As you may know, InnoDB has 2 limits for unflushed modified blocks in the buffer pool. The one is from physical size of the buffer pool. And the another one is oldness of the block which is from the capacity of transaction log files.

In the case of heavy updating workload, the modified ages of the many blocks are clustered. And to reduce the maximum of the modified ages InnoDB needs to flush many of the blocks in a short time, if these are not flushed at all. Then the flushing storm affect the performance seriously.

We suggested the "adaptive_checkpoint" option of constant flushing to avoid such a flushing storm. And finally, the newest InnoDB Plugin 1.0.4 has the new similar option "adaptive_flushing" as native.

Let's check the adaptive flushing options at this post.

HOW THEY WORK

< adaptive_checkpoint=reflex (older method)>

gromit is my Solaris 10 server, chorlton is my OSX desktop. Explain this:

root@gromit# zfs set sharenfs='anon=shared,sec=none' gromit/store

root@gromit# zfs get sharenfs gromit/store
NAME          PROPERTY  VALUE                 SOURCE
gromit/store  sharenfs  anon=shared,sec=none  local

user@chorlton$ ls /net/gromit/store
ls: cannot open directory /net/gromit/store/: Operation not permitted

root@gromit# zfs set sharenfs='anon=shared' gromit/store

user@chorlton$ ls /net/gromit/store
file1  file2

user@chorlton$ touch /net/gromit/store/file3
touch: /net/gromit/store/file3: Permission denied

root@gromit# zfs set sharenfs='anon=shared,sec=none' gromit/store

user@chorlton$ touch /net/gromit/store/file3
user@chorlton$ echo $?
0

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There will be plenty of detailed coverage on Exadata V2 so I won’t attempt to replicate that.  However I do have a couple of initial thoughts which I would like to share.  For those who missed it, Oracle has just announced Exadata V2 (which is their pre-built “machine”).  Exadata V1 was built using HP equipment, Exadata V2 is using Sun.  The main addition to Exadata V2 seems to be an extra tier in the memory hierarchy, a flash cache.  Oracle is very quick to point out this is not flash disk, but it is flash memory, Sun’s FlashFire technology (flash disk or SSD’s was always going to be a transition technology, flash memory doesn’t have the …

So it turns out that a VPS server, while inexpensive, is a poor choice for a demo server of a product. So the Kontrollbase demo is now hosted on a Sun X4100 quad-opteron with 8G ram and some nice SAS disks. The new demo site is http://demo02.kontrollbase.com , the old one is located here if [...]

I have added a new Launchpad tree for an improved
partitioning feature.

This new tree is based off mysql-trunk which is the base for
the next generation MySQL Server. The tree is now entering QA
and have been extensively tested by development and thus it is
very interesting to get feedback on usability of feature and
feedback on quality issues. This will speed up the delivery of
this new feature.

You can find more description of the feature in a previous blog:
Description of feature

You are an Independent Software Vendor, and you want to develop, port, or test your application on Solaris or OpenSolaris? Sun's online Virtual Lab environment - EZQual - makes it easy for you, and it's free!

The Lab features pre-installed SPARC or x86 processor-based Sun servers with development tools (SunStudio and Netbeans), Java, AMP, memcached, Squid, Httplight, PostgreSQL, Solaris or OpenSolaris, and more.

In addition, thanks to the Sun's Secure Global Desktop, accessing this secure development environment over the Internet is just like running Solaris on your own laptop:

Want to know more? Check out the EZQual web page.

We often need many tabs open in a browser, and horizontal tabs become unmanageable. Tab Kit allows you to have them vertically on the left, with various additional configuration choices.

I opted for the tree structure, so when I open a tab from another one it’ll show up as a child to the original. I can “lock” tabs so they cannot be closed by an accidental click or keypress. They get a “read” marker so if you open a few tabs and leave them till later you can still tell which ones you’ve actually already looked at. And there’s colour coding also.

In short, a great help. Just click the Tools/Add-Ons menu in Firefox and find Tab Kit in the extensions. Install, configure, and enjoy!

I just read SQL: Ranking without self join, in which Shlomi Noach shares a nice MySQL-specific trick based on user-defined variables to compute rankings.

Shlomi's trick reminds me somewhat of the trick I came across little over a year ago to caclulate percentiles. At that time, several people pointed out to me too that using user-defined variables in this way can be unreliable.The problem with user-defined variablesSo what is the problem exaclty? Well, whenever a query assigns to a variable, and that same variable is read in another part of the query, you're on thin ice. That's because the …

Hi All,

I was moving some old posts and although I've changed the date you will see a lot of them.
Sorry for flooding Planet MySQL.

Luca

Before I even start this post I am going to repeat our view that Oracle is well aware that it has little to gain from killing off MySQL and that we expect MySQL to become the scale-out database for non-transactional web applications and to compete with SQL Server in departmental deployments.

That said there has been some interesting discussion on Twitter this week in response to the European Commission’s investigation of Oracle-Sun about whether Oracle could - in theory - kill off MySQL. Here’s a Q+A explaining my view as to how Oracle could kill MySQL but probably won’t, and why MySQL AB’s choice of dual licensing and the GPL has come back to haunt Monty Widenius.

Q. Oracle can’t kill MySQL even if it wants to, because its open source. Right?

A. …