Oracle Exadata Performance: Latest Improvements and Less Known Features

Here are the slides of a presentation I did at the IOUG Virtual Exadata conference in February. I’m explaining the basics of some new Oracle 12c things related to Exadata, plus current latest cellsrv improvements like Columnar Flash Cache and IO skipping for Min/Max retrieval using Storage Indexes:

Note that Christian Antognini and Roger MacNicol have written separate articles about some new features:

Enjoy!

 

Oracle system V shared memory indicated deleted

This article is written with examples taken from an (virtualised) Oracle Linux 6u6 X86_64 operating system, and Oracle database version 12.1.0.2.1. However, I think the same behaviour is true for Oracle 11 and 10 and earlier versions.

Probably most readers of this blog are aware that a “map” of mapped memory for a process exists for every process in /proc, in a pseudo file called “maps”. If I want to look (more...)

OT: A software tool that improves my writing

I would like a little more help with my writing than the Spelling & Grammar check in Microsoft Word can provide so I am checking out a tool called Word Rake.(read more)

Setting up SQL Developer with Instant Client on MacOSX

Since I started a new job I also wanted to try out MacBook as my new laptop. I've never been a Mac user, but there seems to be a large group of people who think Macs are the best, so I needed to find out the goodness of Macs myself :) A quick tip: Don't upgrade to Yosemite if you laptop is bound to Active Directory.

One part of setting up my new laptop was (more...)

What’s this ‘WHERE 1=1′?

Since some time I have been adding WHERE 1=1 to all my queries.
I get queries like this:

SELECT *
  FROM emp e
 WHERE 1=1
   AND e.ename LIKE 'A%'
   AND e.deptno = 20

Lots of people ask me what’s the use of this WHERE 1=1.

You know I like to type as little as possible but here I am typing a lot of extra characters. And yet, it makes my development life a (more...)

SQLTXPLAIN and the AWR Warehouse, Part I

Yeah, so I did it-  I installed SQLTXPLAIN, (SQLT) on the AWR Warehouse!  From previous experience with this fantastic tool, I was pretty sure I’d have some great new adventures with the AWR Warehouse data and I wanted to see if it was something that I could get running with the AWR Warehouse.  This is a work in progress, so I’m going to do this blog in multiple parts to ensure we don’t miss (more...)

SQL Developer 3 and Timestamp Conversion

I shouldn’t be using an old version of SQL Developer like v3 (3.2.10.09) anyway but… cut a long story short … I am.
I’ve also got v4 which doesn’t display the same problem

Just pointing out an oddity whilst investigating something for someone:

with x as 
(select to_date('28-MAR-2015 01:30','DD-MON-YYYY HH24:MI') dt1
 ,      to_date('29-MAR-2015 01:30','DD-MON-YYYY HH24:MI') dt2
 from   dual)
select sessiontimezone
,      dt2 "date"
,      cast(dt2 as timestamp) "timestamp"
,      to_Char(cast(dt2 as timestamp),'DD-MON-YYYY  (more...)

Sequences – where did the view go?

I was pottering around with the sequence cache recently, investigating a few things like exactly when it refreshes (such as if it is flushed or aged from the shared pool – pin it!) and I was monitoring the next value using V$_SEQUENCE, like I have been since, erm, Oracle 8i in 1999 or summit.

I happened to log into an Oracle 12.1.0.2 DB for a check-test and it was empty! My (more...)

5 Things I wish I knew about APEX when I just started (part 2)

In my first post of this series, I talked about subscriptions. The next post in this series is about cookie sharing in APEX, I hope you enjoy it.

Apex SSO by Cookie sharing

In the spirit of the previous post, this post will also be one that comes in handy when running multiple applications in the same workspace. When running multiple applications in the same workspace, it’s possible to share the authentication across multiple applications (more...)

Use a #db12c PDB for the #em12c OMR…Finally

In an earlier post, I mentioned that Oracle has finally, offcially supported the Oracle Management Repository (OMR) on Database 12c (12.1.0.2).  As I’ve been working on a DBaaS project, I built a new Oracle Enterprise Manager (OEM) enivornment to test out a few things.  Since I was rebuilding, I decided to try out the PDB as an OMR (afterall I’ve been asking about this approach).  In the past, installation would fail around (more...)

