Blocking Prepared XA Transaction

There was an oracle-l thread last month about blocking sessions which could not be identified.

I replied back about a very niche scenario which I’d seen a few times before. And it’s just happened again so I thought it would be useful to just post some evidence on this.

Here are a couple of articles posted previously on XA transactions:

First, a reminder, from the posts (more...)

ORA-4031 Troubleshooting – Issue with durations in 11gR2

I recently had to troubleshoot an ORA-4031 issue at a client site. The issue reappeared 3 times within 2 months and only after escalating the SR to SEV1 and being quite persistent for an explanation, the second engineer attempting to solve the issue finally got it right.  Being curious, I digged into the trace files again to confirm and understand the issue here. This blog post describes the method to analyze the issue and (more...)

“#PL/SQL: Therefore, whoever binds forever: automate your tests” – I’m a speaker at #DOAG2017

 

Today my presentation is confirmed: “Therefore, whoever binds forever: automate your tests”. Maybe the German pun will be the better understood: “PL/SQL: Drum test-automatisiere, wer sich sich ewig bindet!”

I will speak over my experiences with following

  • several PL/SQL testing tools like at least
  • I will give you a demo of this tools and compare their capabilities for
    • architecture
    • branching
    • continuous integration
    • code coverage

If you (more...)

12cR2 tightens up ORA-01841 for zero year ANSI dates, but not for Oracle SQL syntax

In moving some more code from an 11gR2 database to a 12cR2 database, I found another change where a piece of code that works in 11gR2 doesn’t compile in 12cR2.

In this instance a view was being created with a projected date column which used the ANSI DATE syntax. Here is a simplified test script:

CREATE OR REPLACE VIEW test1 AS
SELECT date '0000-01-01' date_col
FROM dual
/
DROP VIEW test
/

CREATE OR REPLACE  (more...)

Virtual Development Server: Provide Docker images in docker registry for Oracle XE Database and others

For later creation of containers as needed in the deployment process we have first to build docker images whenever we do not find suitable one in docker hub.

For most of my development I need a oracle database. On the internet you can find a lot of Dockerfile’s for this, but no ready image. This is because for running a database you have to accept a license and this happens when you download the installation (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...)

PROCESSED Messages not clearing from Oracle Queue

I was contacted by Dev team to look into Development database where Oracle queue size kept  on increasing. As per them messages were not getting cleared.They were running count on Queue table and the count kept increasing. To find out exact cause I included the msg_state in the query and found out that there were…

APEX 5.0 Beyond basics

iAdvise presented the APEX 5.0 roadshows in the first half of 2015. Besides the presentation about the new features, we provided 3 tutorials which helped the visitors to explore Oracle Application Express 5.0. Now we offer these tutorials through our blog. In this article the second tutorial is presented.

This tutorial helps you step by step through the process of migrating an application to the Universal Theme of Oracle Application Express 5.0. In this tutorial we talk about (more...)

ORA-01873 error running SAP pre-upgrade scripts

While trying to run pre_upgrade_status.sql script for DB upgrade (10.2.0.4 to 11.2.0.4), we got following error @pre_upgrade_status.sql ERROR at line 1: ORA-01873: the leading precision of the interval is too small ORA-06512: at line 8 On debugging further , found out that it was due to limit imposed on "INTERVAL DAY TO SECOND" datatype. By…

LGWR terminating instance due to error 338

Recently we came across a issue where our DB crashed with ORA-00338 error . Errors in file /oracle/diag/rdbms/orcl11g/orc11g/trace/orc11g_lgwr_24118.trc: ORA-00338: log 2 of thread 1 is more recent than control file ORA-00312: online log 2 thread 1: '/oracle/oradata/orcl11g/redo02.log' LGWR (ospid: 24118): terminating the instance due to error 338 DB couldn't be restarted as it gave same errors…

Permissions for both HDFS and local fileSystem paths

| Jul 18, 2014

Hi All,

Permission issues is one of the key error , while setting up Hadoop Cluster, while debugging some error found below table on http://hadoop.apache.org/ . It’s a good scorecard to keep handy.

