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Oracle Text Contains Problem

Posted on 2009-06-30
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Last Modified: 2013-12-19
Hi Everyone,
I'm using the Oracle Text contains function, but it sometimes doesn't work properly.  It returns 0 (text not found) when the text is actually there.

For example:

select e.* , contains(e.emp_name, '%Jones%') as cont_val
from emp_table e
where e.emp_name = 'Jones'

Returns a row with cont_val = 0 (which means text not found).  Results for %Jones% in the contains function in the where clause return no rows.  This is a sporadic problem that only occurs for some rows in our table.  We're using Oracle 10.2.0.1.0.
Any ideas what's going on?
Thanks

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Question by:leclaude
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by:mrjoltcola
ID: 24828838
How are you updating your text indexes? They are not immediately synched and must be maintained, unlike regular indexes.

http://download.oracle.com/docs/cd/B15595_01/content.101/b14493/text.htm#sthref776

See the docs on ctx_ddl.sync_index() for manually synching, try a manual sync and see if it shows.

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by:leclaude
ID: 24903920
Why would an index need to be synched to return a row? At worst the query should be slow, but not miss results.
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Accepted Solution

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mrjoltcola earned 2000 total points
ID: 24906622
That is how text indexes work. Text indexes are not standard Oracle b-tree indexes. The update does not happen immediately upon insert or update of the rows. Instead the change is scheduled, and will be applied when the next sync is run. In 10g and 11g I believe there is a setting that forces immediate update but it is poor for performance.

Please read this for an explanation:

http://www.oracle.com/technology/products/text/htdocs/Index_Maintenance.html
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