I’d only just heard of it recently, but the DBA experiencing it said it was
any pull from external table to do bulk loads. There’s a number of bugs in
Oracle support for the search criteria: “12.1 external table read”
*Bug 21553593 20+ million directory objects causing slow reads from
external tables*
*Bug 19597583 "external table reads" during local PDB *
On Fri, Jan 12, 2018 at 4:58 PM Sanjay Mishra <smishra_97@xxxxxxxxx> wrote:
Kellyn--
thanks for the information. Do you have more details about the bug ?
Sanjay
On Friday, January 12, 2018, 4:22:39 PM EST, Kellyn Pot'Vin-Gorman <
dbakevlar@xxxxxxxxx> wrote:
Be aware, there is also a known bug in 12.1 with external tables causing
performance issues.
Length
On Fri, Jan 12, 2018 at 2:31 PM Sanjay Mishra <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
Mark
Oracle 12.1.2 and it is Single Node RAC instance and is Enterprise
Edition. The issue with Select is where Clause for 2-3 column where Index
can definitely be helpful but External table dont allow index. Select was
Tried with Parallel but no difference in terms of performance. One option
trying is MV and as data is not much but table is extensively used for
various purpose.
Sanjay
On Friday, January 12, 2018, 2:29:48 PM EST, Powell, Mark <
mark.powell2@xxxxxxx> wrote:
Sanjay, you did not identify your Oracle version and edition nor post the
actual code you have an issue with but consider the following.
I do not have access to a server where I can test right now but I believe
that you can select from an external table using parallel query if you are
on EE.
Mark Powell
Database Administration
(313) 592-5148
------------------------------
*From:* oracle-l-bounce@xxxxxxxxxxxxx <oracle-l-bounce@xxxxxxxxxxxxx> on
behalf of Sanjay Mishra <dmarc-noreply@xxxxxxxxxxxxx>
*Sent:* Friday, January 12, 2018 2:23:40 PM
*To:* Oracle-L Freelists
*Subject:* External table performance
Can someone share the Tuning activites that can be done for Selecting data
from External table in 12c (12.1)? I am working on project that is getting
every 6hourly data as flat file from external source and then has to be
selected from ORacle table for some processing. Data is only 50K records
but Select is taking time. It is Local Storage where File is located. I
don;t think we can have indexes yet and so checking experience from the
experts.
Tx
Sanjay
--
[image: Kellyn Pot'Vin on about.me]
Kellyn Pot'Vin-Gorman
about.me/dbakevlar
<http://about.me/dbakevlar>
