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Deception

One of the difficulties with trouble-shooting is that’s it very easy to overlook, or forget to go hunting for, the little details that turn a puzzle into a simple problem. Here’s an example showing how you can read a bit of an AWR report and think you’ve found an unpleasant anomaly. I’ve created a little model and taken a couple of AWR snapshots a few seconds apart so the numbers involved are going to be very small, but all I’m trying to demonstrate is a principle. So here’s a few lines of one of the more popular sections of an AWR report:

Refreshing VDB With Sales History Data

Now that I’ve loaded a ton of transactions and did a bunch of work load on my source database with the SH sample schema and Swingbench, I’ve noted how little impact to the databases using different cloud tools, (which will come in a few later posts) now I’m going to show you how easy it is to create a new VDB from all of th

How many members for standby redo logs?

I see lot of databases with two members for redo logs and also two members for standby redo logs. Why not, but when asking I realized that there are some mis-comprehension about it. And what was recommended 10 years ago may be different today.

Starting an instance with sqlplus and running into ORA-27302: failure occurred at: skgpwinit6

Recently I was applying the data dictionary part from an (exadata bundle) patch and ran into the following errors:

Swingbench with the AWS Trial

Swingbench is a one of the best choices for easy loads on a database.

Google Cloud Platform instances and Oracle Database

When it comes to choose a cloud instance to run Oracle Database, you want to be able to run your workload on the minimum CPU cores. This is why in a previous post I measured how many logical reads per seconds can be achieved with a SLOB workload, on AWS which is often the first considered, and will probably do it on Azure in the future. I did the same on the Oracle Cloud which is the only one where Oracle make it easy to run an license the Oracle Database.

Manually Adding Sales History, (SH) Schema to 11.2.0.4

Most people know I like to do things the hard way… </p />
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Quiz Night

The following is a straight, continuous, untouched, cut-n-paste from an SQL*Plus session on 12.1.0.2. How come the update doesn’t execute in parallel – noting that parallel DML has been enabled and the tablescan to identify rows to be updated does execute in parallel ?

Join Elimination

A question has just appeared on OTN describing a problem where code that works in 11g doesn’t work in 12c (exact versions not specified). The code in question is a C-based wrapper for some SQL, and the problem is a buffer overflow problem. The query supplied is as follows:


select T1.C1 from T1, T2 where T1.C1 = T2.D1;

The problem is that this works in 11g where the receiving (C) variable is declared as

char myBuffer [31];

but it doesn’t work in 12c unless the receiving variable is declared as:

Oracle database 12.1.0.2.170117 (januari 2017 PSU) and TDE wallets

Recently, I was trying to setup TDE. Doing that I found out the Oracle provided documentation isn’t overly clear, and there is a way to do it in pre-Oracle 12, which is done using ‘alter system’ commands, and a new-ish way to do it in Oracle 12, using ‘administer key management’ commands. I am using version 12.1.0.2.170117, so decided to use the ‘administer key management’ commands. This blogpost is about an exception which I see is encountered in the Januari 2017 (170117) PSU of the Oracle database, which is NOT happening in Oracle 12.2 (no PSU’s for Oracle 12.2 at the time of writing) and Oracle 12.1.0.2 April 2016 and October 2016 PSU’s.

In order to test the wallet functionality for TDE, I used the following commands: