|
Volkswagen has released some information about their 1 liter per 100km car that will supposedly debut in 2010 , and I have to say it looks cool: It provides the combination of compactness and fuel economy that usually only motorcycles reach, and at the same time protects from the elements . As I've always loved the old Messerschmitt mini-cars it resembles I may be strongly tempted when it comes out. At one liter, the mil..
|
|
I’ve talked about web 2.0, talked about web 3.0, but today realized theres still a middle ground we have to reach in between the two. It’s quite a pain that I really have no idea when my friends do certain things online. While some use facebook for absolutely everything, this is most certainly NOT the best option. Throwing your data into their walled garden is one thing, but for this to be the one and only place you store your online data i....
|
|
I’ve talked about web 2.0, talked about web 3.0, but today realized theres still a middle ground we have to reach in between the two. It’s quite a pain that I really have no idea when my friends do certain things online. While some use facebook for absolutely everything, this is most certainly NOT the best option. Throwing your data into their walled garden is one thing, but for this to be the one and only place you store your online data i....
|
|
In Let your examples flow, Dan North describes how “Don’t Repeat Yourself” (DRY) isn’t necessarily the most important guideline for tests. While I agree with his conclusions, I think the DRY principle is still extremely important for tests. Dan’s point is that the most important attribute of tests is that they can be read like a story. “Store a page with the text ‘foo’ in the database, simulate a web request, check that the word ‘foo’ is pr..
|
|
I’ve written many posts here about business, technology, and the like. The reason I’ve been so delayed in updating, in addition to the busyness of life, is because this post has been brewing in my head for quite some time. I just haven’t been able to sit down and actually compose it until now for some reason. So many of my posts have been about the web and how things will change in the future. Well while in this post it is still strongly ....
|
|
I’ve written many posts here about business, technology, and the like. The reason I’ve been so delayed in updating, in addition to the busyness of life, is because this post has been brewing in my head for quite some time. I just haven’t been able to sit down and actually compose it until now for some reason. So many of my posts have been about the web and how things will change in the future. Well while in this post it is still strongly ....
|
|
Today is Bill Gates’ last day at the helm of the largest software company in history: Microsoft. Bill, thanks for creating and running a company that has transformed the industry like no other - I wish you the best! Although I am not a huge fan of proprietary software today or some of the things that Microsoft has done (e.g. FUD) and is currently doing (e.g. Vista), I have always had a large amount of respect for Microsoft’s role in indu..
|
|
Today is Bill Gates’ last day at the helm of the largest software company in history: Microsoft. Bill, thanks for creating and running a company that has transformed the industry like no other - I wish you the best! Although I am not a huge fan of proprietary software today or some of the things that Microsoft has done (e.g. FUD) and is currently doing (e.g. Vista), I have always had a large amount of respect for Microsoft’s role in indu..
|
|
The TED conference has some amazing talks. If you never knew you were interested in car seats for children, classical music, or feet (yeah!), some of these talks will blow you mind. A recent video that really moved me was Benjamin Zander, the conductor of the Boston Philharmonic. His insights and inspiration is invaluable for everyone who considers themselves a leader. “The conductor doesn’t make a sound, he depends for his power on the abi..
|
|
At the last meeting in Oslo Lean Meetup Geoff Watts talked about BTs transition to agility. The most memorable part to me was when BT transformed a huge, waterfall type project with a delivery schedule measured in years into an agile project. The project set out to convert all BT customers to a new network with a brand new set of services. The new objective was simpler: Deliver one service to one customer in eight weeks.
|
|
Don’t swerve when people pass too close. There are many parked cars.
I sustained broken teeth and ripped muscles.
I now have this:
|
|
Don’t swerve when people pass too close. There are many parked cars.
I sustained broken teeth and ripped muscles.
I now have this:
|
|
Metric-Driven Management Versus Management-Driven Metrics
-
www.thoughtworks.com
-
18 years ago
-
eng
The demand for IT metrics is outstripping IT's ability to produce them. Part of this is due to the increase in quantitative management practices in business, the trend being to measure everything in sight in an effort to show change in performance over time as well as competitiveness (to the extent possible) relative to commercial peers. But part of this is also self-inflicted: long delivery horizons punctuated by abstract milestones make I..
|
|
People always talk about how learning is something that happens in groups. Last week, I got reminded of the point as a task I had previously struggled with alone became trivial in a pair programming episode. The first time I tried coding “a bowling scoring program” was in 2001. I’ve practices the exercise many times later. In 2004, I tried to write a more challenging version: Write a program that prints the numbers that should be displayed ..
|
|
Three years ago, I was asked by one of our teams to give advice on how they should write a parser for a structured file format. Just having read up on SAX again, I recommended that they looked into designing it as a push parser. A push parser works by the design that the parser generates events each times it reads parts of the input. These events are sent to an event handler, which then builds up the internal object structure or whatever th..
|
|
Another use case for WaitProf – diagnosing “events in waitclass Other”
-
tanelpoder.com
-
18 years ago
-
eng
I recently diagnosed a performance issue where the “events in waitclass Other” occasionally took significant part of the session’s response time. For example Snapper (which reads wait event data from V$SESSION_EVENT) reported that during measuring 39.9% of the response time was spent on “events in waitclass Other”. SQL> @sn 1 119 -- Session Snapper v1.07 by Tanel Poder ( ) ------------------------------------------------------------------....
|
|
Another use case for WaitProf – diagnosing “events in waitclass Other”
-
tanelpoder.com
-
18 years ago
-
eng
I recently diagnosed a performance issue where the “events in waitclass Other” occasionally took significant part of the session’s response time. For example Snapper (which reads wait event data from V$SESSION_EVENT) reported that during measuring 39.9% of the response time was spent on “events in waitclass Other”. SQL> @sn 1 119 -- Session Snapper v1.07 by Tanel Poder ( ) ------------------------------------------------------------------....
|
|
This week I want to talk about one of the hands-down best sites on the internet. Mint.com, in case you haven’t heard about Mint yet, it’s like Quicken or Microsoft Money just online. You create an account on the website, login, add your account information. From there mint connects to each of your accounts, pulls down your transaction history, automatically categorizes your spending into categories, and then will send you alerts for budgets....
|
|
This week I want to talk about one of the hands-down best sites on the internet. Mint.com, in case you haven’t heard about Mint yet, it’s like Quicken or Microsoft Money just online. You create an account on the website, login, add your account information. From there mint connects to each of your accounts, pulls down your transaction history, automatically categorizes your spending into categories, and then will send you alerts for budgets....
|
|
I had a following situation few days ago – I was running a CREATE TABLE AS SELECT over a heterogenous services dblink. However I cancelled this command via pressing CTRL+C twice in Windows sqlplus (this actually just kills the client sqlplus and not the call). Anyway, when I wanted to drop that table involved, this happened: SQL> drop table MYTABLE; drop table MYTABLE * ERROR at line 1: ORA-00054: resource busy and acquire with NOWAIT s....
|
|
I had a following situation few days ago – I was running a CREATE TABLE AS SELECT over a heterogenous services dblink. However I cancelled this command via pressing CTRL+C twice in Windows sqlplus (this actually just kills the client sqlplus and not the call). Anyway, when I wanted to drop that table involved, this happened: SQL> drop table MYTABLE; drop table MYTABLE * ERROR at line 1: ORA-00054: resource busy and acquire with NOWAIT s....
|
|
If you haven’t seen the Meatlink note 565424.1 in the news yet, cursor_space_for_time parameter will be deprecated in Oracle 10.2.0.5 and 11.1.0.7. That’s kind of good news, I hope this will eventually reduce the number of expert DBAs who set this parameter to true whenever they see any kind of shared pool / library cache latch contention. On the other hand, spin_count was made an undocumented parameter long time ago, but is still hea..
