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From John English ...@brighton.ac.uk>
Subject Migrating CLOBs to new DB schema
Date Wed, 05 Jul 2006 22:56:56 GMT
I have a database where I need to change the schema for a couple of crucial
tables. This involves changing the types of some fields, so I can't just do
an "alter table". The tables contain CLOBs, so I can't use the provided SYSCS
export/import procedures. This is what I have tried so far:

* Dumping the data to a file using the output of an IJ select as the basis
   for the modified data and turning it into an insert statement. IJ barfs
   when the CLOB data is a string constant >32K in size.

* Creating new tables alongside the existing ones, using "insert from select"
   to populate them. The constraints are all wrong, I can't drop any tables
   because they depend on other tables via constraints, and it's really really
   horrible. I've also just realised why names for constraints are a good idea
   -- mine have none, so dropping them is not easy. I'm learning the hard way
   as usual.

Any other ideas that I could try?

  John English              | mailto:je@brighton.ac.uk
  Senior Lecturer           | http://www.it.bton.ac.uk/staff/je
  School of Computing & MIS | "Those who don't know their history
  University of Brighton    |  are condemned to relive it" (Santayana)

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