SLOB 2.2 Not Generating AWR reports? Testing Large User Counts With Think Time? Think Processes and SLOB_DEBUG.

I’ve gotten a lot of reports of folks branching out into SLOB 2.2 large user count testing with the SLOB 2.2 Think Time feature. I’m also getting reports that some of the same folks are not getting the resultant AWR reports one expects from a SLOB test.

If you are not getting your AWR reports there is the old issue I blogged about here (click here). That old issue was related to a (more...)

RMOUG Training Days 2015!

OK, Oracle EM hat off, RMOUG Training Days hat on! :)

So as many of you know, RMOUG Board of Directors made the smart move after I joined Oracle, instead of losing a valuable member of the board, they moved me to being a non-voting board member emeritus and realized that I could still serve as the Training Days Conference Director.  The conference is by far, the most demanding position on the board and its (more...)

Oracle database operating system memory allocation management for PGA – part 2: Oracle 11.2

This is the second part of a series of blogpost on Oracle database PGA usage. See the first part here. The first part described SGA and PGA usage, their distinction (SGA being static, PGA being variable), the problem (no limitation for PGA allocations outside of sort, hash and bitmap memory), a resolution for Oracle 12 (PGA_AGGREGATE_LIMIT), and some specifics about that (it doesn’t look like a very hard limit).

But this leaves out Oracle version (more...)

Create Histograms On Columns That Already Have One

RSS content

The default value of METHOD_OPT from  10g onwards is ‘FOR ALL COLUMNS SIZE AUTO’.

The definition of AUTO as per Oracle documentation is  :
AUTO: Oracle determines the columns to collect histograms based on data distribution and the workload of the columns.

This basically implies that Oracle will automatically  create histograms on those  columns which have skewed data distribution and there are  SQL statements  referencing those columns.

However, this gives rise to (more...)

Adventures in RAC: gc buffer busy acquire and release

It seems that I’m getting more and more drawn into the world of performance analysis, and since I sometimes tend to forget things I need to write them down. I almost enjoy the “getting there” more than ultimately solving the problem. You pick up quite a few things on the way.

This environment is Exadata 12.1.1.1.1/Oracle 12.1.0.2 but as with so many things the fact that the database (more...)

TROUG Day Ankara 2014

poster_ankara14As Turkish Oracle User Group (TROUG), we will organize our second meeting in Ankara on December 23rd. The event will be held at the Chamber of Electrical Engineers (EMO). The main theme of the meeting is Oracle 12c. There will be 4 sessions about new features of Oracle 12c (Database In-Memory, Active Data Guard, RAC and Flex ASM and Multitenancy). I usually do presentations about Enterprise Manager but this time, I have picked a more (more...)

Managing Oracle Database 12c with Enterprise Manager – Part III


We are discussing the management of Oracle Database 12c in Oracle Enterprise Manager 12c. In our previous blog posts on this topic, we came to the Provision Pluggable Databases page as seen below. This is accessible via the Container Database Home Page in Enterprise Manager 12c, from the Oracle Database menu.
When it comes to licensing for this page, it needs to be clearly understood. The licensing requirements for the Enterprise Manager Database Lifecycle Management (more...)

Managing Oracle Database 12c with Enterprise Manager – Part II


Friends,
In the last post, we saw what the discovery of an Oracle 12.1 Container Database (CDB) would look like in Oracle Enterprise Manager 12c, with the CDB and component PDBs all being discovered by the EM Agent that has been installed on the target database server.
Drilling down to a CDB, the following screenshot illustrates how the CDB Home page would appear. The Home Page shows the list of Pluggable Databases in (more...)

Managing Oracle Database 12c with Enterprise Manager – Part I


A friend from a lovely country in South America wrote to me :
“Hi My Friend!! My colleague has installed an Oracle Database 12c Container database (CDB) and he has created 2 Pluggable databases (PDBs) on it. He is keen to manage the CDB and PDBs in Enterprise Manager.
“But, when he adds the database to Enterprise Manager 12c, he sees it like a non-CDB and there is no way to work with PDB’s (in (more...)

NWOUG Women in Technology Scholarship

This year the Northwest Oracle User Group created a scholarship for an outstanding female student in the Portland State University Computer Engineering  Department.  The criteria was straight-forward.  In addition to being an outstanding student we asked all the applicants to answer this question:

“How does employee participation in professional communities add value for their employers?”

