Hi All,
I was wondering if someone could maybe help me out with an unusual observation
I have on a couple of test systems.
I have a user reporting that they are seeing differences in performance between
the database on a VM (which is running 'fast') and a database on a physical
(which is running slow)
They are performing a load from MongoDB via a PHP app into the oracle database.
In both tests the same source database is being used.
I've done a quick overview on each of the systems and the only thing that is
jumping out at me is that on the faster DB the log file sync time is much lower
on the faster one. (the output was gather using oratop) Both DB's are 12.1.0.2.
The faster one is on CentOS 6.6 and the Slower one on Redhat 5.11.
Slow DB
EVENT (Real-Time) AVG: TOT WAITS TIME(s) AVG_MS PCT WAIT_CLASS
log file parallel write 20008284 23783 1.2 100 System I/O
log file sync 1730 9 5.2 0 Commit
DB CPU 0 0
Fast DB
EVENT (Real-Time) AVG: TOT WAITS TIME(s) AVG_MS PCT WAIT_CLASS
log file parallel write 20389439 28216 1.4 100 System I/O
log file sync 179674 74 0.4 0 Commit
SQL*Net message to client 7 0 0.0 0 Network
DB CPU 0 0
I'm also a bit confused as to how the log file sync time can be shorter than
the log file write time.
Any assistance or advice would be appreciated.
Regards,
Christopher Osborne
Information in this email including any attachments may be privileged,
confidential and is intended exclusively for the addressee. The views expressed
may not be official policy, but the personal views of the originator. If you
have received it in error, please notify the sender by return e-mail and delete
it from your system. You should not reproduce, distribute, store, retransmit,
use or disclose its contents to anyone. Please note we reserve the right to
monitor all e-mail communication through our internal and external networks.
SKY and the SKY marks are trademarks of Sky plc and Sky International AG and
are used under licence. Sky UK Limited (Registration No. 2906991), Sky-In-Home
Service Limited (Registration No. 2067075) and Sky Subscribers Services Limited
(Registration No. 2340150) are direct or indirect subsidiaries of Sky plc
(Registration No. 2247735). All of the companies mentioned in this paragraph
are incorporated in England and Wales and share the same registered office at
Grant Way, Isleworth, Middlesex TW7 5QD.