How To Avoid Exadata Cell Node Reboot While Modifying NTP Service

Recently, we had a hardware failure on our NTP server which caused its crash. Due to this, the ntpd daemon on compute nodes and cell nodes went offline. After fixing the hardware issue on NTP server, starting ntpd service using "service ntpd start" on compute nodes was successful but when I started the ntp service…

Storing Date Values As Numbers (The Numbers)

In my last couple of posts, I’ve been discussing how storing date data in a character based column is a really really bad idea. In a follow-up question, I was asked if storing dates in NUMBER format was a better option. The answer is that it’s probably an improvement from storing dates as strings but it’s […]

EM Express Login – Get Flash

I have 12c setup on OEL 6.7 on my VM and while trying to access EM express, I was receiving the error

em_express_error

Just for the notes, a user can log into EM Express using URL

https://<hostname>:<port>/em

and port details can be found using

lsnrctl status | grep HTTP
or  
select dbms_xdb_config.getHttpsPort() from dual;

Clicking on the “Get Flash” takes you to abode flash page from where you can download the rpm for flash.

 (more...)

PREDICTION_DETAILS function in Oracle

When building predictive models the data scientist can spend a large amount of time examining the models produced and how they work and perform on their hold out sample data sets. They do this to understand is the model gives a good general representation of the data and can identify/predict many different scenarios. When the "best" model has been selected then this is typically deployed is some sort of reporting environment, where a list is (more...)

Storing Date Values As Characters Part II (A Better Future)

In the previous post, I discussed how storing date values within a character data type is a really really bad idea and illustrated how the CBO can easily get its costings totally wrong as a result. A function-based date index helped the CBO get the correct costings and protect the integrity of the date data. During […]

Fixed Table x$ktfbue has not statistics

While playing around 12.1.0.2 db, I ran my usual script to check tablespace usage details and it took ~59 secs (Elapsed: 00:00:59.02), which was high.
Ran the sql using “gather_plan_statistics” hint and below lines in the execution plan were of interest –

|  34 |      HASH GROUP BY                     |                    |      1 |      6 |      3 |00:00:58.68 |     129K|  54801 |  1160K|  1160K|  758K (0)|
|  35 |       VIEW                             | DBA_FREE_SPACE      (more...)

INSERT ALL caveat

Why you might want to think twice about using INSERT ALL.

One of those things I knew and then forgot.

So, let’s say you’ve got three tables or a partitioned table or something like that.

Let’s use regional tables for simplicity.

drop table t1_r1;
drop table t1_r2;
drop table t1_r3;

create table t1_r1
(col1 varchar2(2) not null
,col2 number not null
,check( col1 in ('R1')));

create table t1_r2
(col1 varchar2(2) not null
,col2 number not  (more...)

Storing Date Values As Characters (What’s Really Happening)

For something that’s generally considered an extremely bad idea, I’ve lost count of the number of times I’ve come across applications that insist on storing date values as characters within the database. We’ve all seen them … I recently got called in to assist a customer who was having issues with a POC in relation […]

Oracle ASMLib

This blog post is more of a note for myself on configuring ASMLib.

ASMLib is an optional utility that can be used on Linux systems to manage Oracle ASM devices.

ASMLib consists of the following components:

An open source (GPL) kernel module package: kmod-oracleasm
An open source (GPL) utilities package: oracleasm-support
A closed source (proprietary) library package: oracleasmlib

On my Oracle VMBox, I performed the below steps –

1. Check the installed packages related to (more...)

12cR1 RAC Installation on OEL7

To build Oracle Clusterware Database at Home, I believe , RAC ATTACK is the best place to learn. Its is a free curriculum and platform for hands-on learning labs related to Oracle RAC. While reviewing the article, I thought to perform 12cR1 RAC installation on OEL 7.2.

Attached is the document :- 12c_RAC_on_OEL7

The attached article is inspired by

RAC ATTACK :- https://en.wikibooks.org/wiki/RAC_Attack_-_Oracle_Cluster_Database_at_Home/RAC_Attack_12c

Tim Hall’s article :- https://oracle-base.com/articles/12c/oracle-db-12cr1-rac-installation-on-oracle-linux-7-using-virtualbox 

Deploying Oracle RAC (more...)

#GoldenGate #Cloud Service (#GGCS) … what to expect?