|
|
If you haven’t seen the Meatlink note 565424.1 in the news yet, cursor_space_for_time parameter will be deprecated in Oracle 10.2.0.5 and 11.1.0.7. That’s kind of good news, I hope this will eventually reduce the number of expert DBAs who set this parameter to true whenever they see any kind of shared pool / library cache latch contention. On the other hand, spin_count was made an undocumented parameter long time ago, but is still hea..
|
|
Warning: This article requires a lot of editing love before it is very useful. It might be somewhat incoherent. Read at your own risk. ;-) Silo (software): A silo system cannot easily integrate with any other system. In software, the term “silo” is used to refer to a system that is constructed as one unit from the front end to the data storage. Everything is tied together to work with the rest of the silo, but not with other elements.
|
|
Advanced Oracle Troubleshooting Guide, Part 6: Understanding Oracle execution plans with os_explain
-
tanelpoder.com
-
18 years ago
-
eng
Get ready for some more adventures in Oracle process stack! Before proceeding though, please read this post about safety of different stack sampling approaches. I have had few non-trivial Oracle troubleshooting cases, related to query hangs and bad performance, where I’ve wanted to know where exactly in execution plan the current execution is. Remember, Oracle is just another program executing instructions clustered in functions on ..
|
|
Advanced Oracle Troubleshooting Guide, Part 6: Understanding Oracle execution plans with os_explain
-
tanelpoder.com
-
18 years ago
-
eng
Get ready for some more adventures in Oracle process stack! Before proceeding though, please read this post about safety of different stack sampling approaches. I have had few non-trivial Oracle troubleshooting cases, related to query hangs and bad performance, where I’ve wanted to know where exactly in execution plan the current execution is. Remember, Oracle is just another program executing instructions clustered in functions on ..
|
|
Whenever I deliver training or conference presentations on advanced troubleshooting topics, I usually spend some time demonstrating how to get and interpret Oracle server process stack traces. As I’ve mentioned before, stack traces are the ultimate indicators showing where in Oracle kernel (or whatever application) code the execution currently is (or where it was when a crash occurred). This is the reason Oracle Support asks for stack tra....
|
|
Whenever I deliver training or conference presentations on advanced troubleshooting topics, I usually spend some time demonstrating how to get and interpret Oracle server process stack traces. As I’ve mentioned before, stack traces are the ultimate indicators showing where in Oracle kernel (or whatever application) code the execution currently is (or where it was when a crash occurred). This is the reason Oracle Support asks for stack tra....
|
|
There’s been a lot of buzz in the valley lately around this very small startup, that has a few pretty heavy hitters. Between the four founders they have worked on nearly all of the Google products so many know and love, with the exception of search. Paul Bucheit, is even responsible for Google’s current motto, “don’t be evil”. These four guys not only are visionaries within the web space, they also know how to deliver a product, having help....
|
|
There’s been a lot of buzz in the valley lately around this very small startup, that has a few pretty heavy hitters. Between the four founders they have worked on nearly all of the Google products so many know and love, with the exception of search. Paul Bucheit, is even responsible for Google’s current motto, “don’t be evil”. These four guys not only are visionaries within the web space, they also know how to deliver a product, having help....
|
|
If you’re writing software using a database system such as MySQL, your code doesn’t have access to all the data at any point in time, you SELECT just the data you need to operate on. If you want to do some database-wide operation, you need to ask the database to do it, because you don’t have all the rows. When you want to enforce uniqueness, for example across a whole table (for example a document name needs to be unique), or across a p..
|
|
WebTek: Unique constraints and the `alreadyexists` error
-
www.databasesandlife.com
-
18 years ago
-
eng
The only way to enforce unique constraints on a database table is by asking the database to do it . Create the table, create the unique constraint, do an insert, and parse the error message if the insert failed, to see if it was a unique constraint violation. Any kind of SELECT COUNT(*) before an insert will not work. This is now available automatically from WebTek. If the underlying table has any unique constraints, if they are violat..
|
|
I received a question on what’s the point of the use of Mutexes for Oracle cursors in library cache. For short intro, I’m pasting one of my fairly recent answers in Oracle forums about Oracle mutexes here: In Oracle, latches and mutexes are different things and managed using different modules. KSL* modules for latches and KGX* for mutexes. General mutex operatins require less CPU instructions than latch operations (as they aren’t as sop..
