Planet MySQL Planet MySQL: Meta Deutsch Español Français Italiano 日本語 Русский Português 中文
10 Newer Entries Showing entries 31 to 40 of 784 10 Older Entries

Displaying posts with tag: performance (reset)

Testing the Fastest Way to Import a Table into MySQL (and some interesting 5.7 performance results)
+2 Vote Up -0Vote Down

As I mentioned on my last post, where I compared the default configurations options in 5.6 and 5.7, I have been doing some testing for a particular load in several versions of MySQL. What I have been checking is different ways to load a CSV file (the same file I used for testing the compression tools) into MySQL. For those seasoned MySQL DBAs and programmers, you …

  [Read more...]
The Query Rewrite Plugins
Employee_Team +1 Vote Up -0Vote Down

Why Query Rewrites?

Now that the cost model project is progressing, most of you are going to notice execution plan changes. In the vast majority of the cases, the changes will be for the better, and some bugs with a long history will finally be closed. In some cases, however, you will notice that your queries run slower. This is inevitable: even if the MySQL optimizer is doing a much better job with the information it has, it may still be the case that the information was incomplete and that the best plan was, in fact, found by not trusting …

  [Read more...]
Optimizer Cost Model Improvements in MySQL 5.7.5 DMR
Employee_Team +0 Vote Up -0Vote Down

In a previous blog post we presented some of the issues with the current optimizer cost model and listed several ideas for improvements. The new 5.7.5 DMR contains the result of our initial work on improving the optimizer’s cost model:

  • Cost Model for WHERE Conditions. In previous versions of MySQL, the estimated number of rows from a table that will be joined with the next table only takes into account the …
  [Read more...]
Hard Drive Reliability
+0 Vote Up -0Vote Down

Cloud service provider Backblaze has updated its earlier study of hard drive failure rates (Nov 2013) in its own infrastructure – from 27,000 to more than 34,000 drives, and the new report (Sep 2014) is quite informative. Hitachi comes out pretty high, Western Digital has produced some good drives, but Seagate tends to come out worst. Each brand does have good and not-so-good models so there’s no single right answer, and for any new model you’ll always be dealing with an …

  [Read more...]
Better Performance for JOINs Not Using Indexes
Employee_Team +1 Vote Up -0Vote Down

In some cases it is not possible to use an index to optimize a JOIN. This may for example happen when you query the Performance Schema. As a result these kind of queries can be very slow; however in MySQL 5.6 and later you can use a trick to improve the performance considerably.

As a working example in this post, I will use the schema_table_statistics view in the sys schema. Since the view involves the schema, I will create a reasonable large number of databases …

  [Read more...]
Which Compression Tool Should I Use for my Database Backups? (Part II: Decompression)
+0 Vote Up -0Vote Down

On my post last week, I analysed some of the most common compression tools and formats, and its compression speed and ratio. While that could give us a good idea of the performance of those tools, the analysis would be incomplete without researching the decompression. This is particularly true for database backups as, for those cases where the compression process is performed outside of the production boxes, you may not care too much about compression times. In that case, even if it is relatively slow, it …

  [Read more...]
Items Affecting Performance of the MySQL Database
Employee_Team +1 Vote Up -0Vote Down

To learn about the many factors that can affect the performance of the MySQL Database, take the MySQL Performance Tuning course.

You will learn:

  • How your hardware and operating system can affect performance
  • How to set up and logging to improve performance
  • Best practices for backup and recovery
  • And much more

You can take this 4-day instructor-led course through the following formats:

  [Read more...]
The Road to MySQL 5.6 -- A DBA Perspective
+4 Vote Up -0Vote Down

We've all heard the hype.  MySQL 5.6 is packed with amazing new features that address all our database problems.  5.6 deals with replication and HA and performance and monitoring and  …

  [Read more...]
Performance evaluation of MariaDB 10.1 and MySQL 5.7.4-labs-tplc
+0 Vote Up -0Vote Down

Introduction

Evaluating the performance of database systems is a very demanding task. There are a lot of hard choices to be made, e.g.:

  • What operating system and operating system version is to be used
  • What configuration setup is to be used
  • What benchmarks are to be used and how long are the warm-up and measure times
  • What test setups are to be used
  • What version of the database management system is used
  • What storage engine is used

While performance evaluation is mostly machine time, there is still a lot of hard work for the human …

  [Read more...]
Prewarm your EBS backed EC2 MySQL slaves
+1 Vote Up -0Vote Down

This is the story of cold blocks and mismatched instances and how they will cause you pain and cost you money until you understand why.

Most of the clients that we support run on the Amazon cloud using either RDS or running MySQL on plain EC2 instances using (Provisioned IOPS) PIOPS EBS for data storage.

As expected the common architecture is running a master with one or more slaves handling the read traffic.

A common problem is that after the slaves are provisioned (normally created from an EBS snapshot) they lag badly due to slow IO performance.

Unfortunately what tends to be lost in the “speed of provisioning new …

  [Read more...]
10 Newer Entries Showing entries 31 to 40 of 784 10 Older Entries

Planet MySQL © 1995, 2015, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.