Category Archives: Monitoring

Oracle OpenWorld 2015

Submitted my Oracle OpenWorld 2015 presentation earlier.  Today is the last day to submit proposals for presentations or tutorials.

Oracle have extended their deadline for proposals until May 6th!



Tagged , , , , ,

DBA 3.0 – How to Become a Real-World Exadata DBA – IOUG Collaborate 2015

According to a Book of Lists survey, 41% of people’s biggest fear is “public speaking”.  To put that into perspective, “death” is the biggest fear for 19%, “flying” for 18% and “clowns” don’t even register (which does make me seriously doubt the survey’s credibility).

I gave my first public presentation at IOUG Collaborate 2015 last week in Las Vegas and I didn’t die.

Why did do make your presentation debut at the second largest Oracle event on the calendar?  Excellent question.

Continue reading

Tagged , , , ,

How Do *YOU* Measure SmartScans?

With SmartScans being the most important (and most unique) performance feature for Exadata, it’s incredibly useful to measure how well you’re making use of it.

But how?

There are a number of ways you can measure this, but none of these seem to be the DEFINITIVE method to do so.  Instead, it’s probably a good idea to more than one formula, if not all, to get a good idea of our SmartScan usage.

Why are there multiple formulas?  Because the existing database metrics don’t quite capture what we’re looking to measure.  For instance:

  • physical read total bytes‘ –  is all the data including compressed data AND SmartScan-ineligible data.
  • cell physical IO interconnect bytes‘  –  includes the writes (multiplied due to ASM mirroring) AND the reads.
  • cell IO uncompressed bytes‘  –  is the data volume for predicate offloading AFTER the Storage Index filtering and any decompression
  • cell physical IO interconnect bytes returned by smart scan‘  –  includes uncompressed data.

Continue reading

Tagged , , ,

My Collaborate IOUG 2015 Abstract

I will be presenting DBA 3.0 or “How to Become a Real-World Exadata DBA” at Collaborate 2015 – IOUG’s annual user conference – from April 12th to 16th at the Mandalay Bay Resort and Casino in Las Vegas. I submitted this as my abstract:

“DBA resources are more scarce than ever before and it can be very difficult to allocate time on anything but keeping the lights on – even when an organization has made a (substantial) hardware investment in Exadata.

However, if Exadata is treated like any other Oracle database, the promised “extreme performance” will likely be very underwhelming to developers, users and managers and can become unwieldy for DBAs to support.

On the other hand, when an organization configures and supports Exadata properly, they can realize exponential performance improvements in key IT infrastructure, can facilitate better business decisions and may actually reduce infrastructure costs.

The customer has bought a sports car – but might not realize that they haven’t taken it out of second gear (yet).

I will talk about the evolution of Exadata and then get into the “nuts and bolts” of how to support a high-performance Exadata environment as a Production DBA.

I will discuss how to get performance improvements of up to 20x, what NOT to do as an Exadata DBA and how Exadata can become the foundation of your organization’s high-performance enterprise infrastructure.”

I hope to see you in Las Vegas!

Tagged , , ,

UKOUG 2014 – Dan Norris – Exadata Security Best Practices

Dan Norris of the Maximum Availability Architecture team gave what sounded like a very interesting presentation at UKOUG 2014. There seemed to be a lot of really cool stuff at this year’s event, which is to be expected as I no longer reside in the UK!

I encourage you to take a look at the slides, but also at the interesting links he provided:

Naturally, he also quoted a plethora of My Oracle Support notes – some of the greatest hits and some which you might not have seen before:

  • Responses to common Exadata security scan findings (Doc ID 1405320.1)
  • Oracle Sun Database Machine X2-2/X2-8, X3-2/X3-8 and X4-2 Security Best Practices (Doc ID 1071314.1)
  • How to change OS user password for Cell Node, Database Node , ILOM, KVM , Infiniband Switch , GigaBit Ethernet Switch and PDU on Exadata Database Machine (Doc ID 1291766.1)
  • Exadata Database Machine and Exadata Storage Server Supported Versions (Doc ID 888828.1)
  • Information Center: Oracle Exadata Database Machine (Doc ID 1306791.2)

Happy reading!

Tagged , , , , ,

ORAchk and Collection Manager

Quite by chance, I noticed today that Oracle are now offering an exachk-like health check for non-Exadata systems: ORAchk.

This includes some of the exachk functionality and replaces the RACcheck tool for Oracle databases (both clustered and single-instance).

One of the components of ORAchk is the Collection Manager, a ApEx web app, which provides a unified dashboard view of collections (ORAchk, RACcheck and exachk) across your environment.

The Collection Manager uses ApEx 4.2 and can be run against all editions of the database (XE, SE1, SE, EE) or higher. It is supported as part of your support contract, with the exception of the XE edition – you’ll have to visit the OTN forums for help with that.

There are two features in particular which interest me: the ability to compare different health check runs and the creation of incidents for tracking of issues.

Oddly enough, I had just started to create my own system to do just this today – which would have only provided a fraction of what this does, of course. I just need to find somewhere to run ApEx, a spare database and to brush up on my ApEx knowledge.

As a slight tangent, I think it’s a little strange that Oracle are running this on ApEx. I presume this is because it’s an early version and I would imagine that this – along with the OCM/ASR functionality – might end up making its way into a future release of OEM pretty soon as Oracle continue to mature the management of Exadata and its cohorts.

Useful links:


Tagged , , , ,

Exadata-Specific Metrics in AWR

After our ExCite review earlier in the year, I managed to borrow/steal the following metrics to determine IOPS, HCC efficiency and SmartScan efficiency.

I’m a bit wobbly on the SmartScan formula, so if anyone has any corrections, please feel free to offer them 🙂


% of all physical reads served by the FlashCache
— physical read total IO requests / cell flash cache read hits

adjusted total read requests
– we had to double this because WE are using 16k blocks and IOPS is based on 8k blocks
— (physical read total IO requests – cell flash cache read hits) * 2

adjusted total write requests
– we had to double this because WE are using NORMAL redundancy on the ASM diskgroup
— physical write total IO requests * 2

I/O operations
– per second if we take the “Per Second” metric in AWR
— “adjusted total read requests” + “adjusted write read requests”

N.B. an X3-2 quarter-rack has an IOPS rating of 6,000 – I discovered this when the ExCite experts pointed it out (and we had exceeded it).


average number of rows that each compression unit contains – effectiveness of what the data we do compress with EHCC
— EHCC total rows for decompression / EHCC CUs decompressed


total physical IO bytes saved by SmartScan
— cell physical IO bytes eligible for predicate offload – cell physical IO interconnect bytes returned by smart scan

ratio of SmartScan efficiency
— cell physical IO interconnect bytes returned by smart scan / (cell IO uncompressed bytes + cell physical IO bytes saved by storage indexes)

Tagged , , , , , , ,
%d bloggers like this: