Epicaricacy

Wednesday’s word is Epicaricacy, meaning to take joy in the misfortune of others. Yes, this is the (admittedly rare) English word that doesn’t exist, causing an outbreak of German in otherwise sane sentence.

It’s interesting that taking pleasure from others misfortune as a single ‘concept'; Schadenfreude, skadeglädje, leedvermaak, skadefryd, skadeglädje and vahingonilo, are all Northern European words (being German, Swedish, Dutch, Danish, Norwegian and Finnish respectively). Us North Europeans seem to like little more that a good (more...)

Updated (XML) Content Section

“Once per year I try to update the “XML Content” page that, in principle, should…

CERN talks at UKOUG TECH 2014

This is a short blog post with a list of the talks by CERN people at the UKOUG TECH 2014 conference in Liverpool. We hope to see many of you there!

 

STATISTICS COLLECTOR Row Source Operation and LOBs

The aim of the STATISTICS COLLECTOR row source operation, which is used in adaptive plans, is to buffer all data produced by its child operation until it is known whether the inflection point is crossed. It goes without saying that buffering requires memory and, therefore, Oracle Database has to limit the amount of memory that can be allocated for that purpose. As a result, in some situations no adaptive plans can be used because according (more...)

ORA 700’s make me grumpy ( well or at least confused )

Geez Louise I guess I coulda/shoulda known about this before now.

At some point the oracle software ( 11.2 ish ? 11.1 ish ? ) now starts getting worried and kind of grumpy.

You apparently can get ORA 700's under certain circumstances.  It's not a huge problem apparently ( yet ) when the software decides to let you know ... ( but it might become one later maybe ? ).

I saw this one on a new (more...)

VirtualBox and Windows driver verifier

I was troubleshooting some Windows hangs on my Desktop system running Windows 8 and enabled driver verifier. Today when I tried to start VirtualBox it failed with this error message.

Failed to load VMMR0.r0 (VERR_LDR_MISMATCH_NATIVE)

Most of the online forums were asking to reinstall VirtualBox to fix the issue. But one of the thread mentioned that it was being caused by Windows Driver Verifier. I disabled it, restarted Windows and VirtualBox worked like a (more...)

Controlling RMAN channels on RAC

This was sent to me for posting  by my friend and ex-colleague Vitaly Kaminsky ….

I have recently worked with the customer where standard RMAN backups of production 2-node cluster (11.2.0.3) were getting too big and taking longer than 24 hours to run.

The problem with this particular cluster was the fact that ALLOCATION of RMAN connections to the instances of the cluster was controlled by SCAN and driven by the load-balancing (more...)

Upgrades

I have a simple script that creates two identical tables , collects stats (with no histograms) on the pair of them, then executes a join. Here’s the SQL to create the first table:


create table t1
nologging
as
with generator as (
	select	--+ materialize
		rownum id
	from dual
	connect by
		level <= 1e4
)
select
	trunc(dbms_random.value(0,1000))	n_1000,
	trunc(dbms_random.value(0,750))		n_750,
	trunc(dbms_random.value(0,600))		n_600,
	trunc(dbms_random.value(0,400))		n_400,
	trunc(dbms_random.value(0,90))		n_90,
	trunc(dbms_random.value(0,72))		n_72,
	trunc(dbms_random. (more...)

Oracle AWR Reports: When Averages Lie

truth-sign

I was recently contacted by a customer who runs a busy ERP system on their Oracle database. Their users have been screaming for some time about unpredictable performance, where application screens which would usually open in under a second suddenly take an age. ERP systems are legendary for this, of course, because as each screen loads the application tends to fire off a glut of queries to populate all the various fields, graphs and so (more...)

How do you Explain Oracle in 50 Minutes?

I’ve done a very “brave”* thing. I’ve put forward a talk to this year’s UKOUG Tech14 conference titled “How Oracle Works – in under 50 minutes”. Yes, I really was suggesting I could explain to people how the core of Oracle functions in that time. Not only that, but the talk is aimed at those new to Oracle technology. And it got accepted, so I have to present it. I can’t complain about that (more...)

Little things worth knowing: creating the Swingbench order entry schema “lights out”

This is a little note, primarily to myself I guess, about the creation of the order entry schema (part of Swingbench, written by Dominic Giles) when no VNC sessions are available (although you can almost always use port-forwarding :). Instead, you can create the schema on the command line. I always execute commands on remote systems in screen for increased peace of mind. Should the network drop, the order entry generation will continue as if (more...)

The Perfect Gift For The Oracle DBA: Top 5 DBA T-Shirts

The Perfect Gift For The Oracle DBA: Top 5 DBA T-Shirts


It's that time of year again and I can already hear it, "Dad, what do you want for Christmas?" This year I'm taking action. Like forecasting Oracle performance, I'm taking proactive action.

Like most of you reading this, you have a, let's say, unique sense of humor. I stumbled across the ultimate geek website that has an astonishing variety of t-shirts aimed at (more...)

Life of an Oracle I/O: tracing logical and physical I/O with systemtap

Topic: This post is about tracing logical and physical reads in Oracle using systemtap. You will find a few examples illustrating the main mechanisms used by Oracle to do physical and logical I/O and you will learn how to build systemtap scripts to further explore and troubleshoot Oracle I/O.

How to Backup and Restore PostgreSQL 9.3 Databases

In my previous blog post, I explained how to install PostgreSQL 9.3 on Oracle Linux. As a DBA, one of the first things we want to learn is how we can recover the database in case of a failure. So in this blog post, I’ll show how to backup and restore PostgreSQL databases in a server. We’ll backup PGDATA directory, so it’ll contain all databases in the instance (remember that PostgreSQL is a (more...)

Adding a DEFAULT column in 12C

I was at a talk recently, and there was an update by Jason Arneil about adding columns to tables with DEFAULT values in Oracle 12C. The NOT NULL restriction has been lifted and now Oracle cleverly intercepts the null value and replaces it with the DEFAULT meta-data without storing it in the table. To repeat the 11G experiment I ran recently:

 

SQL> alter table ncha.tab1 add (filler_default char(1000) default 'EXPAND' not  (more...)

Using runInstaller to check Prereqs with responseFile

The SILENT method

[grid@rac01:/media/sf_Linux/11.2.0.4/grid]
$ ./runInstaller -silent -executePrereqs -showProgress -waitforcompletion -force -responseFile /media/sf_Linux/11.2.0.4/grid/grid_crs_config.rsp
Starting Oracle Universal Installer...

Checking Temp space: must be greater than 120 MB.   Actual 48807 MB    Passed
Checking swap space: must be greater than 150 MB.   Actual 8191 MB    Passed
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2014-11-30_06-40-05PM. Please wait ...[grid@rac01:/media/sf_Linux/11.2.0.4/grid]
$ cd /u01/app/oraInventory/logs/
[grid@rac01:/u01/app/oraInventory/logs]
$ ls -lrt
total 84
-rw-r--r--. 1  (more...)

Avoid false errors with runcluvfy.sh for VirtualBox

My typical VirtualBox network configuration is: eth0 (NAT), eth1 (Host Only), eth2(Internal)

runcluvfy.sh stage -pre crsinst -n rac01,rac02 -r 11gR2 -fixup -fixupdir /tmp – FAILED

Node connectivity passed for subnet "10.0.2.0" with node(s) rac02,rac01

ERROR:
PRVF-7617 : Node connectivity between "rac01 : 10.0.2.15" and "rac02 : 10.0.2.15" failed
TCP connectivity check failed for subnet "10.0.2.0"

Node connectivity passed for subnet "192.168. (more...)

How Linux Works, 2nd Edition What Every Superuser Should Know by Brian Ward; No Starch Press

Everyone knows about Linux. It's a popular operating system that is the software on a computer that enables applications and the computer operator to access the devices on the computer to perform desired functions.
You can read more on link what I pointed to it. For me, Linux is a great operating system that I can use it as Desktop and Server. I have used it over ten years. It's very interesting operation system. I have (more...)

truncated ddl in 12c (and 11.2.0.4)

Just curious if anyone else is seeing this behaviour..

SQL> set long 500000
SQL> @pt "select * from v$sql where sql_id = '1km492z723vpu'"
 
SQL_TEXT                      : alter table scott.emp
SQL_FULLTEXT                  : alter table scott.emp
SQL_ID                        : 1km492z723vpu
...

Suffice to say, there’s a lot more to that SQL statement, but its lost in v$sql. Once complete, it does appear in full in v$sqlstats, but its a pain when you cant see the whole statement..


Upgrade Oracle GoldenGate 12.1.2.0.x to 12.1.2.1.x

Recently, I’ve been engaged in a conversation on the OTN community pages about upgrading Oracle GoldenGate 12c from 12.1.2.0.0 to the 12.1.2.1.0.  During the discussion I mentioned that you can upgrade using the Oracle Universal Installer (OUI) that is now available with Oracle GoldenGate 12c.  The upgrade process I’m going to show you here is an in-place upgrade of Oracle GoldenGate 12c for Oracle Database 12c.

Note: (more...)