Re: Importing on Linux is SO SLOW.

"Charles J. Fisher" wrote:
>
> I haven't had time for adequate performance-testing yet, but attempting to
> move a Siebel schema from HPUX 10.20/Oracle 8.0.5 to SUSE Linux/Oracle
> 8.1.7 is taking FOREVER - the export piped to gzip took a little over
> three hours, but the import has now taken over a day and it's only 1/3
> done.

Probably your have exported all indexes. This is correct but means that after importing table data the instance has to calculate the index segments which can cost a lot.

You could monitor this by select count(*) from the most recently imported table. If it doesn_t change after a while, an index is calculated.

Next time you should run "imp feedback=1000 commit=y".

>
> Would setting "AUTOEXTEND ON" for the datafiles slow things down? I had a
> reasonably fast import of the development data, but it was smaller.

Autoextend ON is almost always a bad idea, especially without a maximum clause. But it shouldn't slow down the import that much.

>
> Also, if I do a full import to Linux, do I have to rerun catalog.sql and
> catproc.sql?

If it is a FULL export on the 8.0.5, it would be better.

>
> Sizes:
>
> prdcrm2:/home/oracle # gzip -l devcrm.exp.gz siebel.exp.gz
> compressed uncompressed ratio uncompressed_name
> 53529593 627102720 91.4% devcrm.exp
> 279769621 3032629248 90.7% siebel.exp
> 333299214 3659731968 90.8% (totals)

We have imported much larger databases into a linux box in a few hours. What might be limiting? CPU, DB buffer cache, I/O bandwith?

Uwe

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