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Archive for June 11th, 2010

Zippl – a Lightweigth Presentation Tool

June 11th, 2010 by

Recently people played around a lot with a new kind of presentations. The pages in the classical presentation tool sense seem to lie around on a large canvas and while the presentation running, the focus moves over the canvas and stops by interesting points. Zooming allows to go more in detail and other cool graphics effects make it fun to watch these presentations.

This week was the fifth Hackweek at Novell where we can pick an interesting topic and work on it. I am always interested in cool applications and I wanted to investigate a bit on Qts GraphicsView anyway so I decided to go for a proof of concept implementation of a lightweight but cool presentation tool following these concepts.

The tool is called Zippl (for no specific reason). It is implemented in C++ with Qt 4.6. Via a XML file the user can specify so called spots on the Zippl-canvas. During a presentation one after the other canvas is displayed with an animated move from one to the other.

Spots can consist of text in various fonts and sizes, geometric forms and images. Colors and line widths and stuff can be specified for each item. It is amazing what can already be done with these few elements.

But decide yourself by checking the following out, its the first little presentation done with Zippl:

With Qt its again fun to work on this kind of applications and the GraphicsView framework is awesome. If you want to see code, it is in the KDE svn, module playground/office.

What do you think? Is that something to investigate more on? You can give me feedback in openFATE about it if you want and rate it.

Guest Blog: Rares Aioanei – Weekly Kernel Review (openSUSE Flavor)

June 11th, 2010 by

Guest Blog from Rares Aioanei

Welcome to another edition of openSUSE’s kernel weekly news!
This week sees the launch of 2.6.35-rc2, plus other goodies, so let’s dive into it!

-Takashi Iwai pushed sound fixes for -rc2, mainly for the USB audio stack, v4l/dvb fixes were pushed by Mauro Carvalho Chehab (-rc1), Len Brown has patches for the SFI and ACPI trees targetting -rc1 and openSUSE’s Greg Kroah-Hartman also posted multiple fixes for USB, driver-core, staging and TTY and serial targetting 2.6.35-git.

-Grant Likely has fixes for the sparc architecture : “This patch moves SPARC architecture specific data members out of struct of_device and into the pdev_archdata structure. The reason for this change is to unify the struct of_device definition amongst all the architectures.  It also remvoes the .sysdata, .slot, .portid and .clock_freq properties because they aren’t actually used by anything.

A subsequent patch will replace struct of_device entirely with struct platform_device and the of_platform support code will share common routines with the platform bus (but the bus instances themselves can remain separate).

This patch also adds ‘struct resources *resource’ and num_resources to match the fields defined in struct platform_device.  After this change, ‘struct platform_device’ can be used as a drop-in replacement for ‘struct of_platform’.

This change is in preparation for merging the of_platform_bus_type with the platform_bus_type.”

-Al Viro posted fixes for the vfs tree targetting -rc2, while Ryusuke Konishi and David Miller posted patches for the nilfs2 and networking trees, respectively. Alex Elder updated the XFS tree  for -rc2, Jens Axboe updated block for -rc1, Michal Simek updated the arch/microblaze tree with fixes targetting 2.6.35-rc3 and Jeff Garzik updated the libata tree with some quirk fixes.

-Jeffrey Merkey announced Merkey’s Kernel Debugger 2.6.34 :  “Have not tested the APIC IPI calls yet but should work.  Let me know if there are problems.  I disable the hw_breakpoints interface with MDB is loaded because it is not well designed and to be honest, virtualizing DR6 and trying to handle these types of events outside of a debugger core causes a lot of problems.  Has support for x86_64 and works under it however, I have not completed the dissassembler with the newer x86_64 instructions, so some of them do not display properly and do not detect the 64 bit flag, but will finish this at a later date as I need it.  I do most of my work on 32 bit anyway and will work on it as I have time.  Someone else is welcome to add it and send me back the changes since this is the only thing missing for full
x86_64 features — finished everything else.”

