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January 2017

TCP RMEM Fault in Delphix Target on AWS

So you’ve deployed targets with Delphix on AWS and you receive the following error:

The SQL Loader log file … as data

I had an interesting AskTom question recently where the poster was using SQL Loader to load in tables, but wanted to be able to analyze the resultant log file after execution.  And of course, what better way to analyze..well…anything…than with a database and some SQL.

So we need to be able to access the log file as a table, and an external table is perfect for that, so let’s start there.

Here’s a sample SQL Loader log file (with a little perturbation to preserve anonymity).  It’s quite complex because multiple tables were loaded as part of a single SQL Loader run.

Creating a RAC 12.1 Data Guard Physical Standby environment (3)

In the previous two parts of this series you read about my lab environment and the preparations on the network side as well as the database. In this part I’ll cover the database duplication. Again, this won’t be a short post …

NOTE: As always, this is just a demonstration using VMs in my lab, based on my notes. Your system is most likely different, so in real-life you might take a different approach. The techniques I am using here were suitable for me, and my own small scale testing. I tried to make sure they are valid, but you may want to allocate more resources in your environment. Test, test, test on your own environment on test kit first!

Step 1: Create an initialisation file

The next step is the preparation of an initialisation file. I am taking NCDBA as the sample and transfer it over to rac12sec1:

How do I get my trace files on a db-as-a-service

Yeah, sure it would be cool to crank up some big time powered VM’s in the cloud and let rip, but the reality is – if you’re starting out on a cloud exploration, you probably want to (initially at least) just dip your toes in the water and start with something small.  For example, if I wanted to play with 12c Release 2, I can just sign up for an Exadata Express service so I can explore the new features without breaking the bank.

But whatever the need, accessing a database as a service as opposed to a server, there’s often that fear of “handing over the reins”, that is, that I’ll not be able to do the things I want to do, especially when it comes to OS level access.  And for a developer or DBA, perhaps a thing that might raise alarm bells is: “How will I access my trace files ?”

Oracle Database Cloud (DBaaS) Performance - Part 2 - Storage

In this second part of this installment I'll focus on the performance figures related to I/O encountered when the corresponding tests were performed on the platform.


When running with minimum sized buffer cache, direct and asynchronous I/O enabled, the following average read-only IOPS figures were measured over a period of several days (this is the test described in part three of the "performance consistency" series) .

First, running on a 4 OCPU single instance configuration (8 CPUs / 8 cores as outlined in the previous part) with either four or eight sessions:

Funny "ORA-01017: invalid username/password; logon denied" during DataGuard switchover operation from DG broker

Recently one of my customers encountered a problem when they tried to perform a switchover from DataGuard broker command line interface.

$ dgmgrl /
DGMGRL for Linux: Version - 64bit Production

Copyright (c) 2000, 2013, Oracle. All rights reserved.

Welcome to DGMGRL, type "help" for information.
Connected as SYSDG.
DGMGRL> show configuration;

Configuration - db12c

  Protection Mode: MaxPerformance
  db12c  - Primary database
    sdb12c - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS   (status updated 26 seconds ago)

DGMGRL> validate database sdb12c;

  Database Role:     Physical standby database
  Primary Database:  db12c

  Ready for Switchover:  Yes

Auditing Oracle database stopping and starting using the ELK stack

This blog post is about two things: one how you can monitor who is bringing you database up and down (there is a twist at the end!) and two how you can very conveniently do that with aggregated logs in a browser with a tool called ‘Kibana’, which is the K in ELK.

plsql promises - chaining and thenables

So last blog entry Do or do not. on the promises library, covered the basics of what promises can give us.

This entry will cover more around chaining of promises and how you can easily run your code in parallel
and still make sure they run in the right order, when needed.

I’m speaking at Advanced Spark Meetup & attending Deep Learning Workshop in San Francisco

In case you are interested in the “New World” and happen to be in Bay Area this week (19 & 21 Jan 2017), there are two interesting events that you might want to attend (I’ll speak at one and attend the other):

Advanced Spark and TensorFlow Meetup

I’m speaking at the advanced Apache Spark meetup and showing different ways for profiling applications with the main focus on CPU efficiency. This is a free Meetup in San Francisco hosted at AdRoll.

Ozar Professional Salary Data- Post 1

So Brent Ozar’s group of geeks did something that I highly support-  a survey of data professional’s salaries.  Anyone who knows me, knows I live by data and I’m all about transparency.