How to create index

Question

In sql*plus i do as follows:
sql>create table xmltable(id number primary key,xml_text varchar2(2000));
sql>insert into xmltable values(1,'c:\temp\a1.xml');
sql>insert into xmltable values(2,'c:\temp\a2.xml');
sql>insert into xmltable values(3,'c:\temp\a3.xml');
The contents of file "a1.xml" located at directory "c:\temp" are:
<Order>
<tradeType>2</tradeType>
<tradeAmount>-2000.0</tradeAmount>
<webSiteCode>dangdang</webSiteCode>
<sellerCode>dangdang</sellerCode>
<orderNumber>A20021</orderNumber>
<tradeDate>2001-12-12</tradeDate>
<currencyType>156</currencyType>
</Order>
now if I want to create index what should I do?
I have created index in interMedia text manager (I don't know how to set the index options)
but when I executed the following statement:
sql>select id from xmltable
where contains(xml_text,'156 within currencyType')>0;
I find the error:ORA-20000: interMedia Text error: currencyType is not existed
why?????

Answer 1

In order to index XML files located in the file system, you have to define some indexing parameters. First, create a preference for the datastore type:
begin
ctx_ddl.create_preference('COMMON_DIR','FILE_DATASTORE');
ctx_ddl.set_attribute('COMMON_DIR','PATH','c:\temp');
end;
Then, define a XML section group, e.g.:
begin
ctx_ddl.create_section_group('XML_GROUP','xml_section_group');
ctx_ddl.add_zone_section('XML_GROUP', 'Order', 'Order');
ctx_ddl.add_zone_section('XML_GROUP', 'currencyType', 'currencyType');
end;
Now you can create the index:
create index myindex on xmltable(xml_text)
indextype is ctxsys.context
parameters ('datastore COMMON_DIR section group XML_GROUP');
Your select statement should work fine now. For more information about indexing, I recommend taking a look at the Oracle Text Reference.
Roman