Posts

    [ + | - ]

Archives

    [ + | - ]

Resource Pages

    [ + | - ]

Welcome to Oracle Masters. The portal, as the tagline says, is for anything Oracle. FAQs, Certifications, Resources! In addtion, there will be pages on real life scenarios, Oracle internals, approaching the DBA job at various stages in your career and many other useful resources.Further, if you have a question, you can ask it and we will answer it at the earliest!
So join in. Learn, share and prosper!
Register with us!





Ramesh Menon
Oracle Certified Master - 10g
Oracle Certified RAC Expert - 10g
Oracle Certified Professional - 11g

Are you interested in Weekend/Online Training in Oracle DBA? Do you have business/consulting requirements? Click here Enquiry Form to leave your requirements or mail me at Ramesh Menon

Backup/Recovery andVideos
Sunday, 22 Mar 2009 6:05 AM

Rman Catalog Setup – Video

By Ramesh Menon Ramesh Menon

Tutorial Difficulty : Very Low, Fundamentals
In this tutorial, I explain the fundamental method of creating a RMAN catalog, registration of a database and backup of a database.

I have used trial software to create the tutorial, hence please excuse the watermark etc. I will soon be purchasing the full version of some tool for this task.

Popularity: 11% [?]

Unix for DBAs
Saturday, 21 Mar 2009 2:13 AM

Create Raw partitions on Linux (Redhat Build)

By Ramesh Menon Ramesh Menon

Oracle allows the use of raw files in a lot of scenarios. You can setup your datafiles and redo log files are raw files. ASM too, uses raw files to build disk groups. This document, like many others, shows you how you can create raw files on Linux (CentOS). This will work with Redhat linux too.

Read the rest of this entry »

Popularity: 5% [?]

Uncategorized
Monday, 16 Mar 2009 5:21 AM

Fixing a corrupt Oracle Inventory

By Ashok Tawde Ashok Tawde
The Oracle Inventory is a critical part of oracle installation. We need this to find out what patches have been applied, mostly during upgrades and patch applications.

Some times, this location can become corrupt and this will hamper the operations.
In this short article, we will show you how we can fix a corrupted oracle inventory.

Read the rest of this entry »

Popularity: 27% [?]

Architecture andArchitecture FAQs
Friday, 6 Mar 2009 7:50 AM

About temporary and undo tablespace

By srini Srinivasan Viswanathan

Srinivasan Asked:
What is the actual difference between temporay table space & undo table space?

Temporary tablespaces
Read the rest of this entry »

Popularity: 10% [?]

Architecture
Wednesday, 4 Mar 2009 1:27 AM

What are Version enabled tables?

By Ruxina Ruxina Lopes

Ruxina asked: What are version enabled tables?

Answer: Version enabled tables allow users enables them to maintain multiple versions of a row in that table. Oracle provides the enableversioning procedure in the the dbms_wm package. Oracle internally creates objects based on the table and renames the version enabled table with a suffix of _LT.

Read the rest of this entry »

Popularity: 6% [?]

Architecture
Monday, 16 Feb 2009 11:02 PM

Data files

By Ramesh Menon Ramesh Menon
This entry is part 5 of 5 in the series Oracle Database Concepts

Datafiles are physical files that are part of the database. All data of the database (except those of external tables) are stored
on these datafiles.

One or more datafiles, are logically grouped into logical units called tablespaces. A datafile can be associated with one and only one tablespace.

Just as tablespaces are a higher logical group, the data files are logically made up of blocks (the lowest granularity), extents (made up of blocks) and segments (made up of extents).

Example of segments are data segments, index segments, etc.

Oracle allows the DBA to specify various storage parameters while creating datafiles.

Examples of datafiles…

sql> create tablespace mytbs datafile ‘/u02/oradata/PROD/mytbs01.dbf’ size 100M;

sql> alter datablespace mytbs
add datafile ‘/u02/oradata/PROD/mytbs02.dbf’ size 100M;

Popularity: 6% [?]

Architecture
Monday, 16 Feb 2009 1:43 AM

Oracle Database Concepts

By Ramesh Menon Ramesh Menon
This entry is part 1 of 5 in the series Oracle Database Concepts
  1. What is an Oracle database?

    2. Oracle database comprises of a set of physical files stored on disks. These files could be of the following types

    The database also has a logical structure. The datafiles and temporary files are grouped together to form the logical structures of the database. Read the rest of this entry »

Popularity: 4% [?]

Architecture
Sunday, 8 Feb 2009 1:30 AM

Dead Locks – Concept & Simulation

By Ritesh Kumar Singh Ritesh Kumar Singh
  • What is a dead lock?

    • A deadlock occurs when two or more session are waiting for data locked by each other, resulting in all the sessions being blocked.
    Oracle automatically detects and resolves deadlocks by rolling back the statement associated with the transaction that detects the deadlock.
    Typically, deadlocks are caused by poorly implemented locking in application code. This is also stated in the Oracle trace file as shown in later part of this article.

  • Dead lock simulation

    • Consider the table EMP where there are 2 employees FORD (empno 7902) and MILLER (empno 7934).
    Two HR employees, Rony and Bony are trying to update the commission of these employees from different sessions (Rony’s session 1 = 139 and Bony’s session 2 = 131)
    The order of update is as follows
    Rony Updates FORD’s commission — No issues as common rows are not updated
    Bonny Updates MILLER’s commission — No issues as common rows are not updated
    Rony Updates MILLER’s commission — Waiting for Bonny’s session to complete
    Bonny Updates FORD’s commission — Waiting for Rony’s session to complete
    Read the rest of this entry »

Popularity: 8% [?]

Uncategorized
Saturday, 31 Jan 2009 9:01 AM

Redo Log Files

By Ramesh Menon Ramesh Menon
This entry is part 4 of 5 in the series Oracle Database Concepts
  • What is a redo log file?

    • Oracle records all changes made to the database in files called redo log files. These changes contain both committed and uncommitted data (after image).
    Every instance that accesses the database needs these crucial files, in order to prevent data loss in case of instance failure.

  • Key terms for redo logs

    • Read the rest of this entry »

Popularity: 6% [?]

Architecture
Friday, 30 Jan 2009 10:46 PM

Control Files

By Ramesh Menon Ramesh Menon
This entry is part 3 of 5 in the series Oracle Database Concepts
  • What is a Controlfile

    • A control file is a binary file which is part of the database. The instance accesses this file during startup as well as during normal operations of the database.
    Read the rest of this entry »

Popularity: 3% [?]

Control Panel

Login



My Links

Blogroll

Project Management

Recent Posts

Recent Comments
Internet Advertisingundelete