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Database Feed

Oracle Database, Oracle 10g, Oracle 11g, Oracle XE, Oracle RAC, Oracle Instant Client, Oracle Data Guard and Oracle Exadata resources, news, and support articles.

The Power of the Oracle Database Proxy Authenticated Connections

We recently received this inquiry from a client:

“Can an Oracle database account support two passwords at once so we can roll out updated credentials to application servers gradually rather than having to change them all at the same time? Then once all of the application servers have been configured to use the new/second password we can change or remove the first one?

Log Buffer #394, A Carnival of the Vanities for DBAs

This week’s log buffer edition collects some of the insightful blog posts from Oracle, SQL Server, and MySQL.

Oracle:

Oracle StorageTek T10000D Tape Drive achieves FIPS 140-2 Validation.

Oracle is a Leader in IDC MarketScape for Global Trade Management.

OCP 12C – Oracle Data Redaction

What is Oracle Data Redaction ? Oracle Data Redaction is meant to mask (redact) sensitive data returned from application queries. Oracle Data Redaction doesn’t make change to data on disk, the sensitive data is redacted on the fly before it is returned to the application. You can redact column data by using one of the following methods: Full [...]

North India Chapter Of AIOUG-A Beginning….

I come from North India region of India. Though this part of India is considered to the richest, both in terms of wealth and culture, one thing that it lacks really badly is the awareness about what’s going in the IT world currently! There are just so many colleges and universities but the number of IT companies, doing serious IT work can be counted on fingers of one hand itself. In such situation, awareness about what’s going on the world of Oracle technologies is just so little. And that did bother me for a very long time.

Oracle upgrades MySQL’s capabilities

In the era of big data, database administration services are finding ways to work with NoSQL environments, Hadoop and other solutions. 

Yet, these professionals aren't so quick to write off the capabilities of open source relational databases. When Oracle purchased the rights to distribute MySQL, a few critics were a bit skeptical of the software giant's intentions. Evidently, the company intends to refine and improve MySQL as much as possible. 

First Rows

I received an email earlier on this year asking me my opinion of the first_rows option for the optimizer mode. My correspondent was looking at a database with the following settings:

optimizer_mode=first_rows
_sort_elimination_cost_ratio=4

He felt that first_rows was a very old optimizer instruction that might cause suboptimal execution plans in it’s attempt to avoid blocking operations. As for the cost ratio, no-one seemed to be able to explain why it was there.

Redirect

This blog is currently being redirected to the following URL : BLOG.MORENO-CAMPOS.COM Please replace ocpdba.wordpress.com with the above mentioned.Filed under: Uncategorized

Oracle: an unexpected lock behavior with rollback

Here is an odd behavior I encountered when a transaction that acquired a lock is rolled back. Note that it is related to a specific combination of locks that should not be encountered in production. So it's not a bug. Just something unexpected.
First session
In my first session I lock the DEPT table in share mode (RS)
20:56:56 SQL1> lock table dept in row share mode;
Table(s) Locked.

My first session (SID=53) has acquired a TM lock in mode 2 (row share):

Heuristic TEMP Table Transformation

There are at least three different ways how the Oracle optimizer can come up with a so called TEMP table transformation, that is materializing an intermediate result set:- As part of a star transformation the repeated access to dimensions can be materialized- As part of evaluating GROUPING SETs intermediate result sets can be materialized- Common Subquery/Table Expressions (CTE, WITH clause)Probably the most common usage of the materialization is in conjunction with the WITH clause.This is nothing new but since I came acros

Enable Archivelog mode on Oracle11g R2 RAC environment

Today I want to show you how to enable archivelog mode on Oracle 11g R2 RAC environment.1. Checking log_mode:http://2.bp.blogspot.com/_z5ltvMQPaa8/SjJXr_U2YBI/AAAAAAAAAAM/46OqEP32CJ...) rgb(240, 240, 240); border: 1px dashed rgb(204, 204, 204); font-family: arial; font-size: 12px; height: auto; line-height: 20px; overflow: auto; padding: 0px; width: 450.828125px;"> [oracle@rac1 acfs]$ export ORACLE_SID=RAC1 [oracle@rac1 acfs]$ sqlplus "/as sysdba" SQL> archive log list

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