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The following cycle never ceases to amaze me: People learning programming find “real” languages such as C++ or Java filled with too many “complex” constructs. They find or invent languages such as Javascript or PHP or BASIC and think they can get the job done without “unnecessary complexity” As these programmers develop, they develop increasing complex programs, and find that constructs such as classes, inheritance, exceptions, generics/t....
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Oracle has evolved over time to much more than just a plain relational database. One option is to use Oracle as an expensive calculator. When researching or demoing Oracle, it’s quite convenient to do number calculations directly on sqlplus prompt, especially if dealing with internals where lots of stuff is about addresses and offsets shown in hex. Here’s the script what I use for such purposes: https://github.com/tanelpoder/tpt-oracl..
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Oracle has evolved over time to much more than just a plain relational database. One option is to use Oracle as an expensive calculator. When researching or demoing Oracle, it’s quite convenient to do number calculations directly on sqlplus prompt, especially if dealing with internals where lots of stuff is about addresses and offsets shown in hex. Here’s the script what I use for such purposes: https://github.com/tanelpoder/tpt-oracl..
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I shall be blogging here henceforth. I have moved all my old articles over from my previous uboot.com blog. The reason for the move was multiple: It's important to use the software you write, to experience its successes and limitations. I am a contractor for uboot and have been using their blog; however I am also a contractor for easyname and in December we took the hosting features online we'd been developing in 2006. I'm glad to....
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Why does Oracle parameter count change during session lifetime?
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tanelpoder.com
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18 years ago
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eng
I was once asked a question, why does Oracle change its parameter count during session lifetime? The question arose from the following observation that v$parameter shows more parameters after you adjust some hidden parameter value: SQL> SQL> select count(*) from v$parameter; COUNT(*) ---------- 288 SQL> SQL> alter session set "_complex_view_merging"=false; Session altered. SQL> select count(*) from v$parameter; COUNT(*) ---------- ....
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Why does Oracle parameter count change during session lifetime?
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tanelpoder.com
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18 years ago
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eng
I was once asked a question, why does Oracle change its parameter count during session lifetime? The question arose from the following observation that v$parameter shows more parameters after you adjust some hidden parameter value: SQL> SQL> select count(*) from v$parameter; COUNT(*) ---------- 288 SQL> SQL> alter session set "_complex_view_merging"=false; Session altered. SQL> select count(*) from v$parameter; COUNT(*) ---------- ....
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How many times have you seen a following case, where a user or developer complains that their Oracle session is stuck or running very slowly and the person who starts investigating the issue does following: Checks the database for locks Checks free disk space Checks alert log Goes back to the client saying “we did a healthcheck and everything looks ok” and closes the case or asks the user/developer to contact application support team or t....
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How many times have you seen a following case, where a user or developer complains that their Oracle session is stuck or running very slowly and the person who starts investigating the issue does following: Checks the database for locks Checks free disk space Checks alert log Goes back to the client saying “we did a healthcheck and everything looks ok” and closes the case or asks the user/developer to contact application support team or t....
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When I read my Google news today and found out that AOL is no longer going to develop and support Netscape as of February 2008, the first thing that came to mind was: What the heck? I thought Netscape was already dead! I always equated Netscape with older systems such as Windows 9x and SCO Unixware 7.1.2 (the only web browser that ran on its crappy GUI). I haven’t heard anyone who has used the browser in years. Everyone I know uses I..
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When I read my Google news today and found out that AOL is no longer going to develop and support Netscape as of February 2008, the first thing that came to mind was: What the heck? I thought Netscape was already dead! I always equated Netscape with older systems such as Windows 9x and SCO Unixware 7.1.2 (the only web browser that ran on its crappy GUI). I haven’t heard anyone who has used the browser in years. Everyone I know uses I..
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It is now more than 30 years since the first real game console (the Atari 2600) was released in Canada. Below is a timeline of each major console, the CPU/GPU they used and any other neat stuff. Basically, you will notice two important trends: The console manufacturers love to copy each other - up to the mid-1980s, they mostly had MOS 6502-based CPUs - in the late 1980s and early 1990s, they had Motorola 68000-based CPUs - in the mid-1..
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It is now more than 30 years since the first real game console (the Atari 2600) was released in Canada. Below is a timeline of each major console, the CPU/GPU they used and any other neat stuff. Basically, you will notice two important trends: The console manufacturers love to copy each other - up to the mid-1980s, they mostly had MOS 6502-based CPUs - in the late 1980s and early 1990s, they had Motorola 68000-based CPUs - in the mid-1..
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I’ve had a new iPhone for about a week now, so I figure it’s time to write up some thoughts about it. First, the little things. It is, in typical Apple fashion, an incredibly slick piece of work. Scrolling and zooming images or webpages is simple, easy, and, well, just fun to do and watch. Mobile Safari does a great job of making full webpages usable on the tiny screen.
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I’ve had a new iPhone for about a week now, so I figure it’s time to write up some thoughts about it. First, the little things. It is, in typical Apple fashion, an incredibly slick piece of work. Scrolling and zooming images or webpages is simple, easy, and, well, just fun to do and watch. Mobile Safari does a great job of making full webpages usable on the tiny screen.
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It has truly been an exciting year, and I wish to take a few moments to reflect on some of the most important events of 2007 in geekdom: Halo 3 being released (I love that game) Microsoft pissing off millions with Vista The death of SCO (may they rot in hell) Apple releasing the iPhone and iPod touch (the next generation interface for everything) The introduction of the Nokia N810 Internet Tablet running Linux (drool….)
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It has truly been an exciting year, and I wish to take a few moments to reflect on some of the most important events of 2007 in geekdom: Halo 3 being released (I love that game) Microsoft pissing off millions with Vista The death of SCO (may they rot in hell) Apple releasing the iPhone and iPod touch (the next generation interface for everything) The introduction of the Nokia N810 Internet Tablet running Linux (drool….)
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Wolfgang Breitling has written a snapper.pl script – Perl version of my original snapper.sql one. Check it out! As his script doesn’t rely on DBMS_OUTPUT for generating output, you can easily get real time continuous output with his script, without needing to wait until the script finishes or by using somewhat complicated DBMS_SYSTEM.KSDWRT tracefile output. Also, as his script doesn’t rely on DBMS_LOCK package for sleeping, so you..
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Wolfgang Breitling has written a snapper.pl script – Perl version of my original snapper.sql one. Check it out! As his script doesn’t rely on DBMS_OUTPUT for generating output, you can easily get real time continuous output with his script, without needing to wait until the script finishes or by using somewhat complicated DBMS_SYSTEM.KSDWRT tracefile output. Also, as his script doesn’t rely on DBMS_LOCK package for sleeping, so you..
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Sqlplus is my second home, part 5: Reading the name of currently executing script
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tanelpoder.com
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18 years ago
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eng
If you need to run and manage loads of sqlplus scripts which call other scripts, which call other scripts etc, then you are probably interested in the sqlplus APPINFO parameter shown below. When you issue SET APPINFO ON in sqlplus, this makes sqlplus to automatically call DBMS_APPLICATION_INFO.SET_MODULE and set the MODULE value to sql script name which is currently being executed. This allows you to easily pass the current script nam....
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Sqlplus is my second home, part 5: Reading the name of currently executing script
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tanelpoder.com
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18 years ago
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eng
If you need to run and manage loads of sqlplus scripts which call other scripts, which call other scripts etc, then you are probably interested in the sqlplus APPINFO parameter shown below. When you issue SET APPINFO ON in sqlplus, this makes sqlplus to automatically call DBMS_APPLICATION_INFO.SET_MODULE and set the MODULE value to sql script name which is currently being executed. This allows you to easily pass the current script nam....
