Re: SQL*Loader vs Import performance

In article <k12d6.41493$K8.2044260_at_news1.rdc1.ab.home.com>,   "Petr Schmidt" <petr.schmidt_at_home.com> wrote:
> We are trying to improve performance of DW ETL
> by replacing some import processes by SQL*Loader.
> Interestingly we are finding that direct path SQL*Loader
> takes almost twice as long to run than import. We can
> achieve some scalability by running SQL*Loader in
> parallel, but the whole process still takes more or less
> as long as the import.
>
> Test table load file is about 2.5GB comma delimited,
> approx 6 million records. This is required because the
> table contains mostly VARCHAR columns (131 columns).
> If the table is extracted using fixed size the extract file is
> about 12GB, which presents network transfer problems, etc.
> During the SQL*Loader session the CPU utilization is
> quite high compared to i/o load, which makes me wonder
> how CPU intensive is parsing of each comma delimited
> record.
>
> My past experiences with SQL*Loader have always been
> that it is the fastest method of loading data into an Oracle
> database although I've mostly used fixed size load records.
>
> Any insights into this situation?
> We are running 8.1.6.1 on NT 4.0.
>
> Thanks,
> Petr Schmidt
>
>

Peter,

I've never compared the two, but I was always told that a direct load SQLLDR session would beat an IMPort too. The only thing that comes to mind--and it sounds like you're saavy enough to have checked this--is to drop your indexes before loading the data and then rebuild them afterwards.

Matt.

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http://www.deja.com/ Received on Tue Jan 30 2001 - 10:56:04 CST