how to modify db_block_size

[chikkodi]

Hi,

how can we modify db_block_size after creating the database ?

I tried doing this:
edit init.ora
modify db_block_size
shutdown db
startup db

now its giving me an error "control file mismatch for db_block_size"

please help.
Also, how can we determine the appropriate value for db_block_size ?
The default is 8k

Thanks in advance

[ac]

To change the db_block_size you have to re-create the database.

The size depends on the type of database... OLTP or DSS.

Smaller size for OLTP and large for DSS

[nabaig]

There is no way to change DB_BLOCK_SIZE without recreating the database.

Nizar

[kmesser]

It's not true that you can't do it. You just can't do it through the init.ora alone. In one of my Oracle Education courses, the instructor (who was excellent - knowledgeable and experienced), told us it could be done - unsupported. Oracle does not support changing DB_BLOCK_SIZE for an existing DB.

Search around. There's info out there about how to do this. If I find it, I'll share it.