Better Data Modeling: The Book

Trying to be as productive as possible during my infrequent down time, I just published another Kindle book with some of my best tips for Oracle Data Modeler. it is called Better Data Modeling: Tips for Enhancing Your Use of Oracle SQL Developer Data Modeler. If you are one of the 3.5 million users (or […]

Tablespace HWM

The following question appeared the Oracle-L list-server recently:

In order to resize a datafile to release space at the end, we need to find whatever the last block_id that is at the start of that free contiguous space.
Problem is that we have a very large database such that querying dba_extents to find the last block is probably not an option. The standard query(ies) that make use of dba_extents runs for hours at stretch and also  (more...)

Getting sql statements out of a trace file

The focus on this post started off in one direction and ended up in another. Originally I had been running a drop user script which had hung and even when I killed the process I could not drop the users as it gave a “ORA-01940: cannot drop a user that is currently connected” – despite the users having left the company months ago and there being no chance of them actually having connected sessions. My (more...)

HEUG Alliance 15 – What Looks Good To Me

The Higher Education User Group's Alliance 15 software conference kicks off this Sunday, March 15, in Nashville, Tennessee.  You're going, right?

I'm flying early this weekend myself.  Just have a few conference things to do to get ready for my little role in this big Oracle user group conference.


Looks to be a great conference.  I'm personally planning to dive into five areas of focus:  


  1. increasing my depth of understanding about customers and processes (more...)

Hackathon Provides Opportunity for Collaboration and Innovation

Fishbowl team members competed in our third annual Hackathon over the weekend. Our consultants split up into four groups to create an innovative solution, and were given just over 24 hours to complete the task. The goal was to create usable software that could be used in the future when working with clients; some of our most creative products and services originally derived from Hackathon events.

13689_10152683472083053_3545144700959488753_n  10410948_10152683472493053_2066307430651186573_n

10592750_10152683472058053_6810123916371611080_n  11043146_10152683472098053_5907236575559895437_n

 

Here’s a summary of what the (more...)

Nashville Cat

Nashville cats, play clean as country water
Nashville cats, play wild as mountain dew
Nashville cats, been playin' since they's babies
Nashville cats, get work before they're two

            - From the Lovin' Spoonful's Nashville Cats

I'm heading out to HEUG's Alliance this weekend.  Gonna be a Nashville Cat for a few days.  My big job is to host three workshop/demo sessions on Oracle Cloud Applications, all in Room Delta (more...)

Visualizing Statspack Performance Data in SQL Developer

If you run Oracle Standard Edition or haven’t licenced Diagnostics Pack for Enterprise Edition, then you don’t have AWR and ASH Data available. This is when Statspack, the predecessor of AWR, comes in handy to keep a history of database performance metrics. But although Oracle still deliver Statspack with their recent DB releases (yes, even in […]

The Best Thing

I'm spending the latter part of my week at the Utah Oracle User Group Training Days conference.  It's a nice regional conference for me to engage with...it's local to me here in Salt Lake City.  So I get to participate in the conference and still go home every night.  Pretty sweet.

But being local is not the best thing about this conference.  The best thing about this...or most user group conferences, for that (more...)

Optimizer statistics – Gathering Statistics and Histograms

It’s such a mess with those histograms and statistics that I had to rewrite this post at least ten times. It’s such a mess that I still cannot believe how poorly maintained the global statistics are and how badly created the histograms are. Because of this mess and the depth of the topic this post […]

Tablespace growth history

Recently we had a tablespace space run out and ended up in an application failure.  I have questioned my DBA and he just plainly blamed the application team members who loaded large number records without a prior notice.  A convincing answer, but you can’t really fool Oracle.

Oracle introduced a new DBA_TABLESPACE_USAGE_METRICS view from 10g onwards to report the space usage with in a tablespace.  I created a new tablespace and immediately (more...)