Oracle FAQ Your Portal to the Oracle Knowledge Grid

Home -> Community -> Mailing Lists -> Oracle-L -> Re: Rebuilding database to change block size

Re: Rebuilding database to change block size

From: Rachel Carmichael <>
Date: Tue, 06 Jun 2000 17:23:22 GMT
Message-Id: <>

Don't skip step 4.. you get errors if the controlfiles exist when you rebuild

7 -- I have a script to generate the create database commands, as well as the init.ora from an existing database. It's in the Annotated Archives, if you have it. Then edit to change what you want.

precreate only the tablespaces you want to change. Oracle will create the others as part of the import.

Oh, and save off any grants that sys has made that are not part of the Oracle-supplied scripts.... or you lose them


>From: "Miller, Jay" <>
>To: Multiple recipients of list ORACLE-L <>
>Subject: Rebuilding database to change block size
>Date: Tue, 06 Jun 2000 08:50:35 -0800
>Okay, we finally got enough storage space to hold an export of our
>datawarehouse so I'm going to change the block size from 4 to 16.
>Obviously I'm testing this on a small play database first, but I've never
>done this before so I have several questions and would welcome any
>advice/comments/criticisms. Here's what I was thinking of:
>1. Do a full export (consistent=y) as sys. Backup control file to trace
>(just as an extra precaution).
>2. Shutdown database.
>3. Cold backup of all files.
>4. Drop all datafiles,control files, redo logs. Any other cleanup
>necessary? Or since the CREATE DATABASE command will erase data in
>datafiles, can I just skip this step entirely?
>5. Change db_block_size in init.ora file
>6. Start database in NOMOUNT mode.
>Here's where I'm on somewhat thinner ice:
>7. Issue create database command. Is there a way to generate this
>automatically from the existing database? It's easy enough to write from
>scratch but I'd rather not take chances with typos if I don't have to.
>8. Change sys and system passwords.
>9. I definitely want to precreate a few tablespaces where I want to change
>the initial extent parameter. Is it necessary to precreate all tablespaces
>and users (I can generate that script very easily)?
>10. Import database as sys.
>Okay, what am I missing?
>Thanks to all,
>Author: Miller, Jay
>Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
>San Diego, California -- Public Internet access / Mailing Lists
>To REMOVE yourself from this mailing list, send an E-Mail message
>to: (note EXACT spelling of 'ListGuru') and in
>the message BODY, include a line containing: UNSUB ORACLE-L
>(or the name of mailing list you want to be removed from). You may
>also send the HELP command for other information (like subscribing).

Get Your Private, Free E-mail from MSN Hotmail at Received on Tue Jun 06 2000 - 12:23:22 CDT

Original text of this message