The arguments for promoting WIT are well-documented elsewhere, and it had a bearing on our decision.   But we also (more...)

Oracle database operating system memory allocation management for PGA

This post is about memory management on the operating system level of an Oracle database. The first question that might pop in your head is: isn’t this a solved problem? The answer is: yes, if you use Oracle’s AMM (Automatic Memory Management) feature, which let’s you set a limit for the Oracle datababase’s two main memory area’s: SGA and PGA. But in my opinion any serious, real life, usage of an Oracle database on Linux (more...)

“4k bug” is not a bug

A couple of weeks back I received an update on my “4k bug” SR (slow multirow DML performance for small block sizes). As it turns out, the observed behavior is not a bug. It’s actually more interesting than that. It is an undocumented feature that controls the insert mode depending on the estimated row size (the sum of all column sizes). If the estimated column size exceeds the size of the block, then Oracle switches (more...)

Develop against the versions in the Yum repositories!

I saw a tweet by Simon Haslam at the weekend that read,

“I’m v surprised to read that @Atlassian Stash needs newer git than in the latest RHEL/OL6 repos!”

I had a similar experience at the weekend too, but this time with Oracle REST Data Services (ORDS) 3.0 EA. According to the documentation, it requires the following version of Tomcat.

“Apache Tomcat Release 7.0.56 or later”

So let’s have a look (more...)

GOLDENDATE HA MAA RAC ACFS XAG

Purpose is to demonstrate how to create HA for Bi-Directional Replication Goldengate installed on ACFS with RAC cluster using XAG.

XAG simplifies the process since there are no requirements to create action scripts.

Please review REFERENCE section for versions used in test case and versions requirements.

Goldengate is installed on ACFS for simplicity; otherwise, at a minimum the following directories br, dirchk, dirdat, dirtmp will need to be on shared storage with symbolic links if (more...)

Day 3+ of UKOUG Tech 14

Sorry it’s taken a couple of days to finish off this series of blog posts on UKOUG Tech 14. I had expected to get some time on the trip back to write this, but as you’ll see if you keep reading, that really didn’t happen. So let’s go back to Day 3 of the conference.

I started the day by attending Patrick Hurley’s “Adventures in Database Administration” session. This was quite different to the normal (more...)

ORA-4068 and CONSTANT keyword…good and bad

Anyone that has ever coded PLSQL will be familiar with the error ORA-4068, where you had some state persisted in a session due to a package variable, and then when you change the package, the state is cleared along with an ORA-4068.  Here’s a quick example:

 

Session 1 

SQL> create or replace
  2  package PKG is
  3    procedure P;
  4  end;
  5  /

Package created.

SQL> create or replace
  2  package body  (more...)

AZORA – Arizona Oracle User Group meeting January 20th

AZORA is planning a meeting January 20th.  Here is the link to RSVP: url

Hope to see you there. :)

– Bobby

EM12c Management Agent, OutOfMemoryError and Ulimits

While enjoying the lovely Liverpool, UK weather at Tech14 with UKOUG, (just kidding about that weather part and apologies to the poor guy who asked me the origin of “Kevlar” which in my pained, sleep-deprived state I answered with a strange, long-winded response…. :)) a customer contacted me in regards to a challenge he was experiencing starting an agent on a host that was home to 100’s of targets.

        oracle_database.DB301.com - LOAD_TARGET_DYNAMIC  (more...)

UKOUG post conference geek update part 1 – ACFS for Oracle databases

One of the many interesting things I heard at the conference this time around was that Oracle’s future direction includes the use of database files on ACFS. When ACFS came out this was strictly ruled out, but has been possible for a little while now, I believe with 12.1.0.1.0. With the Oracle Database Appliance (ODA) using this deployment option and hearing about it at the conference, a little further investigation was (more...)

push_pred – evolution

Here’s a query (with a few hints to control how I want Oracle to run it) that demonstrates the difficulty of trying to solve problems by hinting (and the need to make sure you know where all your hinted code is):


select
	/*+
		qb_name(main)
		leading (@main t1@main v1@main t4@main)
		push_pred(v1@main)
	*/
	t1.*,v1.*,t4.*
from
	t1,
	(
	select	/*+ qb_name(inline) no_merge */
		t2.n1, t3.n2, count(*)
	from	t2, t3
	where exists (
		select	/*+ qb_name(subq) no_unnest push_subq */
			 (more...)