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Installing this into Firefox (takes < 1 minute and doesn’t require a download) allows you to check for the availability of domain names straight from the browser. It was created by my colleague, who works with me at easyname.eu, but it was his idea, and I genuinely think it’s a cool feature!
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If one defines a class with the member variable: protected static $bytes = 12582912; then that’s fine. However if one defines it as: protected static $bytes = 12*1024*1024; // 12 MB then that gives a compile error: Parse error: syntax error, unexpected '*', expecting ',' or ';' I know of no other language that I’ve ever programmed (i.e. including BASIC, and C) where you can write a value, but you can’t write an expression.
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Last time I tried to run Asterisk on OS X it was on Panther (10.3), and it really failed to work. It seems since I last looked, things have come a long way. When rearranging how my personal VoIP was configured, I was looking for a simple SIP proxy - however, the only one I could find immediately was Java based, and lacking on a few features that I wanted. Hence, I decided to check out if there were any better Asterisk packages available. I ..
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Last time I tried to run Asterisk on OS X it was on Panther (10.3), and it really failed to work. It seems since I last looked, things have come a long way. When rearranging how my personal VoIP was configured, I was looking for a simple SIP proxy - however, the only one I could find immediately was Java based, and lacking on a few features that I wanted. Hence, I decided to check out if there were any better Asterisk packages available. I ..
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Dominos 2: Winter Edition is a physics based platformer where you play as a little green alien who can roll around and stick to things. In story mode, after your space ship crash lands on earth, navigate the snowy landscape to try and find your way back home, by surfing on dominos, carefully crawling along ceilings, sledding over spikes, and solving fun puzzles. Beyond story mode, there is a powerful level editor which gives you the full..
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Dominos 2: Winter Edition is a physics based platformer where you play as a little green alien who can roll around and stick to things. In story mode, after your space ship crash lands on earth, navigate the snowy landscape to try and find your way back home, by surfing on dominos, carefully crawling along ceilings, sledding over spikes, and solving fun puzzles. Beyond story mode, there is a powerful level editor which gives you the full..
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It seems that with the rising oil prices the Age of Sail is returning, even if in a modified format. SkySails is a system that enables freighters to tap into high-altitude winds with a power kite to reduce fuel consumption. Watch the video presentation for more information. Everything old is new again! Via Slashdot . In sailing-related news , I posted some photos of the 2001 Heimlösa Rus reconstructed viking ship tri..
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It seems that with the rising oil prices the Age of Sail is returning, even if in a modified format. SkySails is a system that enables freighters to tap into high-altitude winds with a power kite to reduce fuel consumption. Watch the video presentation for more information. Everything old is new again! Via Slashdot . In sailing-related news , I posted some photos of the 2001 Heimlösa Rus reconstructed viking ship tri..
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I finally got myself an iPhone - and am loving it. It’s great how I can now sync my calendars, and address book to my phone without having to worry at all about having six clones of each event on my calendar (which of course, makes it rather difficult to tell what I’m actually meant to be doing that day). However, a topic that has come up a couple of times in discussion with a few friends is that of the iPhone SDK. I feel that the big quest....
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I finally got myself an iPhone - and am loving it. It’s great how I can now sync my calendars, and address book to my phone without having to worry at all about having six clones of each event on my calendar (which of course, makes it rather difficult to tell what I’m actually meant to be doing that day). However, a topic that has come up a couple of times in discussion with a few friends is that of the iPhone SDK. I feel that the big quest....
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Further to the previous comment, you can also link against GSL from within an Xcode project: Create an Xcode "C++ Tool" project from the command line projects options. Within the project Ctrl+Click on the project name, and select "Get Info" Use the Spotlight-esque search at the top of this window to search for Compiler, and select the "Other C++ Flags" text box. Into the box enter -I/opt/local/include -L/opt/local/lib ..
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Further to the previous comment, you can also link against GSL from within an Xcode project: Create an Xcode "C++ Tool" project from the command line projects options. Within the project Ctrl+Click on the project name, and select "Get Info" Use the Spotlight-esque search at the top of this window to search for Compiler, and select the "Other C++ Flags" text box. Into the box enter -I/opt/local/include -L/opt/local/lib ..