As I sit here working on performing some GoldenGate migrations to AWS for a client, I’ve been thinking about the glimpse of GoldenGate Cloud Service (GGCS) that was provided to me earlier this week. That glimpse has helped me define what and how GGCS is going to work within the Oracle Cloud space. Ever since this service was announced back at Oracle Open World 2015, I’ve been wanting to get my hands on this cloud (more...)

Side-effect of ALTER SESSION SET CURRENT_SCHEMA

For most of our database set-ups we use a different TEMP space for application users than for end-user/support/developer/reporting usage.
The intention is to minimise the potential impact of a rogue ad-hoc query on the main applicaiton.

However, turns out this is ineffective IF you use:

ALTER SESSION SET CURRENT_SCHEMA = main_app_schema;

This is documented but I wasn’t previously aware.
No surprise that this learning opportunity was presented as a direct result of a rogue query (more...)

Dead Connection Detection in Oracle Database 12c

In my earlier post I discussed what Dead Connection Detection is and why you should use it – read more here Oracle TNS-12535 and Dead Connection Detection

The pre-12c implementation of DCD used TNS packages to “ping” the client and relied on the underlying TCP stack which sometimes may take longer. Now in 12c this has changed and DCD probes are implemented by TCP Stack. The DCD probes will now use the TCP KEEPALIVE socket (more...)

Veridata and boot.properties file

I’m spending some time building out an Oracle WebLogic/Veridata system at home. This is mostly for testing and general understanding purposes. One of the things I’ve noticed with the WebLogic server requires the username and password before the WebLogic server will start. After providing the name and password, the terminal window has to stay open because, closing it will kill the WebLogic server that is running. This leads to two interesting question and simple resolutions.

(more...)

Oracle TranslationHub neither supported for 12c Database, 12c Forms/Reports or 64 bit!

If you need TranslationHub (Windows only) for your forms and reports development and plan to move to one of the following

  • 12c Database for your TranslationHub repository
  • 12c Forms/Reports (only available for 64 bit Windows)
  • higher version of 64 bit 11g Forms/Reports

then please immediately stop! None of this combination works with TranslationHub!

For the last point I had created enhancement request 14155931 back in June 2012!

For the first point I had created a service request (more...)

#EMd360 … OEM health checks made easy

Oracle Enterprise Manager 12c is a great tool! Now that 13c is out, it is getting even better. This post however it not really about Oracle Enterprise Manager, rather than a quick and simple health check tool that I’ve put together. With the help of of some really cool co-workers (Carlos Sierra and Mauro Pagano), I’ve put together a small diagnostic tool call EMd360.

EMd360 stands for Enterprise Manager d360. The concept behind (more...)

Changing SOA properties via WLST





Hereby a script to change some properties for SOA Suite. These are some generic settings such as:


  • soa-infra
  • AuditLevelGlobalTxMaxRetry
  • DisableCompositeSensors
  • DisableSpringSESensors
  • mediator
  • AuditLevel
  • bpel
  • AuditLevel
  • SyncMaxWaitTime
  • Recovery Schedule Config
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import javax.management.Attribute;
import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.Query;
import javax.management.QueryExp;
import javax.management.openmbean.CompositeDataSupport;
import (more...)

Hello Noida-Are You Attending Oracle Cloud Day….

Are you living and/or working in Noida or any place near to it? Do you happen to work with Oracle technologies especially database and it’s related ones? Are you curious to understand technically about Oracle’s Cloud Computing services? Well, then you must attend,

Oracle Cloud Day 26th March 2016

In a first of it’s kind event happening at Oracle’s Noida office, would be bringing you the information about three different aspects of Oracle’s Cloud services-Oracle (more...)

Hello Noida-Are You Attending Oracle Cloud Day….

Are you living and/or working in Noida or any place near to it? Do you happen to work with Oracle technologies especially database and it’s related ones? Are you curious to understand technically about Oracle’s Cloud Computing services? Well, then you must attend,

Oracle Cloud Day 26th March 2016

In a first of it’s kind event happening at Oracle’s Noida office, would be bringing you the information about three different aspects of Oracle’s Cloud services-Oracle (more...)

Client support for WITH using PL/SQL

My employer has been using 12c for about a year now, migrating away from 11gR2. It's fun working out the new functionality, including wider use of PL/SQL.

In the 'old' world, you had SQL statements that had to include PL/SQL, such as CREATE TRIGGER, PROCEDURE etc). And you had statements that could never include PL/SQL, such as CREATE SYNONYM, CREATE SEQUENCE. DML (SELECT, INSERT, UPDATE, DELETE and MERGE) were in the latter category.

One of (more...)