In this video blog, Fishbowl Solutions’ Technical Project Manager, Justin Ames, and Marketing Team Lead, Jason Lamon, discuss Fishbowl’s Agile (like) approach to managing Oracle WebCenter portal projects. Justin shares an overview of what Agile and Scrum mean, how it is applied to portal development, and the customer benefits of applying Agile to an overall portal project.
“This is my first large project being managed with an Agile-like approach, and it has made (more...)
Before LATERAL and CROSS APPLY were added (exposed to us) in 12c, a common technique to do correlated joins was using the TABLE/MULTISET technique.
For example, we might have had a couple of tables:
SQL> create table t as
2 select object_type, min(created) min_dte, max(created) max_dte
3 from dba_objects
4 where owner = 'SCOTT'
5 group by object_type;
SQL> select * from t;
OBJECT_TYPE MIN_DTE MAX_DTE
------------------- --------- ---------
INDEX 09-OCT-13 09-OCT-13
What is RequireJS and why is it important?
OpenWorld is just around the corner, and the Ask Tom team will be involved in a number of panels where you can chat to us, ask questions, debate topics and basically have a relaxed 45mins during all the frenzied activity that is OpenWorld. So if you’ve got any questions you would like answered “face to face”, rather than via Ask Tom, either drop them as a comment here, or feel free to post them (more...)
You would think that (with the exception of the V$ tables which are predominantly memory structures reflecting the state of various parts of the database instance) a query on a read-only standby database would have absolutely no interaction with the primary. After all, the standby database needs to be able to run independently of the primary should that primary database be down, or destroyed.
But there’s an exception to the rule. Consider the (more...)
Do you want to know how your company can survive Cyber Security threats? And what can be an approach to stay compliant? Have you ever thought about security related opportunities and business enablers? Then continue reading this blog post!
Digital Transformation takes place at an ever increasing pace and innovation by technology is going faster than most companies can handle. This also has a deep impact on Information Security. We have to deal with it (more...)
Still tweaking my Python based Oracle database performance tuning graphs.
I kind of like this new version of my “sigscpuio” graph:
The earlier version plotted IO, CPU, and Elapsed time summed over a group of force matching signatures. It showed the components of the time spent by the SQL statements represented by those signatures. But the IO and CPU lines overlapped and you really could not tell how the elapsed time related to IO and (more...)
As most of us know, with LAG and LEAD or more generally, any analytic function that may extend “past” the boundary of window it is operating on, you can get null as a result.
Here’s a trivial example
SQL> create table t as
2 select rownum x
3 from dual
4 connect by level <= 10;
SQL> select x, lag(x) over ( order by x ) as lag_Test
2 from t;
An AskTom contributor brought to my attention, that direct mode insert on index organized tables now appears possible in 12c. We can see the difference by running a simple script in both v11 and v12
SQL> select * from v$version;
Oracle Database 11g Enterprise Edition Release 18.104.22.168.0 - 64bit Production
PL/SQL Release 22.214.171.124.0 - Production
CORE 126.96.36.199.0 Production
TNS for (more...)
When a query contains a regular or inline view, there are 3 basic strategies for the optimizer to choose from:
1) merge the view (no “VIEW” operation in the plan)
2) instantiate the view as the whole and join it to the rest of the query (the plan shows a VIEW “operation”)
3) push join predicates inside the view (the plan shows “VIEW PUSHED PREDICATE”).
The last strategy in that list is similar to a (more...)
In my previous post I showed an example of how a query’s performance can be improved using the waste minimization technique. My focus was primarily on identifying and enforcing the correct plan, but I received some questions regarding the root cause of the problem: why the optimizer came up with a wrong join order? It’s a very interesting question, and it deserves a separate post so that it could be explored in detail.
Let’s take (more...)
One of the nifty things in 12c is the ability to pick up DBMS_OUTPUT output from your scheduler jobs. So if you haven’t built an extensive instrumentation or logging facility, you’ll still have some details you can pick up from the scheduler dictionary views. Let’s look at an example
SQL> create or replace
2 procedure do_stuff is
I made a new graph in my PythonDBAGraphs program. Here is an example with real data but the database name blanked out:
My graphs are all sized for 1920 x 1080 monitors so I can see all the detail in the lines using my entire screen. The idea for this graph is to show how the performance of the queries that matter to the users changes as we add more load and data to this (more...)
I was attempting to install an OEM management server on a new host in the lab using runInstaller. Of course the installer is an X-windows app so I need to configure port forwarding to get the display back to MacBook.
I added the new host and its bastion to my ~/.ssh/config file to set up port forwarding:
Host newlaboms. (more...)
In Part 1 we saw that the SQL function COLLECT with the DISTINCT option is not natively supported in PL/SQL, and saw two workarounds – using dynamic SQL and using the SET function.
In Part 2 we saw that the SET function can operate on Nested Table but not on Varray.
In this post we’ll see two more workarounds.
We can first remove the duplicates in an inline view, and then use the (more...)
A few weeks ago, I received a request to review an AWR report for a database suffering from instance-level performance issues. Here are the the key parts of that report (with some masking):
WORKLOAD REPOSITORY report for
DB Name DB Id Instance Inst Num Release RAC Host
------------ ----------- ------------ -------- ----------- --- ------------
XXXX XXXXX XXXXX 1 10.2.0.5.0 NO XXXX
Snap Id Snap Time Sessions Curs/Sess
--------- ------------------- -------- ---------
More news coming, but for now, we (family and I) are moving to Seattle! We will be giving up our gorgeous rental house in San Francisco thus it will be available to the next lucky family.
Elegant mediterranean style family home on a quiet tree lined street in a sweet residential neighborhood just minutes from downtown and the Peninsula.
Perfect location for commuting to Peninsula on 280 or downtown SF (more...)
You can specify a connection string for database targets in two ways: fill in the blanks and let OEM create the connection string (my preference) or paste a Preferred Connect String on the bottom of the page.
Our default setting in our shop is to use multi-threaded servers. On the rare occasion when we need to change if, we paste the connect string from tnsnames.ora in place and add the SERVER=DEDICATED parameter.
Some things to (more...)
In a recent release that I’ve been working on, we had to drop and recreate some of the unique/primary key constraints (due to columns being added into the constraint) on some of our tables.
Prior to working in this team, I had only ever come across explicitly creating the indexes for a table, similar to:
create table test_explicit_index (col1 number,
create unique index col1_exp_pk on test_explicit_index (col1);
We can see the (more...)
Those of you who know me will know that I’m working at Cedar and we’re moving from PeopleSoft to the Oracle Cloud. I won’t talk about the company’s journey, but more how I’ve found the transition personally.
In brief, there’s a lot to learn.
Data Model knowledge
In the PeopleSoft world, once you know the table structures you could work significantly faster. Whether you were writing an SQR, an App Engine, an XMLP report, a (more...)