 

Permissions for both HDFS and local fileSystem paths

The following table lists various paths on HDFS and local filesystems (on all nodes) and recommended permissions:

Filesystem Path User:Group Permissions
local dfs.namenode.name.dir hdfs:hadoop drwx——
local dfs.datanode.data.dir (more...)

Rolling upgrads using logical standby database.

Couple of weeks ago there was a Twitter discussion started by Martin Bach (@MartinDBA) about cases for logical standby implementation. A rolling upgrade was mentioned by Tim Gorman (@timothyjgormanas) as one of potential recommendations for using this rare use product. I have been involved in such project in the past and I prepared an instruction and did quite large number of rolling upgrades from 11.1 into 11.2.

There are couple of my “gotchas”

Oracle Direct NFS and Infiniband: A Less-Than-Perfect Match

Readers of an earlier post on this blog will know about my latest forays into the world of Direct NFS. Part of that means stumbling over configuration hiccups or slamming into brick walls when you find new bugs.

To quickly re-set the table, my organization purchased the Oracle ZFS Storage Appliance (ZFSSA) 7420. Oracle sold us on the Infiniband connectivity as a way to make a possible future transition to Exadata easier. However the pre-sales (more...)

Best of Oracle Security 2013

I just uploaded my DOAG 2013 presentation “Best of Oracle Security 2013“.

 

This presentation shows how to bypass Oracle Data Redaction, become DBA using CREATE ANY INDEX, Hide information from Oracle Auding using VPD and more…

—————————————————

SQL> select * from scott.credit_card where 1=ordsys.ord_dicom.getmappingxpath((card_id),user,user);

(more...)

Decrypt Oracle 11.2.0.3 and 12.1.0.1 database link passwords

At Derbycon 3.0, László Tóth and Ferenc Spala  gave a a new presentation “What’s common in Oracle and Samsung? They tried to think differently… ” (Video). The main focus of the presentation was the Samsung encryption and a new framework called sandy but there was also a small (more...)

BI Mobile HD App 11.1.1.7

Finally got around to writing my long overdue post on the new BI Mobile HD app. To get on with it, without much ado, not to loiter, and all that... here goes.

The new BI Mobile HD app, version 11.1.1.7.0.2094, can be downloaded from the Apple iTunes App Store (link to app preview page on iTunes).
If you already have the BI Mobile HD app installed on your iOS (more...)

Fix for oradebug disable auditing available (11.2.0.3/11.2.0.4/12.1.0.1)

2 days ago I gave a presentation “Oracle 12c from the attackers perspective” at the DOAG SIG Security. I learned some interesting things, especially that a fix for the Oracle oradebug “disable auditing” problem is available since 9 months.

Oradebug allows to run OS commands and to enable/disable Oracle SYSDBA (more...)

portmap: unrecognized service on RHEL6

Original Post can be viewed at portmap: unrecognized service on RHEL6

Quick note for people using NFS for shared storage on RAC database. Till RHEL5 we had to ensure nfs,nfslock and portmap service has to be running. These services are required otherwise you will get following errors while mounting database

(more...)

cursor: pin S wait on X

Original Post can be viewed at cursor: pin S wait on X

Few weeks back thread came up on oracle-l freelist regarding ”cursor: pin S wait on X” event . Tanel Poder replied to this thread with excellent explanation. You can read full thread here

 

This wait happens when your (more...)

Oracle Database Gateways 11g R2 (11.2) Installation and Configuration for heterogeneous connection from Oracle to Microsoft SQL database

Installation

Install the Oracle Database Gateways 11g R2 (11.2). See the screen snapshots of the installation here.

Configuration

  • During the installation, the following+ default initialization parameter file is created:
[ORACLE_DG_HOME]dg4msqladmininitdg4msql.ora
dg4msql = Database gateway for Microsoft SQL Server. 
If you choose a different database option, use the appropriate path name.
  • Copy initdg4msql.ora to a new file init[MSSQL].ora.
[MSSQL] can be any meaningful name easier to refer to,  (more...)