Oracle Virtualization and Cloud Consulting
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Another example of GATHER_TABLE_STATS and a Histogram

In response to a forum thread "Why not selecting index path .", I ran up this example :

SQL> select banner from v$version where rownum=1;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production

SQL>
SQL> drop table test_index_count5 purge;

Table dropped.

SQL> alter system flush shared_pool;

System altered.

Oracle Android App

Yesterday, I downloaded and installed the Oracle Android App onto my Samsung Galaxy S phone.
I must say : the App provides a quick overview of what's happening in the Oracle World.
It is certainly much faster and better organised than the FaceBook App.
It provides listings of news updates and a few blog posts.

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An Index that is a "subset" of a pre-existing Index

It is a common [mis]understanding that creating a new Index that is a subset of an existing Index is an unnecessary overhead. The argument goes "if you have an Index on (A,B,C) this Index can be used to satisfy queries where predicate 'A' is specified, so creating an additional Index on (A) alone is an unnecessary overhead".

Oracle Database Architect Position at SCB

See Oracle Database Architect Position at SCB

DO NOT send me your emails / resumes. Please follow the instructions given in the advertisement.
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RMAN Tips -- 2

Incremental Backup from a particular SCN

RMAN allows you to take an Incremental Backup "FROM SCN". Why ? For the purpose of updating a Standby Database.


[oracle@localhost ~]$ sqlplus '/ as sysdba'

SQL*Plus: Release 11.2.0.1.0 Production on Tue Sep 20 23:35:38 2011

Copyright (c) 1982, 2009, Oracle. All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

Very successful Golden Gate workshop at SG RACSIG

Jigar led the Singapore RACSIG Golden Gate workshop very well today. It was quite apparent that he knows the product well and is enthusiastic about sharing his knowledge.
Ravi also added a few observations and asked "review questions" of the members present.

Thank you very much Jigar.
Thank you Ravi.

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RMAN Tips -- 1

Restoring ArchiveLogs to an alternate location


RMAN> list archivelog all;

specification does not match any archived log in the repository

RMAN> sql 'alter system switch logfile';

sql statement: alter system switch logfile

RMAN> list archivelog all;

List of Archived Log Copies for database with db_unique_name ORCL
=====================================================================

Key Thrd Seq S Low Time
------- ---- ------- - ---------
806 1 237 A 11-SEP-11

Outer Join Queries

Outer Join queries are difficult to understand initially. Effectively, an Outer Join query allows the developer to create dummy rows (with NULLs for the returned columns) for a table when a join to another table would fail. Thus, the developer can see rows in the other table for which there are no corresponding entries in the "join failed" table.

Splitting a Range Partitioned Table

Here's a simple demonstration of splitting a Range Partitioned Table :


SQL> --- Create a Table with a MAXVALUE partition
SQL> drop table sales purge;

Table dropped.

SQL> create table sales
2 (order_id number not null,
3 sale_date date,
4 cust_id number,
5 prod_id number,
6 remarks varchar2(128))
7 partition by range (sale_date)
8 (partition P_2007 values less than (to_date('01-JAN-2008')),

Understanding Obsolescence of RMAN Backups

Questions about the the LIST OBSOLETE command keep appearing in RMAN forums.

Given this configuration :

RMAN> show all;


RMAN configuration parameters for database with db_unique_name ORCL are:
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 15 DAYS;
CONFIGURE BACKUP OPTIMIZATION OFF;
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET;
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