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:
This article is written with examples taken from an (virtualised) Oracle Linux 6u6 X86_64 operating system, and Oracle database version 220.127.116.11.1. 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...)
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
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...)
Since some time I have been adding
WHERE 1=1 to all my queries.
I get queries like this:
FROM emp e
AND e.ename LIKE 'A%'
AND e.deptno = 20
Lots of people ask me what’s the use of this
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...)
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
, dt2 "date"
, cast(dt2 as timestamp) "timestamp"
, to_Char(cast(dt2 as timestamp),'DD-MON-YYYY (more...)
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 18.104.22.168 DB for a check-test and it was empty! My (more...)
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...)
In an earlier post, I mentioned that Oracle has finally, offcially supported the Oracle Management Repository (OMR) on Database 12c (22.214.171.124). 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...)
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 […]
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...)
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...)
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.
Here’s a summary of what the (more...)
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 […]
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...)
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 […]
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...)