The Oracle (tm) Users' Co-Operative FAQ

How do I change the database block size ?


Author's name: Norman Dunbar

Author's Email: Oracle@bountifulsolutions.co.uk

Date written: 10/06/2001

Oracle version(s): 8.1.7

Because the database may have been created with a wrong sized block, there are times when the DBA may wish to change the block size. How does he/she do this ?

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The short, and unfortunate, answer is, you cannot.

The long answer is that you have to export the contents of the database, delete it and rebuild it with a new database block size as desired, then import everything again. Full step by step instructions are to be found in Note:1011167.7 on Metalink.

I believe that in Oracle 9i, there is an option to create tablespaces which have different block sizes - although I have not yet been able to confirm this on Metalink. There has been talk about this new feature on the news groups.


Further reading:

Ixora - why a large database block size

Note:1011167.7 How to change a database block size on Metalink - this will require a username and password to login. Registration is free, but you need to have a Service Access Code (SAC) number to register.


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