Thinking about external tables and performance implications (Linux)
From: Chris Taylor <christopherdtaylor1994_at_gmail.com>
Date: Fri, 30 Sep 2016 07:07:28 -0500
Message-ID: <CAP79kiTsocQ5MYRBdGGqVu3oY7W4jriiD9MvozXsvt0Gu3+Hag_at_mail.gmail.com>
I'm having a mini-debate (mostly with myself) about when to use Oracle external tables and performance implications versus using internal Oracle tables.
Date: Fri, 30 Sep 2016 07:07:28 -0500
Message-ID: <CAP79kiTsocQ5MYRBdGGqVu3oY7W4jriiD9MvozXsvt0Gu3+Hag_at_mail.gmail.com>
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
-- http://www.freelists.org/webpage/oracle-lReceived on Fri Sep 30 2016 - 14:07:28 CEST