|
|
I received a question on what’s the point of the use of Mutexes for Oracle cursors in library cache. For short intro, I’m pasting one of my fairly recent answers in Oracle forums about Oracle mutexes here: In Oracle, latches and mutexes are different things and managed using different modules. KSL* modules for latches and KGX* for mutexes. General mutex operatins require less CPU instructions than latch operations (as they aren’t as sop..
|
|
Oracle has an unusual feature, which attracts it a lot of criticism. If you try to insert the empty string into a column marked "not null", you get an error. The empty string is treated the same as "null" by Oracle. This is different to programming languages (and indeed other databases, at least MySQL), which means one has to be careful not to make a mistake when using a programming language to talk to the database. That it’s different fr..
|
|
So this week they announced what many expected was coming the iPhone 3g. However off the shelf it’s still not web 2.0, while a great device its not a web 2.0 device yet. Apple without a doubt understands user experience, but they do not fully grasp web 2.0 yet. Microsoft seems to even have a better understanding with the products they are looking to role out with Mesh and their enterprise social/collaboration tools. Lot’s of great applica....
|
|
So this week they announced what many expected was coming the iPhone 3g. However off the shelf it’s still not web 2.0, while a great device its not a web 2.0 device yet. Apple without a doubt understands user experience, but they do not fully grasp web 2.0 yet. Microsoft seems to even have a better understanding with the products they are looking to role out with Mesh and their enterprise social/collaboration tools. Lot’s of great applica....
|
|
While I may or may not know how to be successful in silicon valley, I feel pretty confident that I can point out a few ways to not be successful in valley terms. What follows is my thoughts on how you can best limit yourself to own, run, or be involved in the entrepreneurial spirit of the valley. The first is keeping yourself in a bubble, by not diving into the new technologies, new services, and new age of the web there’s little possibil....
|
|
While I may or may not know how to be successful in silicon valley, I feel pretty confident that I can point out a few ways to not be successful in valley terms. What follows is my thoughts on how you can best limit yourself to own, run, or be involved in the entrepreneurial spirit of the valley. The first is keeping yourself in a bubble, by not diving into the new technologies, new services, and new age of the web there’s little possibil....
|
|
Over the years we at Nemein have been experimenting with various ways of keeping our operations managed. Now with some personnel changes including Joe's departure it was a good time to change the way we work again. I had some goals: Keeping status of different projects up-to-date with more accuracy Ensuring our sales and project management knows if some project is being blocked by missing materials Enabling a more distributed, we....
|
|
Over the years we at Nemein have been experimenting with various ways of keeping our operations managed. Now with some personnel changes including Joe's departure it was a good time to change the way we work again. I had some goals: Keeping status of different projects up-to-date with more accuracy Ensuring our sales and project management knows if some project is being blocked by missing materials Enabling a more distributed, we....
|
|
There was a recent post over at ReadWriteWeb about how content is becoming a commodity. I don’t believe many people would argue with this. While at first this wasn’t something I viewed in a positive light the more I think over it the more I see some value in it. As content does become more and more of a commodity the value in who is publishing or producing that content goes up. Five years ago if someone would have talked about some trade-se....
|
|
There was a recent post over at ReadWriteWeb about how content is becoming a commodity. I don’t believe many people would argue with this. While at first this wasn’t something I viewed in a positive light the more I think over it the more I see some value in it. As content does become more and more of a commodity the value in who is publishing or producing that content goes up. Five years ago if someone would have talked about some trade-se....
|
|
Every now and then I need to generate a large number of rows into some table. Not that I have any personal urge to do so, but you know, this is needed for some test cases and so on ;-) It’s quite well known that it’s possible to generate lots of rows using CONNECT BY LEVEL <= #rows syntax. However as the CONNECT BY LEVEL syntax is recursive by nature, it will consume more memory the more rows you query in one shot ( I think it was Mar..
|