Re: DB_FILE_MULTIBLOCK_READ_COUNT

Kevin--
I tried the procedure below for the first time this weekend, and for the record it worked great. However, portions of it are still running; I had two tables with LONG columns, and these imports failed because my buffer size was too small. As was recommended in the docs, I increased the buffer size by powers of 2 until it was big enough to work, which is fine but slow. I may be asking too much, even of Oracle, but is there a way to globally estimate the buffer size using a query, e.g. tell me the length of the longest LONG in tables that have them?
--Russ

Kevin Loney wrote:

> Mark G. Woodruff wrote in message <714uin$nnq$1_at_comet2.magicnet.net>...
> >>Your block size is low; for a production application you should be at 4K.
> >>Instant 40% performance improvement - after you do the full rebuild that
> requires.
> >
> >A newbiew question: how would I do such a full rebuild? Do I just run
> >orainst again and tell it to create the database objects again?
> >
>
> For an existing database:
> 1. Export the full database, being sure to get all rows, constraints,
> indexes, and grants.
> 2. Verify that the export works by doing a test export into a different
> database.
> 3. If the data is critical, do a file system backup of the database while
> the database is down.
> 4. Delete the database files - all data files, control files, redo logs.
> If you're squeamish about this and have the disk space to spare, then move
> them to different locations instead of deleting them.
> 5. Re-run your CREATE DATABASE scripts. The Oracle installer creates these
> (depending on the db version). For Oracle8, check in
> /app/oracle/admin/<instancename>/scripts
> 6. Once the database has been created, use the Export file from step 1 to
> Import the full database. Depending on the size of the database, this may
> take awhile.
>
> hth.
> Kevin.
> http://www.kevinloney.com
Received on Mon Nov 02 1998 - 22:27:57 CST