What keeps database administrators awake at night and the search for the promised land

What keeps you and me awake at night? When I was a consultant for a Fortune 500 company in Southern California, we were getting beaten up to prove that databases were being backed up correctly and that disaster recovery would work. The truth of the matter was that we didn’t even have an accurate list of all the databases and databases would go down for days without anybody noticing which means that they were not (more...)

What Dr. Edgar Codd said about the relational model in 1981

Dr. Edgar Codd introduced the relational model in his 1970 paper “A Relational Model of Data for Large Shared Data Banks”—there was an earlier 1969 version but let’s not digress. The 1970 paper was reprinted in the 25th anniversary edition of the NoCOUG Journal. It’s terribly mathematical and consequently not very comprehensible to mere mortals. But his 1981 ACM Turing Award lecture is a study in contrast so I recommend it highly. You can read (more...)

Guest lecture on Database Performance

A few weeks ago I got an invitation to give a guest lecture at the "AP Hogeschool" in Antwerp about "Database Performance".
I've already presented on conferences and teached some courses, but until now only for professionals. This would be the first time for students.

It would be for the "Software Engineering" course of 2nd year bachelor degree IT.
The students already learned about the Oracle database and should know SQL and PL/SQL.

OTN ACE Director APAC Tour in Sydney Sessions

Uncategorized
| Oct 31, 2016
Thank you all for coming to my sessions at the Sydney conference of Oracle Technology Network +Oracle Community Network ACE Directors Tour in APAC. Please feel free to download the materials presented.




1. Secure your database in 1 day Presentation and Scripts
2. Prevent Bad SQLs in the Cloud Presentation
3. Becoming a Multitenant DBA Presentation




As always, I will appreciate to hear from you how you "really" felt about them--the good , the bad (more...)

The Little User Group That Could

NoCOUG is “the little user group that could!” As you might imagine, it requires a vast amount of work to organize a full-day users group conference and publish a printed journal every quarter. No sooner has a conference ended and a journal mailed than it is time to start work on the next conference and the next journal. But the awesome NoCOUG volunteers have pulled it off—quarter after quarter—for 30 long years. The upcoming (more...)

The most inventive thing I’ve done

The most inventive thing I’ve done is a software program that I wrote for my first employer almost 30 years ago. I was a fresh-faced COBOL programmer for a software company in Bombay (now Mumbai) which had won a turnkey contract to write hundreds of COBOL reports for the very first computerization effort of the Department of Banking Operations and Development (DBOD) of the Reserve Bank of India. The report layouts had been designed by (more...)

ORA-01157: cannot identify ORA-01110: data file with dba_temp_file

                                 Recently one of our database was migrated. After migration DB is up and running, But we found below errors in the alert log.

 

Errors in file /oracle/app/oracle/admin/test/diag/rdbms/b2btrn/TEST/trace/test_ora_20464.trc:
ORA-01157: cannot identify/lock data file 205 – see DBWR trace file
ORA-01110: data file 205: ‘/test/oradata/b2btrn/tempfile/temp1.304.921456819′

Now I queried dba_temp_files, and got the same error.

 

SQL> select (more...)

ORA-38301: can not perform DDL/DML over objects in Recycle Bin

           While dropping a tablespace, getting error ORA-38301: can not perform DDL/DML over objects in Recycle Bin .

SQL> drop tablespace DATA including contents and datafiles;
drop tablespace DATA including contents and datafiles
*
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-38301: can not perform DDL/DML over objects in Recycle Bin

 

Solution:

Before dropping the tablespace, disable recyclbin . 

1. Disable recyclebin:

SQL> ALTER SYSTEM SET recyclebin (more...)

Blogs to read in the Oracle DBA/Developer world

:Earlier this month, I conducted a totally unscientific survey on Twitter, asking where people got their Oracle news from. Twitter and the NoCOUG Journal were two popular sources, along with a wide range of blogs. Here are some of the blogs that the Oracle DBA & Dev superstars in my Twitter like to read:

"ORA-20001: Application ID and current security group ID are not consistent" encountered during APEX Upgrade from 4.x to 5.x

Recently, our QA team at Oracle was testing database upgrades, and the following error appeared in the database upgrade log while the APEX component was being upgraded:

...Installing Theme 1

API Last Extended:20130101
Your Current Version:20130101
This import is compatible with version: 20130101
COMPATIBLE (You should be able to run this import without issues.)
--application/set_environment
APPLICATION 108801 - Theme: Simple Red
--application/delete_application
begin
*
ERROR at line 1:
ORA-20001: Application ID and current security (more...)

