Mysql low priority write a check

I can easily find these duplicate rows and can run a single delete query to kill them all.

Mysql low priority write a check

Uptime Uptime shows how long the system has been running.

mysql low priority write a check

You can see the same information by running uptime: The second number is how much of that time the machine has spent idle, in seconds The second value may be greater than the overall system uptime on systems with multiple cores since it is a sum.

How did I know that? I looked at what files the uptime program opens when it is run. We can use the strace tool to do that. We can grep for the open system call. But that will not really work since strace outputs everything to the standard error stderr stream.

Our output is this: It turns out that you can also use strace -e open uptime and not bother with grepping. So why do we need the uptime program if we can just read the contents of the file? The uptime output is nicely formatted for humans whereas the number of seconds is more useful for using in your own programs or scripts.

Load average In addition to uptime, there were also three numbers that represent the load average. If you take another look at the strace output, you'll see that this file was also opened. The fourth column shows the number of currently running processes and the total number of processes.

The last column displays the last process ID used.


Let's start with the last number. Whenever you launch a new process, it is assigned an ID number. Process IDs are usually increasing, unless they've been exausted and are being reused.

When it's launched in the background, its process ID will be shown. When you run htop and see just one running process, it means that it is the htop process itself. If you run sleep 30 and run htop again, you'll notice that there is still just 1 running process.

That's because sleep is not running, it is sleeping or idling or in other words waiting for something to happen.

mysql low priority write a check

The load average represents the average system load over a period of time. The load number is calculated by counting the number of running currently running or waiting to run and uninterruptible processes waiting for disk or network activity. So it's simply a number of processes. The load averages are then the average number of those processes during the last 1, 5 and 15 minutes, right?

It turns out it's not as simple as that. The load average is the exponentially damped moving average of the load number. Mathematically speaking, all three values always average all the system load since the system started up.

They all decay exponentially, but they decay at different speed.htop explained. Explanation of everything you can see in htop/top on Linux. Last updated on January 2, #1 on Hacker News on December 2, #1 on /r/sysadmin on December 2, Jul 10,  · That’s great.

I hope it will make the next major update, with the ability to put it on a different drive. At the *very* least, I need to be able to set aside a portion of a larger drive and mount it inside the distro..

I used to be a MySQL DBA for Hire – Now I am only a MySQL DBA :-)

i just plain need a ton of space for my linux command line, and I don’t want to move my Windows user directory, off of my SSD. MySQL supports two modifiers in the UPDATE statement. The LOW_PRIORITY modifier instructs the UPDATE statement to delay the update until there is no connection reading data from the table.

The LOW_PRIORITY takes effect for the storage engines that use table-level locking only, for example, MyISAM, MERGE, MEMORY. I am happy that the MySQL team is, during the last years, blogging about each major feature that MySQL Server is getting; for example, the series on Recursive Common Table extremely busy myself, I appreciate taking the time to share details with the .

One of the most important tasks any developer needs to do often is back up their MySQL database. In many cases, the database is what drives most of the site. While most web hosts do a daily backup of a customer's database, relying on them to make backups and provide them at no cost is risky to say.

Normally, MySQL does a write of all changes to disk only after each SQL statement and lets the operating system handle the synchronizing to disk. See Section B, “What to Do If MySQL .

htop explained |