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There has been a lot of hype this week about Kindle - Amazon’s eBook reader. I have always regarded eBooks (also referred to as Digital Ink) as evil. They are almost always DRM (Digital Rights Management) protected so that you can’t share information with others and typically require an expensive eBook reader. On the other side, the idea of storing my book collection on a nice small aesthetic digital device seems attractive to me as a ..
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I’ve taken a look at the state of vector graphics in the browser. Since the beginning of the web, people have been using GIFs to display their headline texts; tables and CSS to do layout; and GIFs for rounded corners etc. A lot of this would become a lot simpler if the browser was able to display vector graphics. There are numerous systems for displaying vector graphics but the two I looked at in detail were the
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There has been a lot of hype this week about Kindle - Amazon’s eBook reader. I have always regarded eBooks (also referred to as Digital Ink) as evil. They are almost always DRM (Digital Rights Management) protected so that you can’t share information with others and typically require an expensive eBook reader. On the other side, the idea of storing my book collection on a nice small aesthetic digital device seems attractive to me as a ..
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A while back I was doing some performance tuning on MySQL 5 for a customer. A SELECT was counting the number of rows in the table. I always use COUNT(*) for that but I know a lot of people, including the customer, use COUNT(pk_col). The query was taking a long time (a few minutes). I analyzed that the problem came from the usage of COUNT(pk_col) instead of COUNT(*). With COUNT(*) it was instantaneous.
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Oracle Security, Part 2: Your read only accounts aren’t that read only
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tanelpoder.com
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18 years ago
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eng
Couple of years ago an interesting fact floated up in Oracle-L – a regular user with only SELECT privilege on a table can successfully execute a SELECT FOR UPDATE against it, locking all rows and even lock the whole table using LOCK TABLE command. Locking a table in exclusive mode would stall all changes and selects against that table – effectively hanging all applications using that table. Pete Finnigan wrote a review of the issue in this..
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Oracle Security, Part 2: Your read only accounts aren’t that read only
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tanelpoder.com
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18 years ago
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eng
Couple of years ago an interesting fact floated up in Oracle-L – a regular user with only SELECT privilege on a table can successfully execute a SELECT FOR UPDATE against it, locking all rows and even lock the whole table using LOCK TABLE command. Locking a table in exclusive mode would stall all changes and selects against that table – effectively hanging all applications using that table. Pete Finnigan wrote a review of the issue in this..
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Since I’m taking the Computational Physics module in my third year at IC, we’re using some libraries like GSL to provide “better-than-default” random number generators and such like. It turns out that those of us using a Mac don’t get GSL installed by default with Xcode, or under OS X - and unlike Windows and Linux - there’s no instructions on the course site. Here’s a really quick way to ensure that you can link against it:
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Since I’m taking the Computational Physics module in my third year at IC, we’re using some libraries like GSL to provide “better-than-default” random number generators and such like. It turns out that those of us using a Mac don’t get GSL installed by default with Xcode, or under OS X - and unlike Windows and Linux - there’s no instructions on the course site. Here’s a really quick way to ensure that you can link against it:
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Do you remember the dawn of the Internet in the mid 1990s? Everyone was talking about the “Information Superhighway” (a cheesy term for the Internet back then) and how it would change everyone’s life. Then people starting talking about the World Wide Web (WWW) and email and facebook. Still today, many people don’t know how to properly define the World Wide Web and the Internet. At dinner parties with non-geek friends, I like to bring t..
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Do you remember the dawn of the Internet in the mid 1990s? Everyone was talking about the “Information Superhighway” (a cheesy term for the Internet back then) and how it would change everyone’s life. Then people starting talking about the World Wide Web (WWW) and email and facebook. Still today, many people don’t know how to properly define the World Wide Web and the Internet. At dinner parties with non-geek friends, I like to bring t..
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