Re: IMP/EXP accross platforms: What will be missing?

From: Rick Denoire <100.17706_at_germanynet.de>
Date: Tue, 04 Nov 2003 23:45:21 +0100
Message-ID: <cj8gqvcrc2baggf6bclli9jbv8sq1fk51k@4ax.com>

"Burt Peltier" <burttemp1ReMoVeThIs_at_bellsouth.net> wrote:

>Have you ever done a full export to disk ?
Used to do it every day. Now only once a week (too time consuming).

>- Export to a named pipe and route output of pipe to compress and route
>output of compress to disk. You might be surprised at how much it gets
>compressed to. There are probably examples in Google search and in Metalink,
>if you haven't done this yet.

Exports go to pipe and get compressed routinely at our site. Compression factor is about 30 fold. Otherwise we would have big trouble... Handling uncompressed full exports is not feasible with this DB size.

For this transfer I am planning, it is still a bit more of named pipes:

a)export to a pipe1
b)gzip reads from pipe1, writes compressed file to pipe2
c)a copy process (rcp, rsync, cp via nfs, still don't know) reads from

pipe2 and sends to a file on remote host, where: d)gunzip reads from this file and decompresses into a pipe 3 e)import reads from pipe3 into the DB.

Funny, right?

>Db links are always fun and Plsql and views . It seems there is always at
>least 1 or 2 that are invalid or become invalid.

DB links will be set up as a last step. I am afraid that a DB link could be used unintentionally and cause a desaster. And I will announce to "kill" everything that is invalid in the source DB prior to this operation. Compile or die.

I have had the case where one or two indexes were missing, just missing. I would say: "This process is inmanent unreliable - don't let your life depend on it".

I don't think that imp/exp is an appropriate tool to do this transfer, but the only alternative would be "create table .. as select * from...[table on source DB]" (over the network) which is more flexible that imp/exp, but is essentially a "manual" procedure where the DBA must take care of every single step -> More chances for Murphy.

Rick Denoire Received on Tue Nov 04 2003 - 16:45:21 CST