-Mr. Torvalds, Linus Torvalds, announced the release of 2.6.35-rc2 thusly :
“So -rc2 is out there, and hopefully fixes way more problems than it introduces. I’m slightly unhappy with its size – admittedly it’s not nearly as big as rc2 was the last release cycle, but that was an unusually big -rc2. And I really hoped for a calmer release cycle this time.

In fact, for once I’m going to enforce -rc3 being sane, because the  upcoming week is the last week of school for my kids. And when the kids get out of school, I’m going be offline for a while. And as a result, I _really_ don’t want to pull anything even half-way scary in the next week for -rc3.

So any pull requests had better be obvious fixes only, and this time I’m not going to let things slide.

Anyway, the biggest patches in -rc2 are some staging drivers (70% of the patch is just that), so while it’s still biggish, at least most of it is clearly staging.

Of the remaining non-staging 30%, half of _that_ is just the regular drivers (drm: i915 and radeon, along with some dvb updates is a noticeable chunk), with a new Core i7 EDAC driver that I had gotten a pull request for before -rc1, but just hadn’t had the energy to pull until -rc2 (same goes for a build system update – the pull request predated -rc1).

And some late powerpc changes that I do _not_ think predated -rc1. Tssk.  I’m really not going to let things like that slide next -rc, as mentioned.

But the most important part is obviously the regression fixes, which tend to be small and not show up much in the patch statistics. A number of reverts, a number of fixes, hopefully things are all rosy.

And it really isn’t _that_ bad – the -rc2 shortlog is almost never small  enough to be worth posting on the mailing list, but I think it’s doable this time, even if it’s borderline. So ShortLog appended if people care
about the (summary of) details.

Linus ”

-Dave Airlie updated the drm tree with some fixes as he explains in his mail : “3 regressions fixes, one radeon loading on IGP, one i865 loading, one and  an evergreen userspace interaction workaround.

It adds hwmon support for a temperature sensor on r600 cards, later PM patches were build on this and Alex had tested them in one so I didn’t want to cherry-pick around it. Also its useful to report the gpu temp to check if power management is helping cooling it down.”

-Stefan Richter came up with a single update/fix for Firewire, Martin Schwidefsky posted three bug fixes and a defconfig update for the s390 architecture targetting-rc2, Tejun Heo has also some fixes, this time for sched/core and Frederic Weisbecker updated the perf and tracing trees with various fixes.

-Karel Zak of Redhat announces util-linux-ng version 2.18-rc1, posting also the release notes, stating the updates, fixes and improvements specific to this version.

-Artem Bityutskiy posted a pull request for the UBI tree targetting -rc3, David Miller pushed another series of networking updates, Jesse Barnes updated the PCI tree, while Takashi Iwai targeted -rc3 with updates to the sound tree; other updates include perf (Ingo Molnar), perf for 2.6.36 (Arnaldo Carvalho de Melo) and block/io (Jens Axboe).

-Rafael Wysocki posted a list of reported regressions from (related to-rc2-git2), comprised of 15 regressions, from which 13 are pending and 10 are unresolved.

-Thomas Gleixner announced, a new kernel from the preempt-rt series – changelog to be found in the lkml archive.

-Avi Kivity has updates for the kvm tree targetted at -rc2, Jeff Garzik updated the libata tree with some fixes, Sage Weil, as usual, updated the ceph tree (for -rc3) and Steven Rostedt updated the perf tree (2.6.35).

That would be it for this week, take care and enjoy your weekend!

Guest Blog: Rares Aioanei – Weekly Review from PostgreSQL (openSUSE Flavor)

June 11th, 2010 by

Guest Blog from Rares Aioanei

Hello everyone and welcome to this week’s Weekly PostgreSQL News, served openSUSE-style!

-As usual, we start with some insight of this week’s mailing list events, then we will focus on the Planet PostgreSQL posts and news.

-Jon Schewe posted on perform@ an interesting comparison of various filesystems under Linux (OpenSUSE64) , how do they perform and under what circumstances. I ain’t gonna spoil
it for you, so go grab a read.

