Who's online

There are currently 0 users and 36 guests online.

Recent comments


Scripts to Download Oracle Database 12c Release 2 Documentation

In the past (here, here and here) I already shared with you the scripts I use to download the Oracle Database documentation. The aim of this short post is to reference the scripts I just wrote for the latest version: 12c Release 2.

Happy downloading as well as happy reading!

Adaptive Query Optimization: Backport of 12.2 Configuration in

I finally managed to install and test patch 22652097 (PROVIDE SEPARATE CONTROLS FOR ADAPTIVE PLANS AND ADAPTIVE STATISTICS FEATURES). Actually, I installed and tested two patches. The first was installed on top of “Oracle Database Patch 23054246 – Database Patch Set Update” (from now on, PSU). The second was installed on top of “Patch 24448103 – Database Proactive Patch” ( PBP).

From a functional point of view, both patches provides the 12.2 configuration in 12.1 as I describe it in this post. In fact, the behavior of setting the (un)documented initialization parameters as well as all the default values are the same. I was able to find only two differences between 12.2 and a patched 12.1.

Ad – Oracle Database 12c Release 1 and 2: New Performance Features

In the past I gave a number of 1-day seminars about the new performance features available in Oracle Database 12c Release 1. On the 22nd of February, for the first time, I’ll give an updated version of that seminar with content about both Release 1 and Release 2. Note that because there is more content, I extended it from one day to two days.

Initialization Parameters Set at the PDB Level Are Not Always Honored

Before describing the issue that lead to this post, let’s shortly review how the handling of initialization parameters works in a multitenant environment.

Oracle 12cR2: Database parameters

For those in a desperate need to learn all 4841 database parameter variations of the…

Approximate Aggregate Transformation (AAT)

There are situations where approximate results are superior than exact results. Typically, this is the case when two conditions are met. First, when the time and/or resources needed to produce exact results are much higher than for approximate results. Second, when approximate results are good enough. Approximate results are for example superior in case of exploratory queries or when results are displayed in a visual manner that doesn’t convey small differences.

Trace Files Split in Multiple Parts

Last January, in the following tweet, I pointed out that the documentation vaguely mentions that a trace file may be split into several files.

Adaptive Query Optimization Configuration: Parameters, Preferences and Fix Controls

The aim of this post is to summarize the knowledge about the 12.1 and 12.2 adaptive query optimizer configuration that, as far as I know, is spread over a number of (too many) different sources.

First of all, let’s shortly review which adaptive query optimization features exist:

SQL Trace in Oracle Database Exadata Express Cloud Service

Today I started having a look to the Oracle Database Exadata Express Cloud Service announced last week at Oracle OpenWorld. Note that since the amount of resources provided (in summary, 1 OCPU, 20 or 50 GB of database storage) is very limited, in general, in my opinion that service will only be useful for functional tests. In fact, if it wasn’t because that is the very first 12.2 release ( according to V$VERSION) available, I doubt I would care about it…

A first important thing to know is that the service gives access to a PDB via SQL*Net only (in addition to the web-based interfaces like APEX). In other words, the OS access is precluded.

Oracle WebLogic 12cR2 and ADF Runtime Installations…

The new versions of the WebLogic 12cR2 and ADF could not have come at a worse time for me. My top priority is learning about the 12cR1 version of the database. Second, is getting to grips with Cloud Control 12cR3. Third on the list is getting up to speed with the changes in WebLogic 12cR2 and ADF. Unfortunately, my personal priorities don’t quite match my work priorities, so WebLogic 12cR2 has moved up the list for a while. As a result, I did some installations last night.