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November 2013

OSP #1: The Foundation

This is the third of twelve articles in a series called Operationally Scalable Practices. The first article gives an introduction and the second article contains a general overview. In short, this series suggests a comprehensive and cogent blueprint to best position organizations and DBAs for growth.

As a starting point for our discussion of scalable practices, it makes sense to talk about three fundamentals. These will provide a strong foundation for everything else we discuss. First, change history; second, checklists; and third, a few server basics.

Change History

Change History is the single most important concept in Operationally Scalable Practices. Read that sentence again.

The basic idea is simple:

OSP #1: The Foundation

This is the third of twelve articles in a series called Operationally Scalable Practices. The first article gives an introduction and the second article contains a general overview. In short, this series suggests a comprehensive and cogent blueprint to best position organizations and DBAs for growth.

As a starting point for our discussion of scalable practices, it makes sense to talk about three fundamentals. These will provide a strong foundation for everything else we discuss. First, change history; second, checklists; and third, a few server basics.

Change History

Change History is the single most important concept in Operationally Scalable Practices. Read that sentence again.

The basic idea is simple:

OakTable World UK during the UKOUG Tech13 Conference

I am happy to announce that a lot of my OakTable members will do the extra mile by giving extra presentations during the UKOUG Tech13...
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12c In-memory

I wrote a note about the 12c “In-Memory” option some time ago on the OTN Database forum and thought I’d posted a link to it from the blog. If I have I can’t find it now so, to avoid losing it, here’s a copy of the comments I made:

Juan Loaiza’s presentation is probably available on the Oracle site by now, but in outline: the in-memory component duplicates data (specified tables – perhaps with a restriction to a subset of columns) in columnar format in a dedicated area of the SGA. The data is kept up to date in real time, but Oracle doesn’t use undo or redo to maintain this copy of the data because it’s never persisted to disc in this form, it’s recreated in-memory (by a background process) if the instance restarts. The optimizer can then decide whether it would be faster to use a columnar or row-based approach to address a query.

What is Delphix


Who is Delphix?

More and more I’m asked “What is Delphix?”

One reason I’m getting asked is because Delphix is getting more and more exposure. Delphix is used by Fortune #1 Walmart. Delphix is used by social #1 Facebook.  Delphix is used by US Bank #1 Wells Fargo. Delphix is used by networking #1 Cisco. Delphix is used by #1 cable provider Comcast. Delphix is used by #1 auction site Ebay. Delphix is used by #1 insurance New York Life. Delphix is used by #1 chip manufacture Intel.  The list goes on.

Who is this company Delphix and why are they used by the #1 companies in so many domains only 3 years after they started shipping a product?

Delphix

Who is Delphix?

More and more I’m asked “What is Delphix?”

One reason I’m getting asked is because Delphix is getting more and more exposure. Delphix is used by Fortune #1 Walmart. Delphix is used by social #1 Facebook.  Delphix is used by US Bank #1 Wells Fargo. Delphix is use by networking #1 Cisco. Delphix is use by #1 cable provider Comcast. Delphix is used by #1 auction site Ebay. Delphix is used by #1 insurance New York Life. Delphix is used by #1 chip manufacture Intel.  The list goes on.

Who is this company Delphix and why are they used by the #1 companies in so many domains only 3 years after they started shipping a product?

What does Delphix do?

Delphix enables Oracle and SQL Server  customers to clone their databases in minutes for almost no storage.

Excel doesn’t have 3d charts but R does


I wanted to plot a set of data by 3 dimensions.

I wanted to plot I/O read latency by MB/s throughput by number of concurrent readers. Seemed simple. Well it turns out there is no good way to do it in Excel. Sure Excel has 3d charts but, attention, the z axis is treated like rows and not values. For example

Note that the z axis, “users” had 3 values marked  on the axis. Those 3 values are 1,16 and 64. Notice that  16 is as far from 1 as 64 is from 16, ie the distance is not proportional to the value.

There is a free plug-in for Excel called Excel3Dscatterplot, but the data is hard to read, for example

Deadlock

There an interesting example of a deadlock on the OTN database forum:

DEADLOCK DETECTED ( ORA-00060 )
[Transaction Deadlock]

Deadlock graph:
                       ---------Blocker(s)--------  ---------Waiter(s)---------
Resource Name          process session holds waits  process session holds waits
PS-00000001-00000011        92     423     S             33     128     S     X
BF-2ed08c01-00000000        33     128     S             92     423     S     X

One of the responses to the post points out that Oracle error ORA-00060 is an application error and the OP needs to fix his code – and that’s usually a valid comment, especially if the deadlock involves only TX enqueues, TM enquees or a mixture of both; but this deadlock is between a BF and a PS enqueue.

Listener Error from addNode.sh with Second Network

Recently I ran into an problem with 11.2.0.3 RAC. I observed this on a system patched to PSU6 and it looks like a bug to me. But the interesting part isn’t the problem – it’s an impressive and creative workaround that my colleague found over the weekend. I should add that this teammate doesn’t have much background with Oracle RAC though he does have lots of experience with other technologies. His email this weekend surprised me and also gave me a good laugh – hope you find it equally useful and enjoyable!

The problem originated with a requirement I was given when designing this particular cluster system: I was asked to run Data Guard traffic over the backup network instead of the public network. This sounds simple enough if you haven’t worked with RAC. But if you’ve worked with Oracle clusters you realize that nothing is simple anymore. (A big reason I often encourage people to wait on moving to RAC, especially if the main driver is high availability…)

Listener Error from addNode.sh with Second Network

Recently I ran into an problem with 11.2.0.3 RAC. I observed this on a system patched to PSU6 and it looks like a bug to me. But the interesting part isn’t the problem – it’s an impressive and creative workaround that my colleague found over the weekend. I should add that this teammate doesn’t have much background with Oracle RAC though he does have lots of experience with other technologies. His email this weekend surprised me and also gave me a good laugh – hope you find it equally useful and enjoyable!

The problem originated with a requirement I was given when designing this particular cluster system: I was asked to run Data Guard traffic over the backup network instead of the public network. This sounds simple enough if you haven’t worked with RAC. But if you’ve worked with Oracle clusters you realize that nothing is simple anymore. (A big reason I often encourage people to wait on moving to RAC, especially if the main driver is high availability…)