-Peter Eisentraut, on hackers@, posted a quite interesting idea titled Functional dependencies and GROUP BY : “I have developed a patch that partially implements the “functional dependency” feature that allows some columns to be omitted from the GROUP BY clause if it can be shown that the columns are functionally dependent on the columns in the group by clause and therefore guaranteed to be unique per group.  The full functional dependency deduction rules are pretty big and arcane, so I concentrated on getting a useful subset working.  In particular:

* When grouping by primary key, the other columns can be omitted, e.g.,

* CREATE TABLE tab1 (a int PRIMARY KEY, b int);

* SELECT a, b FROM tab1 GROUP BY a;

This is frequently requested by MySQL converts (and possibly others).

Also, when a column is compared with a constant, it can appear ungrouped:

SELECT x, y FROM tab2 WHERE y = 5 GROUP BY x;

For lack of a better idea, I have made it so that merge-joinable operators qualify as equality operators.  Better ideas welcome.

Other rules could be added over time (but I’m current not planning to work on that myself).

At this point, this patch could use some review and testing with unusual queries that break my implementation. 😉 ”

-This week, The San Francisco Bay Area PostgreSQL Meetup Group will have a meeting on June the 15th; here are the details : http://postgresql.meetup.com/1/calendar/13675701/

-In Planet-related news, Leo Hsu and Regina Obe write about what’s new in PostgreSQL 9.0, since the 2nd beta was released this week :  “PostgreSQL 9.0 beta 2 just got released this week. We may see another beta before 9.0 is finally released, but it looks like PostgreSQL 9.0 will be here probably sometime this month. Robert Treat has a great slide presentation showcasing all the new features. The slide share for those on Robert Treat’s slide share page.  We’ll list the key ones with our favorites at the top:
Our favorites
The window function functionality has been enhanced to support ROWS PRECEDING and FOLLOWING. Recall we discussed this in Running totals and sums using PostgreSQL 8.4 a hack for getting around the lack of ROWS x PRECEDING and FOLLOWING.
No more need for that. This changes our comparison we did Window Functions Comparison Between PostgreSQL 8.4, SQL Server 2008, Oracle, IBM DB2. Now the syntax is inching even closer to Oracle’s window functionality, far superior to SQL Server 2005/2008, and about on par with IBM DB2. We’ll do updated compare late this month or early next month. Depesz has an example of this in Waiting for 9.0 – extended frames for window functions Ordered Aggregates.
This is extremely useful for spatial aggregates and ARRAY_AGG, STRING_AGG, and medians where you care about the order of the aggregation. Will have to give it a try. For example if you are building a linestring using ST_MakeLine, a hack you normally do would be to order your dataset a certain way and then run ST_MakeLine. This will allow you to do ST_MakeLine(pt_geom ORDER BY track_time) or ARRAY_AGG(student ORDER BY score) This is very very cool. Depesz has some examples of ordered aggregates. Join removal — this is a feature that will remove joins from the execution plans where they are not needed. For example
* where you have a left join that doesn’t appear in a where or as a column in select. This is important for people like us that rely on views to allow less skilled users to be able to write meaningful queries without knowing too much about
* joins or creating ad-hoc query tools that allow users to pick from multiple tables. Check out Robert Haas why join removal is cool for more use cases. GRANT/REVOKE ON ALL object IN SCHEMA and ALTER DEFAULT PRIVILEGES. This is just a much simpler user-friendly way of applying permissions. I can’t tell you how many times we get beat up by MySQL users who find the PostgreSQL security management tricky and tedious to get right. Of course you can count on Depesz to have an example of this too Waiting  for 9.0 – GRANT ALL”

-From the PostgreSQL Weekly News from the 6th of June we find out some local news, such as the Italian Conference for Free Software (Cagliari, Sardinia) and the talks, sessions and workshops related to our fav database, we also find news about the release of ChronicDB v2.2.2, plus the usual patchlist.

There you go, that’s all for this week. Enjoy. 🙂