On the way to the airport from Santa Clara (after the MySQL Users Conference) I pulled off Route 101 to grab a few snacks for the plane ride (yea, I don't like paying $4 for a warm soda at the airport). I laughed out loud when the random exit I chose just happened to be the exit for the Oracle Corporate Headquarters (another view). Really, I had no idea. I've seen them before but it was purely random (or subconscious). If you haven't been near them, the series of pods and surrounding campus is pretty cool.

I couldn't shake the irony that after having been immersed in …

At the 2004 Foo Camp, Danese Cooper, a few other FLOSS advocates (forgive me, Foo Camp is a blur and I don’t remember who you were) and myself gave an ad hoc session on the methods and strategies that we each used to advocate FLOSS and to help people working closed environments become more open.

The session was a blast (and well-received), so much so that Danese and I proposed the session for last year’s OSCON. We didn’t make the cut, but I still tried again for this year’s EuroOSCON and, this time, the session was accepted.

The session should be fun to present, but a bit of a bear to write. I have only 45 minutes to try to fit in the most …

One image I shot on the last day, which is quite perfect:

(Click on the link for a larger image)

"Hot Backups" of your MySQL Database on Linux

Would you like to take consistent snapshot backups of your entire database without a SAN or external software, and without slowing or locking your database for the duration?

RedHat? Enterprise Linux (and Centos Linux) install an LVM by default.
LVM, Logical Volume Manager is a layer that sits on top of any file system (default ext3).

You can tell if you're already running on an LVM, by checking your file system with "df -h" — an entry like "/dev/mapper/VolGroup01-LogVol00" shows that your disk is mapped through the LVM.

LVM brings you features such as the ability to grow and shrink volumes, add hard disks without migrating data, RAID0, and for the purpose of this article: file system SNAPSHOTS.

FLUSH TABLES WITH READ LOCK;
\! lvcreate --size 100m --snapshot --name snap …

"Hot Backups" of your MySQL Database on Linux

Would you like to take consistent snapshot backups of your entire database without a SAN or external software, and without slowing or locking your database for the duration?

RedHat? Enterprise Linux (and Centos Linux) install an LVM by default.
LVM, Logical Volume Manager is a layer that sits on top of any file system (default ext3).

You can tell if you're already running on an LVM, by checking your file system with "df -h" — an entry like "/dev/mapper/VolGroup01-LogVol00" shows that your disk is mapped through the LVM.

LVM brings you features such as the ability to grow and shrink volumes, add hard disks without migrating data, RAID0, and for the purpose of this article: file system SNAPSHOTS.

FLUSH TABLES WITH READ LOCK;
\! lvcreate --size 100m --snapshot --name snap …

"Hot Backups" of your MySQL Database on Linux

Would you like to take consistent snapshot backups of your entire database without a SAN or external software, and without slowing or locking your database for the duration?

RedHat? Enterprise Linux (and Centos Linux) install an LVM by default.
LVM, Logical Volume Manager is a layer that sits on top of any file system (default ext3).

You can tell if you're already running on an LVM, by checking your file system with "df -h" — an entry like "/dev/mapper/VolGroup01-LogVol00" shows that your disk is mapped through the LVM.

LVM brings you features such as the ability to grow and shrink volumes, add hard disks without migrating data, RAID0, and for the purpose of this article: file system SNAPSHOTS.

FLUSH TABLES WITH READ LOCK;
\! lvcreate --size 100m --snapshot --name snap …

"Hot Backups" of your MySQL Database on Linux

Would you like to take consistent snapshot backups of your entire database without a SAN or external software, and without slowing or locking your database for the duration?

RedHat? Enterprise Linux (and Centos Linux) install an LVM by default.
LVM, Logical Volume Manager is a layer that sits on top of any file system (default ext3).

You can tell if you're already running on an LVM, by checking your file system with "df -h" — an entry like "/dev/mapper/VolGroup01-LogVol00" shows that your disk is mapped through the LVM.

LVM brings you features such as the ability to grow and shrink volumes, add hard disks without migrating data, RAID0, and for the purpose of this article: file system SNAPSHOTS.

FLUSH TABLES WITH READ LOCK;
\! …

In Chicago now, and tonight is the (moved from Monday) local MySQL UG meeting, from 7pm. See : http://mysql.meetup.com/5/ (the group) and http://mysql.meetup.com/5/events/4892024/ (this event) for full details.
If you're in the Chicago area, do drop in, say hi, and ask any questions! Mark Matthews (MySQL Java and Windows lead) and I will be there from MySQL, plus assorted users. Should be good! I've got an autographed book by Guy Harrison (the new Stored Procedures one) to hand out to someone, and a few "what's your uptime?" shirts.

This is probably a dumb question, but I’ll put it forth anyway. Is there a routine or easy way to limit the number of items in a group? What I want to do is limit the number of items in a group to no more than a certain number. For instance, the last 10 times someone logged in.

I’m thinking of a routine that takes in field1, field2, # limit, and then an optional keyword of {FIRST,LAST} and maybe an optional WHERE clause. So in an example, the routine would take in:

uid
lastLoginTime
10
FIRST
uid=12345

and the routine would find the number of times uid 12345 logged in. If it’s less than or equal to 10, leave it alone. If it’s greater than 10, delete it so it gets to 10, deleting the oldest records first.

This is not something that could be done with a trigger (ie, on insert of a new login, check to see how many logins there are, and if there are 10 delete the first (oldest) …

So, the “MySQL Gotchas” page was mentioned in one of the talks at the conference last week. The page itself is at:

http://sql-info.de/mysql/gotchas.html

Now, to go through it all…..