Connecting PL/SQL Developer

In SQL Developer you have a lot of options when connecting to the database. You can use the TNS entries defined but you can also give the hostname, port and SID or Servicename for instance. PL/SQL Developer doesn’t supply these options, but you can still use them…

In the logonscreen you can choose the database by choosing you TNS entry. But did you know you can put in the complete text of a tnsnames.ora (more...)

Exadata memory configuration

Read this post if your Exadata compute nodes have 512/768GB of RAM or you plan to upgrade to the same.

There has been a lot of information about hugepages and I wouldn’t go into too much details. For efficiency, the (x86) CPU allocates RAM by chunks (pages) of 4K bytes and those pages can be swapped to disk. For example, if your SGA allocates 32GB this will take 8388608 pages and given that Page Table (more...)

OTN APAC Tour Wellington, New Zeland Sessions

Uncategorized
| Oct 25, 2016
Thank you all for coming to my sessions. I understand your time was important and I appreciate your taking the time to spend the time listening to me.






Here are the materials for my sessions:






1. Cross Platform Database Migration Using RMAN Slides
2. The Art and Craft of Tracing Slides, Scripts
3. Big Data for Oracle Professionals Slides






Like always, I would love to hear form you, not just that you liked something; (more...)

OTN APAC Tour Auckland Sessions

Uncategorized
| Oct 25, 2016
Thank you all for coming to my sessions. I understand your time was important and I appreciate your taking the time to spend the time listening to me.






Here are the materials for my sessions:






1. Cross Platform Database Migration Using RMAN Slides
2. The Art and Craft of Tracing Slides, Scripts
3. Big Data for Oracle Professionals Slides






Like always, I would love to hear form you, not just that you liked something; (more...)

WS Security – enabling passwordDigest authentication in an Oracle FMW environment

Objective:
To have a basic level of authentication on web services (especially where there's no transport layer security) without having to pass clear text passwords in the WS Security headers. 

Background:
The concepts are fairly generic but this post is highly Oracle Fusion middleware specific. There can be complex decision tree (see [1]) involved when selecting the 'appropriate' level of security for any system. As security involves trade-offs between cost, performance, usability (more...)

Managing shared metadata (MDS) in a CI enviornment

Goals and Summary:
* Package shared metadata in a SOA environment and make it widely distributable (SOA MDS [2], Servicebus, maven artifact repository) 
* Associated sample: https://github.com/jvsingh/SOATestingWithCitrus/tree/develop/shared-metadata  
* Key command (if you use the associated pom file) 
mvn deploy com.oracle.soa.plugin:oracle-soa-plugin:12.2.1-0-0:deploy -Dpassword=*****

       
Background:
Having worked on a wide range of projects, I came to the realisation that SOA can mean vastly different things in different (more...)

PLS-00801: internal error [hshuid:LU invalid] when compiling a package body

This was a strange one.  Attempts at recompiling the following package body resulted in this PLS-00801 error. COL owner FOR A20 COL object_name FOR A40 BREAK ON object_name SELECT owner, object_name, object_type, status, created, last_ddl_time FROM dba_objects WHERE object_name = 'PKG_FINANCIALS_WORK' ORDER BY status, object_type / OWNER                OBJECT_NAME    

Read More...

Cloud to Ground Mashup Webinar

At 11:00 AM Pacific on Tuesday, October 25th (tomorrow), I have the privilege of talking about Cloud and on-premise (ground) integration. Whether cloud to cloud, cloud to ground, or ground to ground, integration is probably one of the most difficult aspects of any implementation. Integration comes in two flavors:

  • Back-end
  • Front-end

Back-end integration is the most common. Back-end integration involves integrating data between two systems either for processing or presenting a common user experience.

Front-end (more...)

HotSpot JVM garbage collection options cheat sheet (v4)

After three years, I have decided to update my GC cheat sheet.

New version finally includes G1 options, thankfully there are not very many of them. There are also few useful options introduced to CMS including parallel inital mark and initiating concurrent cycles by timer.

Finally, I made separate cheat sheet versions for Java 7 and Java 8.

Below are links to PDF versions

Speaking at APAC OTN TOUR 2016 in Wellington, New Zealand

The APAC OTN Tour 2016 will be running from October 26th until November 11th visiting 4 countries/7 Cities in the Asia Pacific Region.

I will be speaking at APAC OTN TOUR 2016 in Wellington, New Zealand on 26th October on the topic which is very near and dear to me; Exadata and Cloud.

My session is 12c Multi-Tenancy and Exadata IORM: An Ideal Cloud Based Resource Management with Fahd Mirza

Hope to see you there !