TRIM procedure Trims the LOB value to the specified shorter length.
　　WRITE procedure Writes data to the LOB from a specified offset.
　　WRITEAPPEND procedure Writes a buffer to the end of a LOB.

我是不是没说清楚呀！！！
我要做的是索引分词，实现全文检索。

那就需要将blob的东东全部读出来  然后分词  搞成全文检索