Showing entries 14851 to 14860 of 44917
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Some LSI 9211-8i issues on Windows and Linux
tl;dr:
Make sure you flash an LSI-9211 to IT firmware rev#14 to get it to work 
with Linux and SSD trim.  You may have to downgrade from newer firmware
to older firmware to get the card to work.



Finding a SATA III controller with more than one PCI-e lane
After a recent hardware issue I decided to upgrade my computer to use new Intel 520 120MB SSD drives in RAID for improved performance.  The motherboard I use (an ASUS Rampage III extreme) has a Marvel SATA III controller with two ports, but I discovered that it is connected via only a single PCI-e lane (each lane can do at most 400MB/sec*).  This means that it can't effectively support even a single Intel 520 because one device can saturate the SATA III bus (An Intel 520 is rated at up to 550MB/sec sequential write).

So I went on a quest for a new SATA 3 controller.   To Frys! I exclaimed.  But unfortunately, all the PCI-e 2.x SATA III …

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The ARCHIVE Storage Engine

I wonder how much longer the ARCHIVE storage engine is going to ship with MySQL…. I think I’m the last person to actually fix a bug in it, and that was, well, a good number of years ago now. It was created to solve a simple problem: write once read hardly ever. Useful for logs and the like. A zlib stream of rows in a file.

You can actually easily beat ARCHIVE for INSERT speed with a non-indexed MyISAM table, and with things like TokuDB around you can probably get pretty close to compression while at the same time having these things known as “indexes”.

ARCHIVE for a long time held this niche though and was widely and quietly used (and likely still is). It has the great benefit of being fairly lightweight – it’s only about 2500 lines of code (1130 if you exclude azio.c, the slightly modified gzio.c from zlib).

It also use the table discovery mechanism that NDB uses. If you remove the FRM file for an ARCHIVE …

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Delayed row-based replication with large tables lacking a primary key

I configure all our master databases to use row-based binary logging where I work. In my opinion it is a much safer option than statement-based replication. The advantages and disadvantages of both types of MySQL replication are detailed in the online documentation here. You can't view the events a slave is applying directly with 'show processlist' but by issuing 'show open tables where in use' you can detect what table is receiving the attention of the SQL thread. If you need more information the mysqlbinlog command must be used to decode the slaves relay logs or masters binary logs.

Our developers often change a lot of rows with a single update statement. This usually results in some reasonable replication lag on downstream slaves. Occasionally the lag continues to grow and eventually nagios …

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Presenting at tomorrow’s Effective MySQL Meetup (New York City)

At tomorrow’s Effective MySQL Meetup, I’ll be presenting “Fractal Tree Indexes : Theory and Practice (MySQL and MongoDB).” The meetup is at 6:30pm Tuesday, May 14, 2013, and will be held at Alley NYC in New York City.

I’ll give an overview on how Fractal Tree® indexes work, and then get into specific product features that Fractal Trees enable in MySQL and MongoDB.  Some benchmarking and customer use-cases will be discussed, but my intent is for this to be a deep technical dive.  Several Tokutek Engineers will also be on hand, so bring any questions you’ve got.

I hope to see you there!

Version 1.6 of mysqljsonimport now available

Yes, finally! This took some time, but I have been so busy with other things, work-related as well as domestic, that I just haven't had the time for this. But finally version 1.6 is available for download from sourceforge. The downloads is as usual the autoconf enabled source code and PDF documentation in PDF.

So, what is new you ask, well there is one big new feature which took a lot more effort than I expected. When this program was written at first, I still have the table/use use in mind. What this means is that I visioned JSON objects to be mapped to a table. This is not how programmers view JSON, but this is how data is viewed in many databases, even NoSQL ones such as MongoDB. So I wanted an import tool for simple row-structured JSON objects.

Now, there is a different way to look at things, which is …

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#DBHangops for 5/15/13 — Filesystems, monitoring, settings, Oh my!

Here’s the recording!

Heyo!

Now that we’ve gone through the Percona Live MySQL Conference and Expo review and had an amazing turnout to talk about it, it’s time to open up the discussion around things that DBAs want to talk about and need to be conscientious of. Join us on Wednesday at 12:00pm PDT (19:00 GMT) to take part in the discussion and share your knowledge and experience with the following topics:

  • Filesystems and MySQL — Which do you use and why?
    • Do you handle I/O alignment? How do you do it?
    • Scheduler changes?
  • Nagios checks! — Any new checks you’ve added recently?
  • The worst settings in MySQL that you always change
  • What are the most important variables to you, and what do you set them to?
  • What will be important variables in 5.6 that …
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OurSQL Episode 139: Starting to Perform

This week we discuss the basics of using the performance schema in MySQL 5.5 and 5.6. Ear Candy is about a temporal gotcha when using dates and times that do not exist, and At the Movies is David Stokes giving some useful for System Administrators who also are in a DBA role.

News
Continuent's Tungsten Replicator is now completely open source
TokuDB is now open source

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Foreign Data Wrappers

Original images from Flickr user jenniferwilliams

One of our clients, for various historical reasons, runs both MySQL and PostgreSQL to support their website. Information for user login lives in one database, but their customer activity lives in the other. The eventual plan is to consolidate these databases, but thus far, other concerns have been more pressing. So when they needed a report combining user account information and customer activity, the involvement of two separate databases became a significant complicating factor.

In similar situations in the past, using earlier versions of PostgreSQL, we've written scripts to pull data from MySQL and dump it into PostgreSQL. This works well enough, but we've updated …

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Webinar: MySQL 5.6 Performance Schema

This Wednesday, May 15 at 10 a.m. Pacific, I’ll be leading  a Webinar titled, “Using MySQL 5.6 Performance Schema to Troubleshoot Typical Workload Bottlenecks.

In this Webinar I will offer an overview of Performance Schema, focusing on new features that have been added in MySQL 5.6, go over the configuration and spend most time showing how you can use the wealth of information Performance Schema gathers to understand some of the typical performance bottlenecks.

 

Other areas of focus include:

  • Bottlenecks with Disk IO
  • Problems with excessive temporary tables and external sorts
  • Excessive internal mutex contention …
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MySQL Thread Pool in 5.6

MySQL Enterprise Edition included the thread pool in its MySQL 5.5 version. We have now updated the thread pool also for the MySQL 5.6 Enterprise Edition.

You can try it for free at trials

The MySQL thread pool is developed as a plugin and all the interfaces needed by the thread pool are part of the MySQL community server enabling anyone to develop their own version of the MySQL thread pool. As part of the development of the thread pool we did a lot of work to make it possible to deliver stand-alone plugins using the interfaces provided by the MySQL server. Most of these interfaces were available already in MySQL 5.1, but we extended them and made them more production ready as part of MySQL 5.5 development. So a plugin can easily define their own configuration variables and their own information schema tables and also easily use performance schema extensions. A …

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