I’ve been editing a task description in our worklog:
WL#946 TIME/TIMESTAMP/DATETIME with fractional seconds.

This has been around for a long time, and will be around for a long time. But I did think it’s at least time that we should let people know that we think about it. The specific impetus today was a fairly thorough survey of the feature request’s history in a MySQL DBA’s blog posting Once upon a timestamp(milliseconds)….

In my 2008-05-04 blog posting about the roadmap, I included WL#946 in a list with the heading “Let’s not forget that these will fit in somewhere in the 6.x / 7.x period”. There’s a lot to do — I know that’s not clear …

Very often we get the requests from customer to restore a "tiny" table from the nightly backup into the development/staging environment. This request need to be done on urgent basis as its just a matter of a one table and customer don't want to restore entire database of 10GB so the restoration might take less than 5 min - this is how most of the customer/managers thinks and they are abs right as why should it take more time for a single table?. This can be addressed by playing with the privileges and with the help of parameters available to 'mysql' command line utility

Steps to restore single table from dump file

# Create a user & GRANT him all rights on the table which need to be restored
# Start importing as show below

mysql -uRestUser -pSecret --force --one-database DB_NAME < /path/to/dumpfile.sql

ResetUser - "user" created for restoring single table

…

Monty Widenius dissects MySQL’s dual license. Intuit moves to the EPL. And more.

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“Tracking the open source news wires, so you don’t have to.”

# Monty Widenius blogged about the apparent changes to the dual licensing of MySQL.

# Intuit announced that its code.intuit.com will be moving from CPL to EPL.

# Matt Asay asked whether Google’s open source advocacy might be a scheme to lower the value of patents.

# Vision Mobile’s Andreas Constantinou explained the differences between open source …

A while ago I wrote about a tool to help make upgrades safer. Since then, we have gotten several people to help sponsor development on this tool, and a few of our customers are using it to help find problems before they upgrade their systems.

I can’t think of a single one of the Maatkit tools that didn’t grow out of the need for deeper insight into some part of the system. This tool is no exception. And as always, these tools are like flashlights. When you crouch down near the floor, and shine your flashlight under the refrigerator, you should expect to find a few things that make you cringe.

The other day, one of our customers was using this tool and we started getting an error. The error was caused by the part of the tool that verifies that result sets are the same. Our thought on how to do this was to checksum the results of a query. You can …

On our road to a MySQL Proxy GA release, there are quite a few things that need attention, one of them being multithreading.

We are actively working on release 0.8, which brings the first stage of multithreading to the table: Enabling worker threads to handle network events in parallel. The code has been available for quite some time now and we’ve started to implement several performance benchmarks to track our progress, catch regressions and deficiencies early on.

Benchmarking is an interesting field, especially since you can screw up so easily :)

To avoid making mistakes and to spend less time reinventing the wheel, we are doing the same as we are doing with the code: …

1. Defragging the Stimulus -- each [recovery] site has its own silo of data, and no site is complete. What we need is a unified point of access to all sources of information: firsthand reports from Recovery.gov and state portals, commentary from StimulusWatch and MetaCarta, and more. Suggests that Recovery.gov should be the hub for this presently-decentralised pile of recovery data.
2. Memetracker -- site accompanying the research written up by the New York Times as Researchers at Cornell, using powerful computers and clever algorithms, studied the news cycle by looking for repeated phrases and tracking their appearances on 1.6 million …

During preparation of Percona-XtraDB template to run in RightScale environment, I noticed that IO performance on EBS volume in EC2 cloud is not quite perfect. So I have spent some time benchmarking volumes. Interesting part with EBS volumes is that you see it as device in your OS, so you can easily make software RAID from several volumes.

So I created 4 volumes ( I used m.large instance), and made:

RAID0 on 2 volumes as:
mdadm -C /dev/md0 --chunk=256 -n 2 -l 0 /dev/sdj /dev/sdk


RAID0 on 4 volumes as:
mdadm -C /dev/md0 --chunk=256 -n 4 -l 0 /dev/sdj /dev/sdk /dev/sdl /dev/sdm

RAID5 on 3 volumes as:
mdadm -C /dev/md0 --chunk=256 -n 3 -l 5 /dev/sdj /dev/sdk /dev/sdl


RAID10 on 4 volumes in two steps:

mdadm -v --create /dev/md0 --chunk=256 --level=raid1 --raid-devices=2 …

On our road to a MySQL Proxy GA release, there are quite a few things that need attention, one of them being multithreading.

We are actively working on release 0.8, which brings the first stage of multithreading to the table: Enabling worker threads to handle network events in parallel. The code has been available for quite some time now and we’ve started to implement several performance benchmarks to track our progress, catch regressions and deficiencies early on.

Benchmarking is an interesting field, especially since you can screw up so easily :)

To avoid making mistakes and to spend less time reinventing the wheel, we are doing the same as we are doing with the code: …

On our road to a MySQL Proxy GA release, there are quite a few things that need attention, one of them being multithreading.

We are actively working on release 0.8, which brings the first stage of multithreading to the table: Enabling worker threads to handle network events in parallel. The code has been available for quite some time now and we’ve started to implement several performance benchmarks to track our progress, catch regressions and deficiencies early on.

Benchmarking is an interesting field, especially since you can screw up so easily :)

To avoid making mistakes and to spend less time reinventing the wheel, we are doing the same as we are doing with the code: …

Only the other day I was talking with someone who does a lot of work on the shell command line, but hadn’t used the GNU screen tool, so I’d better scribble a post about it as I regard it as an absolute must-have for any remote work, for multiple reasons.

First of all, what screen does. You start screen inside a terminal session (local or SSH remote), and then you can create additional sessions though Ctrl-A C. The initial screen is number 0, the next one 1, and so on. You can switch between screens with Ctrl-A # where # is the screen number. This way, you can have multiple things going within a single ssh connection, very handy. But that’s not all!

If you get disconnected (it happens and you reconnect, your screen sessions will still be there, and running too. You can reattach with screen -r. To do a nice disconnect, you can do Ctrl-A D (detach) before …