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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.

“alter session force parallel query”, and indexes

This post is a brief discussion about the advantages of activating parallelism by altering the session environment instead of using the alternative ways (hints, DDL). The latter ways are the most popular in my experience, but I have noticed that their popularity is actually due, quite frequently, more to imperfect understanding rather than informed decision - and that's a pity since "alter session force parallel query" can really save everyone a lot of tedious work and improve maintainability a great deal.

We will also check that issuing

Recover corrupted blocks using Flashback Logs

Starting with 11g Oracle can perform block media recovery using flashback logs to get good copies of the blocks.

Flashback database is not enabled by default so first step would be to enable it. When enabled a process RVWR (Recovery Writer) copies modified blocks to flashback buffer. Later this buffer is flushed to disk (flashback logs). It is important to notice that flashback logging is not getting log of a changes but complete block images.

Enable flashback database.

EM12c - A Step Backwards?

Enterprise Manager Cloud Control 12c is mostly a better product than the 10g version we were using before.  But I am getting really frustrated with the Explain Plan functionality.

A big part of my job is performance tuning and monitoring running SQL.  And to do that you need a clear, quick, stable view of the query plan, along with all pertinent information, such as the total cost of the plan.  in EM10g, we had that.

EM12c, though, is a huge step backwards.

Specifically:

IT security an increasingly top challenge and focus for enterprises

With the emergence of IT trends such as cloud computing and mobility, enterprises have realized that previous security efforts are inadequate for mitigating the new risks that come with these technologies. While looking to upgrade the security infrastructure, firms are may need remote database support to ensure improvements in data protection.

Conditional Unique Indexes


Matrix : What you must learn is that these rules are no different than rules of a computer system. Some of them can be bent, others can be broken. Understand?

play with vncserver... when it showed nothing

I often use "ssvnc" to connect my servers to install or do something about X. Anyway, I must to start VNC before by using "vncserver".

[surachart@oralearning ~]$ vncserver

New 'oralearning:1 (surachart)' desktop is oralearning:1

Starting applications specified in /home/surachart/.vnc/xstartup
Log file is /home/surachart/.vnc/oralearning:1.log

[surachart@oralearning ~]$

I ended up find nothing when I connected VNC as below picture.

Using Apex with IIS Express

The Thoth Gateway is a gateway written in C# and ASP.NET that allows you to run PL/SQL web applications (including Oracle Application Express) on Microsoft's Internet Information Server (IIS). You can read more about the gateway here. It is an alternative to Apache/mod_plsql and the Java-based Apex Listener.

Linux large pages and non-uniform memory distribution

In my last post about large pages in 11.2.0.3 I promised a little more background information on how large pages and NUMA are related.

Background and some history about processor architecture

APEX Easter fun

This isn't really an easter egg, just more of a mild bug that makes you think - hopefully a little more about your own applications.

If you type in "0" in the page navigation bar, it takes you to the typical global page / page zero for desktop.
Instead of displaying page processing and shared components, it displays application level components - items, process, computations; and an "About" region in the third column, above recently edited pages. Useful stuff...

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