Re: Thinking about external tables and performance implications (Linux)

Hi Chris,

I agree. Not a good use case for external tables. I think of external tables as strictly a more convenient drop in replacement for what we used to use SQL*Loader for. Move the data from flat file into DB. That's it. Making external table part of application is a bad idea. Performance and backup and recovery are two reasons that come to mind.

-Mark

On Fri, Sep 30, 2016, 08:08 Chris Taylor <christopherdtaylor1994_at_gmail.com> wrote:

> I'm having a mini-debate (mostly with myself) about when to use Oracle
> external tables and performance implications versus using internal Oracle
> tables.
>
> We get large flat files that we're reading via external table
> definitions. I've noticed some developers writings joins and views against
> the external tables. The flat files beneath the external tables are
> several million rows.
>
> I'm "thinking" this is not really a good use case for external tables as
> Oracle has to access the data through the OS on ext4 filesystem and is
> going to be quite slower than loading that data into an Oracle table with
> appropriate indexes.
>
> I'm wondering if I'm overthinking this or if this is true? (That
> performance will be handicapped when joining to external tables versus the
> same data in an internal table).
>
> Thanks,
> Chris
>
>

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