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From Oystein Grovlen - Sun Norway <Oystein.Grov...@Sun.COM>
Subject Re: CLOB data types in derby
Date Mon, 20 Aug 2007 11:06:21 GMT
Rahul Dwivedi wrote:
 > Hi,
 > Can some one help me to understand how CLOB is handled in derby my
 > questions are.
 > 1. If there are many tables in same table schema with CLOB column, and
 > my application try to copy data into other tables by using insert -
 > select statements,
 > does it copy the the CLOB data into other columns or is it some sort of
 > locator object that gets stored in tables without actually storing CLOB
 > data in multiple tables.

The CLOB data will be copied. I do not think Derby has any mechanism
for sharing columns between tables.

 > 2. Is there a way to verify the answer to question 1.?

1. You could check the files for the tables in the database directory.
    If the Clob is big, you should be able to detect whether it is
    stored twice or not.

2. You chould change the Clob (e.g., use Clob.setString) and see if
    the change has been made to both columns.


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